THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED
     UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR THE SECURITIES LAWS OF ANY
     STATE OF THE UNITED STATES. THE SECURITIES REPRESENTED HEREBY MAY NOT BE
     OFFERED OR SOLD OR OTHERWISE TRANSFERRED IN THE ABSENCE OF AN EFFECTIVE
     REGISTRATION STATEMENT FOR THE SECURITIES UNDER APPLICABLE SECURITIES LAWS,
     OR UNLESS OFFERED, SOLD OR TRANSFERRED PURSUANT TO AN AVAILABLE EXEMPTION
     FROM THE REGISTRATION REQUIREMENTS OF THOSE LAWS. THE INDEBTEDNESS OF THE
     COMPANY EVIDENCED HEREBY IS SUBJECT TO THE RIGHTS OF LASALLE NATIONAL BANK,
     ITS SUCCESSORS AND ASSIGNS, UNDER A SUBORDINATION AGREEMENT DATED APRIL 15,
     1999.


                      6% SUBORDINATED CONVERTIBLE DEBENTURE

     April    , 1999                                                $          

          FOR   VALUE  RECEIVED,   Westell  Technologies,   Inc.,   a  Delaware
     corporation (hereinafter  called the "Borrower" or  the "Company"), hereby
     promises     to      pay     in      cash     to     the      order     of
                                                              or      registered
     assigns or transferees of all or any portion hereof (each a "Holder" and,
     collectively, "Holders") the aggregate sum of million dollars
     ($____________) on April 15, 2004 [fifth anniversary of issuance] (the
     "Scheduled Maturity Date"), and to pay interest, in arrears, on (i) the
     last day of June and December of each year (unless such day is not a
     business day, in which event on the next succeeding business day) (each, an
     "Interest Payment Date"), (ii) the Scheduled Maturity Date, and (iii) the
     date the principal amount of the Debentures shall be declared to be or
     shall automatically become due and payable, on the unpaid principal sum
     hereof outstanding at the rates per annum set forth below, from the most
     recent Interest Payment Date to which interest has been paid on this
     Debenture, or if no interest has been paid on this Debenture, from the day
     after the date of this Debenture (the "Issue Date") until payment in full
     of the principal sum hereof has been made.

          The interest rate shall be the six percent (6%) per annum, but the
     interest rate shall be eight percent (8%) per annum if the Green Floor
     Price (as defined below) is or has ever been the applicable conversion
     price (the "Interest Rate"). Past due amounts (including interest, to the
     extent permitted by law) will also accrue interest at the lesser of (a) the
     Interest Rate plus 5% per annum and (b) the maximum rate permitted by
     applicable law, and will be payable on demand ("Default Interest").
     Interest on this Debenture will be calculated on the basis of a 365-day
     year. All payments under this Debenture made in cash shall be made by wire
     transfer of immediately available funds in currency of the United States of
     America to such account as the Holders shall hereafter give to the Borrower
     by written notice made in accordance with the provisions of this Debenture.

          At the option of the Company, interest may be paid in cash, in
     debentures in the form hereof ("PIK Debentures") or in shares of the
     Company's Class A Common Stock, par value $0.01 per share (the "Class A
     Common Stock" and, together with all other classes and series of the common
     stock of the Company, the "Common Stock"), provided, however, that the
     Company may not pay interest in PIK Debentures or in shares of Class A
     Common Stock unless (a) no Event of Failure (as defined below) (and no
     event which, with notice or passage of time, would constitute an Event of
     Failure) has occurred and is continuing, (b) the shares of Class A Common
     Stock issuable (whether directly or pursuant to the PIK Debentures) have
     been registered for resale in an appropriate and an effective registration
     statement under the Securities Act of 1933, as amended, available for
     immediate use by the Holder and such shares are qualified or exempt under
     applicable state securities laws so that the Holder may immediately
     thereafter resell such shares of Class A Common Stock, (c) the shares of





     Class A Common Stock issuable (whether directly or pursuant to the PIK
     Debentures) are listed for trading on The Nasdaq National Market and (d)
     such shares of Class A Common Stock are, in the case of the PIK Debentures,
     reserved for issuance in accordance with the Reserved Amount (as defined
     below) requirement of Section 4.1 hereof. If the Company determines to pay
     interest in shares of Class A Common Stock or PIK Debentures, it shall be
     required to notify the Holder of such election at least five (5) business
     days prior to the applicable Interest Payment Date. The principal amount of
     Debentures to be issued as interest shall be equal to the dollar amount of
     interest due at the time of payment. The number of shares of Class A Common
     Stock issued as interest shall be the number determined by dividing the
     dollar amount of interest due by an amount equal to the average of the
     Closing Sale Prices of the Class A Common Stock for the five (5) business
     days prior to the date interest is so paid.

          This 6% Subordinated Convertible Debenture is one of a duly authorized
     issuance of Twenty Million Dollars ($20,000,000) aggregate principal amount
     of Subordinated Convertible Debentures of the Company (each, a "Debenture")
     referred to in the Securities Purchase Agreement dated April 14, 1999 among
     the Company and the initial Holders (the "Securities Purchase Agreement").
     The Securities Purchase Agreement contains certain additional agreements
     among the parties with respect to the terms of this Debenture. All such
     provisions are an integral part of this Debenture and are incorporated
     herein by reference. All terms defined in the Securities Purchase Agreement
     and not otherwise defined herein shall have for purposes hereof the
     meanings provided for therein. This Debenture is transferable and
     assignable to one or more purchasers (in minimum denominations of $500,000
     or larger multiples of $100,000 or lesser remaining outstanding principal
     amounts), in accordance with the limitations set forth in the Securities
     Purchase Agreement.

          The Company agrees, and the Holder by accepting this Debenture agrees,
     that the indebtedness evidenced by this Debenture and the payment of the
     principal thereof and interest thereon and all other amounts owing in
     respect thereof are subordinated in right of payment to the prior payment
     in full in cash of all Permitted Senior Indebtedness of the Company and
     that the subordination is for the benefit of the holders of Permitted
     Senior Indebtedness of the Company, all of the foregoing to the extent
     provided herein. "Permitted Senior Indebtedness" shall have the meaning
     ascribed thereto in the Securities Purchase Agreement under clauses (i) and
     (iv)(b) of the definition thereof.

     If there should occur with respect to the Company any receivership,
     insolvency, assignment for the benefit of creditors, bankruptcy,
     reorganization or arrangements with creditors (whether or not pursuant to
     bankruptcy or other insolvency laws), sale of all or substantially all of
     the assets, dissolution, liquidation or any other marshaling of the assets
     and liabilities of the Company, or if this Debenture shall be declared due
     and payable solely upon the occurrence of an event of default with respect
     to any Permitted Senior Indebtedness, then no amount shall be paid by the
     Company in respect of the principal of or interest on this Debenture at the
     time outstanding, unless and until the principal of and interest on the
     Permitted Senior Indebtedness then outstanding shall be paid in full.

     Subject to the provisions of the Subordination Agreement (as defined in the
     Securities Purchase Agreement) and the rights, if any, of the holders of
     Permitted Senior Indebtedness as herein provided to receive cash,
     securities or other properties otherwise payable or deliverable to the
     Holder of this Debenture, nothing contained herein shall impair, as between
     the Company and the Holder, the obligation of the Company, subject to the
     terms and conditions hereof, to pay to the Holder amounts due hereunder as
     and when the same become due and payable, or shall prevent the Holder of
     this Debenture from exercising all rights, powers and remedies otherwise
     provided herein or by applicable law.





     Subject to the payment in full of all Permitted Senior Indebtedness and
     until this Debenture shall be paid in full, the Holder shall be subrogated
     to the rights of the holders of Permitted Senior Indebtedness (to the
     extent of payments or distributions previously made by the Holder to such
     holders of Permitted Senior Indebtedness pursuant to the Subordination
     Agreement) to receive payments or distributions of assets of the Company
     applicable to the Permitted Senior Indebtedness. No such payments or
     distributions applicable to the Permitted Senior Indebtedness shall, as
     between the Company and its creditors, other than the holders of Permitted
     Senior Indebtedness and the Holder, be deemed to be a payment by the
     Company to or on account of this Debenture; and for the purposes of such
     subrogation, no payments or distributions to the holders of Permitted
     Senior Indebtedness to which the Holder would be entitled except for the
     foregoing provisions shall, as between the Company and its creditors, other
     than the holders of Permitted Senior Indebtedness and the Holder, be deemed
     to be a payment by the Company to or on account of the Permitted Senior
     Indebtedness.

     Notwithstanding anything to the contrary, Holders may receive (i) shares of
     Series A Common Stock upon conversion of the Debentures, (ii) Cap
     Debentures issued pursuant to the Debentures, and (iii) PIK Debentures
     issued pursuant to the Debentures.

     The obligations of Company under this Debenture, the PIK Debentures and the
     Cap Debentures shall be secured by a security interest and lien on all of
     the Company s assets (including any equity interest in its subsidiaries)
     subject only to the prior security interests and liens granted to the
     holders of Permitted Senior Indebtedness as set forth in a separate
     Security Agreement to be executed by the Company in favor of the Holders of
     such Debentures (the "Security Agreement").

                                    ARTICLE I
                                   REDEMPTION

          1.1 Limited Right to Prepay or Redeem. Except as provided herein, this
     Debenture may not be prepaid or redeemed by the Company without the prior
     written consent of all Holders.

          1.2  Redemption at Borrower's Option.

               (a) At any time after the first (1st) anniversary of the date of
     the Closing, the Borrower shall have the right ("Redemption at Borrower's
     Election") to redeem, subject to the limitations herein contained, all or
     any portion of the then outstanding Debentures for the Optional Redemption
     Amount (as herein defined) which right shall be exercisable at any time
     during the term of this Debenture after the first (1st) anniversary of the
     date of the Closing by delivery of an Optional Redemption Notice in
     accordance with the redemption procedures set forth in this Article I. Any
     Redemption at Borrower's Election pursuant to this Section 1.2 shall be
     made ratably among Holders in proportion to the principal amount of
     Debentures then outstanding. Subject to the limitations on conversion
     contained herein, Holders may convert all or any part of their Debentures
     selected for prepayment hereunder into Common Stock at the Conversion Price
     by delivering a Notice of Conversion to the Borrower at any time prior to
     the Effective Time of Redemption (as herein defined). The "Optional
     Redemption Amount" with respect to each Debenture means one hundred fifteen
     percent (115%) of the face amount of the Debentures to be redeemed plus
     accrued and unpaid interest. In no event shall the Borrower be permitted to
     elect a redemption pursuant to this Article I of a principal amount of
     Debentures which, if all such principal amount of Debentures subject to
     redemption were immediately converted into Common Stock pursuant to the
     terms hereof, would, solely as a result of such conversion and without
     regard to Section 3.7(b) hereof, result in any Holder owning in excess of
     4.9% of the Class A Common Stock (the "4.9% Limitation"). A Redemption at
     Borrower s Election shall be for not less than $2,000,000 aggregate
     principal amount of Debentures or such maximum





     lesser amount as would not cause the 4.9% Limitation to be exceeded as to
     any holder of Debentures. Furthermore, prior to Shareholder Approval (as
     defined in the Securities Purchase Agreement), unless otherwise permitted
     by The Nasdaq National Market or unless the rules thereof no longer are
     applicable to the Company, in no event shall the Borrower be permitted to
     elect a redemption pursuant to this Article I of a principal amount of
     Debentures which, if all such principal amount of Debentures subject to
     redemption were immediately converted into Common Stock pursuant to the
     terms hereof, would, solely as a result of such conversion and without
     regard to Section 3.7(a) hereof, result in any Holder owning in excess of
     4.9% such Holder allocable portion of the Cap Amount.

               (b) The Borrower may not deliver an Optional Redemption Notice
     (as defined below) to a Holder unless:

                    (i) on or prior to the date of delivery of such Optional
          Redemption Notice, the Borrower shall have deposited with an escrow
          agent reasonably satisfactory to such Holder, as a trust fund, cash
          sufficient in amount to pay all amounts to which Holders are entitled
          upon such prepayment pursuant to Subsection (a) of this Section 1.2,
          with irrevocable instructions and authority to such escrow agent to
          complete the prepayment thereof in accordance with this Section 1.2;
          and

                    (ii) either (I) the weighted average sale price of the
          Common Stock as reported by Bloomberg Financial Markets or a
          comparable reporting service of national reputation selected by the
          Company and reasonably acceptable to each initial holder of the
          Debentures (the "Weighted Average Sale Price") is greater than or
          equal to two hundred percent (200%) of the Variable Conversion Price
          (as defined below) then in effect for the twenty (20) consecutive
          trading days immediately preceding the date of delivery of such
          Optional Redemption Notice, or (II) the Company consolidates or merges
          with any other corporation or entity and the consideration being
          provided to the holders of Common Stock in such merger or
          consolidation is at least two hundred percent (200%) of the Variable
          Conversion Price then in effect.

               Any Optional Redemption Notice delivered in accordance with this
     subsection (b) shall be accompanied by a statement executed by a duly
     authorized officer of its escrow agent, certifying the amount of funds
     which have been deposited with such escrow agent and that the escrow agent
     has been instructed and agrees to act as prepayment agent hereunder.

               (c) The Borrower shall effect the Redemption at Borrower s
     Election under this Section 1.2 by giving prior written notice (the
     "Optional Redemption Notice"), which notice may only be delivered on a
     business day, twenty (20) business days prior to the date on which such
     prepayment is to become effective (the "Effective Time of Redemption") to
     Holders of Debentures selected for prepayment at the address and facsimile
     number of such Holder appearing in the Borrower's register for the
     Debentures. Following delivery of an Optional Redemption Notice, the
     Borrower may not deliver another Optional Redemption Notice prior to the
     Effective Time of Redemption with respect to such existing Optional
     Redemption Notice. The Optional Redemption Notice shall indicate the
     Debentures selected for prepayment and the Optional Redemption Amount. The
     Optional Redemption Notice shall be deemed to have been delivered to a
     Holder: (i) if such fax is received by such holder on or prior to 3:00 p.m.
     Chicago time, on the time and date of transmission of Borrower's fax; and
     (ii) if such fax is received by Holder after 3:00 p.m. Chicago time, on the
     next business day following the date of transmission of Borrower's fax;
     provided that, for any notice required under this subsection 1.2(c) to be
     valid, a copy of such notice must be sent to the Holders on the same day by
     overnight courier.

               (d) The Optional Redemption Amount shall be paid to each Holder





     whose Debentures are being prepaid at the Effective Time of Redemption;
     provided, however, that (i) the Borrower shall not be obligated to deliver
     any portion of the Optional Redemption Amount until either the Debentures
     being prepaid are delivered to the office of the Borrower or the escrow
     agent as provided in this subsection 1.2(d), or such Holder notifies the
     Borrower or the escrow agent that such Debentures have been lost, stolen or
     destroyed and delivers documentation in accordance with Section 10.10
     hereof and (ii) the aggregate principal amount of Debentures of any Holder
     that the Borrower shall be entitled to redeem in connection with any
     Optional Redemption Notice shall be reduced by the aggregate principal
     amount of Debentures which are converted (or with respect to which a Notice
     of Conversion (as defined in Section 3.1) is delivered to the Company)
     after delivery to such Holder of such Optional Redemption Notice and prior
     to the Effective Time of Redemption. Notwithstanding anything herein to the
     contrary, in the event that the Debentures being prepaid are not delivered
     to the Borrower or the escrow agent prior to the second business day
     following the Effective Time of Redemption, the prepayment of the
     Debentures pursuant to this Section 1.2 shall still be deemed effective as
     of the Effective Time of Redemption and the Optional Redemption Amount
     shall be paid to each Holder whose Debentures are being prepaid by 5:00
     p.m., Chicago time, on the next business day following the date on which
     the Debentures are actually delivered to the Borrower or the escrow agent.

               (e) If the Borrower fails to deliver the Optional Redemption
     Amount to the Holder on or before the Optional Redemption Date (an
      Optional Redemption Default ), the Borrower shall pay to Holder an amount
     equal to:

          (.24) x (D/365) x (Optional Redemption Amount)

     where:

           D means the number of days from the Optional Redemption Date through
     and including the date on which the Borrower delivers the Optional
     Redemption Amount to the Holder.

          The payments to which Holder shall be entitled pursuant to this
     subparagraph (e) are referred to herein as Redemption Default Payments.

               (f) In the event of any Optional Redemption Default, the Holder
     shall have the right (without limiting damages hereunder, the right to
     Redemption Default Payments or any other right or remedy), at any time
     prior to the Borrower s delivery of the Optional Redemption Amount to the
     Holder, to continue to treat the portion of this Debenture which was
     subject to redemption as outstanding for all purposes hereof, including
     conversion in accordance with the procedures set forth in Article III
     hereof at, however, the lowest Conversion Price in effect during the period
     beginning on, and including, the date of the Optional Redemption Notice
     which triggered the Borrower s rights pursuant to Section 1.2(a) above
     through and including the day shares of Class A Common Stock are delivered
     to the Holder upon such a conversion (assuming, for these purposes, that
     the Market Conversion Price is in effect). In addition, if the Borrower
     fails to pay an Optional Redemption Amount when due and owing, the Borrower
     shall thereafter forfeit its rights under this Article I to effect
     Redemption at Borrower s Election.

               (g) Notwithstanding the provisions of this Article I, (i) during
     the continuance of an Event of Failure and until cured or any occurrence
     which would with the passage of time, the giving of notice and/or the
     continuance thereof result in an Event of Failure and until cured and (ii)
     during any Permitted Blackout (as defined in the Registration Rights
     Agreement dated April 15, 1999 among the Company and the initial Holders
     (the "Registration Rights Agreement")), the Borrower shall lose its right
     to Redemption at Borrower's Election.





                                   ARTICLE II
                               CERTAIN DEFINITIONS

          2.1 The following terms shall have the following meanings:

               (a) "Bankruptcy Event" shall mean any one or more of the
     following: (i) the commencement of any voluntary proceeding by the Company
     seeking entry of an order for relief under Title 11 of the United States
     Code or seeking any similar or equivalent relief under any other applicable
     federal or state law concerning bankruptcy, insolvency, creditors' rights
     or any similar law; (ii) the making by the Company of a general assignment
     for the benefit of its creditors; (iii) the commencement of any involuntary
     proceeding respecting the Company seeking entry of an order for relief
     against the Company in a case under Title 11 of the United States Code or
     seeking any similar or equivalent relief under any other applicable federal
     or state law concerning bankruptcy, insolvency, creditors' rights or any
     similar law; (iv) entry of a decree or order respecting the Company by a
     court having competent jurisdiction, which decree or order (x) results in
     the appointment of a receiver, liquidator, assignee, examiner, custodian,
     trustee, sequestrator (or other similar official) for the Company or for
     any substantial part of its property or (y) orders the winding up,
     liquidation, dissolution, reorganization, arrangement, adjustment, or
     composition of the Company or any of its debts; (v) the appointment,
     whether or not voluntarily by the Company, of a receiver, liquidator,
     assignee, examiner, custodian, trustee, sequestrator (or other similar
     official) for the Company or for any substantial part of its property; (vi)
     the failure by the Company to pay, or its admission in writing of its
     inability to pay, its debts generally as they become due; (vii) the
     exercise by any creditor of any right in connection with an interest of
     such creditor in any substantial part of the Company's property, including,
     without limitation, foreclosure upon all or any such part of the Company's
     property, replevin, or the exercise of any rights or remedies provided
     under the Uniform Commercial Code with regard thereto; (viii) the making
     of, or the sending of a notice of, a bulk transfer by the Company; (ix) the
     calling by the Company of a general meeting of its creditors or any portion
     of them; (x) the failure by the Company to file an answer or other pleading
     denying the material allegations of any proceeding described herein that is
     filed against it; and (xi) the consent by the Company to any of the
     actions, appointments, or proceedings described herein or the failure of
     the Company to contest in good faith any such actions, appointments, or
     proceedings. For purposes of this paragraph, the Company shall also refer
     to any material subsidiary thereof.

               (b) "Closing Bid Price" means, for any security as of any date,
     the closing bid price of such security on the principal securities exchange
     or trading market where such security is listed or traded as reported by
     Bloomberg Financial Markets or a comparable reporting service of national
     reputation selected by the Company and reasonably acceptable to each
     remaining initial Holder and, if no remaining initial Holders, the Holders
     of a majority of the aggregate principal amount represented by the then
     outstanding Debentures ("Majority Holders")(it being agreed that the
     consent of the Majority Holders requires the consent of each remaining
     initial Holder, if any) if Bloomberg Financial Markets is not then
     reporting closing bid prices of such security (collectively, "Bloomberg"),
     or if the foregoing does not apply, the last reported sale price of such
     security in the over-the-counter market on the electronic bulletin board of
     such security as reported by Bloomberg, or, if no sale price is reported
     for such security by Bloomberg, the average of the bid prices of any market
     makers for such security as reported in the "pink sheets" by the National
     Quotation Bureau, Inc. If the Closing Bid Price cannot be calculated for
     such security on such date on any of the foregoing bases, the Closing Bid
     Price of such security on such date shall be the fair market value as
     reasonably determined by an investment banking firm selected by the Company
     and reasonably acceptable to the Majority Holders, with the costs of such
     appraisal to be borne by the Company.





               (c) "Closing Sale Price" means, for any security as of any date,
     the closing sale price of such security on the principal securities
     exchange or trading market where such security is listed or traded as
     reported by Bloomberg, or if the foregoing does not apply, the last
     reported sale price of such security in the over-the-counter market on the
     electronic bulletin board of such security as reported by Bloomberg, or, if
     no sale price is reported for such security by Bloomberg, the average of
     the bid prices of any market makers for such security as reported in the
     "pink sheets" by the National Quotation Bureau, Inc. If the Closing Sale
     Price cannot be calculated for such security on such date on any of the
     foregoing bases, the Closing Sale Price of such security on such date shall
     be the fair market value as reasonably determined by an investment banking
     firm selected by the Company and reasonably acceptable to the Majority
     Holders, with the costs of such appraisal to be borne by the Company.

               (d) "Conversion Amount", except as otherwise provided in Section
     3.3, means, (i) the portion of the principal amount of this Debenture
     elected by Holder to be converted (the "Selected Amount"), which amount may
     be all or any portion of the principal amount of this Debenture plus (ii)
     an amount equal to the product of (A) N divided by 365 times (B) .06 (but
     .08 if the Green Floor Price is applicable) times (C) the Selected Amount.

               (e) "Conversion Date" means, for any Optional Conversion, the
     date specified in the Notice of Conversion, or if no date is specified
     therein, the date the Notice of Conversion is faxed or otherwise delivered
     to the Company; provided, however, that the Conversion Date shall not be
     prior to the date of delivery (by facsimile or otherwise) of the Notice of
     Conversion and any Notice of Conversion delivered to the Company on a day
     which is not a business day shall be deemed delivered as of the next
     following business day.

               (f) "Conversion Price" means, with respect to any Conversion
     Date, the lower of the Variable Conversion Price and the Market Conversion
     Price, each as in effect as of such date and subject to adjustment as
     provided herein; provided, however:

                    (i) so long as a Material Adverse Change (as defined below)
          shall not have occurred, if the average Closing Sale Price of the
          Class A Common Stock for the ten (10) consecutive trading days ending
          on the first (1st) anniversary of the date of the Closing (subject to
          equitable adjustment for any stock splits, stock dividends,
          reclassifications or similar events during the such ten (10) trading
          day period) equals or exceeds the one hundred fifty percent (150%) of
          the Variable Conversion Price (as then in effect), then thereafter
          (but only for so long as a Material Adverse Change shall not have
          occurred) the Market Conversion Price may not be used for calculation
          of the Conversion Price; and

                    (ii) during the thirty (30) business day period commencing
          upon the expiration of a Permitted Blackout (as defined in the
          Registration Rights Agreement), the Conversion Price shall mean the
          lesser of (x) the Conversion Price with respect to such Conversion
          Date as determined in accordance with the foregoing provisions of this
          definition and (y) the lowest Conversion Price that would have been
          available during the period of such Permitted Blackout as determined
          in accordance with the foregoing provisions of this definition.

               (g) "Green Floor Price" means $4.4604, which amount equals
     seventy percent (70%) of the initial Variable Conversion Price, subject to
     adjustment as provided herein.

               (h) "Market Conversion Price" means, as of any Conversion Date,
     the lowest average of the Closing Bid Prices of the Class A Common Stock





     occurring over any five (5) consecutive trading days during the ten (10)
     consecutive trading day period ending the day prior to the applicable
     Conversion Date (subject to equitable adjustment for any stock splits,
     stock dividends, reclassifications or similar events during the such ten
     (10) trading day period ) subject to adjustments as provided herein.

               (i) "N" means the number of days from the most recent Interest
     Payment Date to which interest has been paid, as if no Interest Payment
     Date has occurred, the day after the Issue Date to and including the
     Conversion Date, subject to Section 3.2 hereof, as specified in the notice
     of conversion in the form attached hereto (the "Notice of Conversion").

               (j) "Variable Conversion Price" means $6.372, which amount is one
     hundred and thirty five percent (135%) of the average of the closing bid
     price of the Class A Common Stock for the fifteen (15) consecutive trading
     days ending on the second (2nd) trading day immediately preceding the date
     of execution of the Securities Purchase Agreement (the "Initial Variable
     Conversion Price"); provided that on the first (1st) anniversary of the
     Issue Date, the Variable Conversion Price shall be adjusted to the greater
     of (A) the Weighted Average Sales Price of the Class A Common Stock for the
     ten (10) consecutive trading days immediately preceding the date of such
     1st anniversary and (B) the Green Floor Price, unless such adjustment would
     result in an increase in the Variable Conversion Price to a price above the
     Initial Variable Conversion Price hereunder, in which event, thereafter the
     Variable Conversion Price shall be such Initial Variable Conversion Price;
     provided further on the second (2nd) anniversary of the Issue Date, the
     Variable Conversion Price shall be adjusted to the greater of (A) the
     Weighted Average Sales Price of the Class A Common Stock for the ten (10)
     consecutive trading days immediately preceding the date of such 2nd
     anniversary and (B) the Green Floor Price, unless such adjustment would
     result in an increase of the Variable Conversion Price to a price above the
     Initial Variable Conversion Price hereunder, in which event, thereafter the
     Variable Conversion Price shall be such Initial Variable Conversion Price.
     The Variable Conversion Price is subject to further adjustment as provided
     herein.

                                   ARTICLE III
                                   CONVERSION

          3.1 Conversion at the Option of the Holder. Subject to the limitations
     on conversions contained in Section 3.7 hereof, the Holder may, at any time
     and from time to time, convert (an "Optional Conversion") a Conversion
     Amount into a number of fully paid and nonassessable shares of Class A
     Common Stock equal to the number determined by dividing such Conversion
     Amount by the Conversion Price.

          3.2 Mechanics of Conversion. In order to effect an Optional
     Conversion, a Holder (a "Converting Holder") shall fax (or otherwise
     deliver) a copy of the fully executed Notice of Conversion substantially in
     the form of Exhibit A (the "Notice of Conversion") to the Company for the
     Class A Common Stock. Upon receipt by the Company of a facsimile copy of a
     Notice of Conversion from a Converting Holder, the Company shall
     immediately send, via facsimile, a confirmation to the Converting Holder
     stating that the Notice of Conversion has been received, the date upon
     which the Company expects to deliver the Class A Common Stock upon
     conversion and the name and telephone number of a contact person at the
     Company regarding the conversion. Promptly following the faxing (or other
     delivery) of the Notice of Conversion, the Holder shall surrender or cause
     to be surrendered to the Company, this Debenture, along with a copy of the
     Notice of Conversion.

          3.3  Company's Obligations Upon Conversion.

               Delivery of Common Stock.   Subject to Section 3.6  hereof, upon
     the delivery  of a  Notice of  Conversion, the Company  shall, as  soon as
     practicable  but in any event no later than  the later of (a) the day that





     is three business days following the Conversion Date and (b) the day that
     is the first business day following the date of surrender of this Debenture
     (or delivery of documentation in accordance with Section 10.10 hereof) (the
     "Delivery Period"), issue and deliver to the Converting Holder (x) that
     number of shares of Class A Common Stock issuable upon conversion of the
     portion of this Debenture being converted (the "Converted Portion") and (y)
     a new Debenture in the form hereof representing the balance of the
     principal amount hereof not being converted, if any. Delivery under this
     Section 3.3 may be made personally or by reputable overnight courier. The
     person or persons entitled to receive shares of Class A Common Stock
     issuable upon such conversion shall be treated for all purposes as the
     record holder of such shares at the close of business on the Conversion
     Date and such shares shall be issued and outstanding as of such date. The
     Company may elect (the "Cash Election") for any given calendar month to pay
     in cash the accrued and unpaid interest due on the date of delivery of the
     Notice of Conversion on the Converted Portion upon the delivery of all
     Notices of Conversion during such calendar month, rather than issuing
     shares of Class A Common Stock for such amounts; provided, however that the
     Company must deliver to each Holder irrevocable written notice of its Cash
     Election by the twentieth (20th) day of the previous calendar month.

          3.4 Taxes. The Company shall pay any and all taxes (other than
     transfer taxes) which may be imposed with respect to the issuance and
     delivery of the shares of Class A Common Stock upon the conversion of this
     Debenture.

          3.5 No Fractional Shares. No fractional shares of Class A Common Stock
     are to be issued upon the conversion of this Debenture, but the Company
     shall instead round up to the next whole number the number of shares of
     Class A Common Stock to be issued upon such conversion.

          3.6 Conversion Disputes. In the case of any dispute with respect to a
     conversion, the Company shall promptly issue such number of shares of Class
     A Common Stock as are not disputed in accordance with Sections 3.1 and 3.3
     hereof. If such dispute only involves the calculation of the Conversion
     Price, the Company shall submit the disputed calculations to an independent
     accounting firm of national standing (acceptable to the Converting Holder)
     via facsimile within two (2) business days of receipt of the Notice of
     Conversion. The accountant shall audit the calculations and notify the
     Company and the Converting Holder of the results no later than two (2)
     business days from the date it receives the disputed calculations. The
     accountant's calculation shall be deemed conclusive, absent manifest error.
     As soon as possible thereafter, the Company shall then issue the
     appropriate number of shares of Class A Common Stock in accordance with
     Sections 3.1 and 3.3 hereof.

          3.7 Limitations on Conversions. The conversion of this Debenture shall
     be subject to the following limitations (each of which limitations shall be
     applied independently):

               (a) Cap Amount. Prior to Shareholder Approval, unless otherwise
     permitted by The Nasdaq National Market or unless the rules thereof no
     longer are applicable to the Company, in no event shall the total number of
     shares of Common Stock issued upon conversion of the Debentures and
     exercise of the Warrants (as defined in the Securities Purchase Agreement)
     exceed the maximum number of shares of Common Stock that the Company can
     without stockholder approval so issue pursuant to Nasdaq Rule 4460(i) (or
     any successor rule) (the "Cap Amount") upon the conversion of the
     Debentures and the exercise of the Warrants, which, as of the date of
     initial issuance of the Debentures and Warrants, shall be 7,291,107 shares
     (or any such higher number as the rules permit, it being understood and
     agreed that, to the extent required by Nasdaq Rule 4460(i), no shares
     acquired upon conversion of this Debenture or exercise of the Warrants
     shall be entitled to vote in such Shareholder Approval). The Cap Amount
     shall be allocated pro-rata to the Holders as provided in Section 10.1





     hereof. A Holder s allocable portion of the Cap Amount shall be applicable
     to both Debentures and Warrants held by it and shall be applied to such
     Debentures and Warrants on the basis of the time of conversion or exercise,
     as the case may be, thereof.

               (b) No Five Percent Holders. Notwithstanding anything to the
     contrary contained herein, the Debentures shall not be convertible by a
     Holder to the extent (but only to the extent) that, if convertible by such
     Holder, such Holder would beneficially own in excess of 4.9% (the
     "Applicable Percentage") of the shares of Class A Common Stock. To the
     extent the above limitation applies, the determination of whether the
     Debentures shall be exercisable (vis-a-vis other securities owned by Holder
     which contain similar limitations on conversion) and of which Debentures
     shall be exercisable (as among Debentures) shall be made on the basis of
     the earliest submission of the Debentures (vis-a-vis other securities owned
     by the Holder which contain similar limitations on conversion and vis a vis
     other Debentures), in each case subject to such aggregate percentage
     limitation. No prior inability to convert Debentures pursuant to this
     paragraph shall have any effect on the applicability of the provisions of
     this paragraph with respect to any subsequent determination of
     convertibility. For the purposes of this paragraph, beneficial ownership
     and all determinations and calculations, including without limitation, with
     respect to calculations of percentage ownership, shall be determined in
     accordance with Section 13(d) of the Securities Exchange Act of 1934, as
     amended, and Regulation 13D and G thereunder. The provisions of this
     paragraph may be implemented in a manner otherwise than in strict
     conformity with the terms of this Section with the approval of the Board of
     Directors of the Company and the Holder: (i) with respect to any matter to
     cure any ambiguity herein, to correct this paragraph (or any portion
     hereof) which may be defective or inconsistent with the intended Applicable
     Percentage beneficial ownership limitation herein contained or to make
     changes or supplements necessary or desirable to properly give effect to
     such Applicable Percentage limitation; and (ii) with respect to any other
     matter, with the further consent of the holders of a majority of the then
     outstanding shares of Class A Common Stock. For clarification, it is
     expressly a term of this security that the limitations contained in this
     Section shall apply to each successor Holder.

               (c) Material Adverse Change. Notwithstanding anything to the
     contrary contained herein, the Debentures shall not be convertible until
     the earlier of (i) the one hundred eightieth (180th) day following the
     Issue Date, (ii) the occurrence of a Material Adverse Change (as herein
     defined), and (iii) an Operating Expense Reduction Failure. For the
     purposes of this Debenture, a "Material Adverse Change" means any change
     which has a material adverse effect on the business, operations,
     properties, financial condition, or operating results of the Company and
     its subsidiaries, taken as a whole on a consolidated basis; provided,
     however, a Material Adverse Change shall not include (i) adverse general
     economic conditions, (ii) adverse general industry conditions in the
     industry in which the Company operates or (iii) of itself: (x) a decline in
     the Company s stock price, (y) failure to achieve any projection or (z)
     failure to be awarded any particular contract. The Company shall provide
     prompt written notice of the occurrence of Material Adverse Change (but in
     any event within five (5) business days thereof). In the event that a
     Holder provides written notice to the Company that such Holder believes
     that a Material Adverse Change has occurred (a "Material Adverse Change
     Notice"), such notice shall be binding upon the Company unless, within five
     (5) business days thereafter, the Board of Directors of the Company, based
     on its good faith business judgement and upon advice of an investment
     banking firm of national standing shall dispute the occurrence of such
     Material Adverse Change. If the Company shall so dispute the occurrence of
     a Material Adverse Change, it shall, within three (3) business days after
     notice of such dispute by a Holder, submit such dispute to an independent
     investment bank of national standing (acceptable to such Holder). The
     investment banking firm shall determine whether the





     Material Adverse Change has occurred, and notify the Company and Holder of
     such determination no later than ten (10) days after such submission. The
     investment bank s determination shall be deemed conclusive. In the event
     that the investment bank shall determine that a Material Adverse Change has
     occurred, then during the Restoration Period immediately following the
     resolution of such dispute the "Conversion Price" shall mean the lesser of
     (a) the Conversion Price determined in accordance with Section 2(f) or (b)
     the lowest Conversion Price that would have been available had there been
     no dispute by the Company as to the existence of a Material Adverse Charge.
     The term "Restoration Period" means a number of business days during which
     there exists such a dispute as to the existence of a Material Adverse
     Change. An Operating Expense Reduction Failure shall mean the failure of
     the Company to announce, by filing of a Current Report on Form 8-K by June
     15, 1999, a bona fide and credible plan, adopted by the Board of Directors
     of the Company in its good faith business judgment, which reasonably
     provides for the reduction of operating expenses of the Company by $10
     million over a twelve (12) month period (before giving effect to any
     acquisitions) and which is implemented within thirty (30) days of such
     announcement.

               (d) Cap Debenture Election. In addition to the foregoing
     limitations, the Company may, upon written irrevocable notice to all
     Holders within ten (10) days of a Triggering Event (as defined below),
     elect (a "Cap Debenture Election") to exchange the Excess Debentures (as
     defined herein) for a twelve-month subordinated note of the Company having
     a face amount equal to such Excess Debentures plus accrued and unpaid
     interest thereon, which note shall bear interest at twelve percent (12%)
     per annum and contain such other terms and conditions as are reasonably
     requested and reasonably acceptable to Holder (a "Cap Debenture"). Such
     notice shall serve as binding and irrevocable notice of the Company's
     election to exercise the Cap Debenture Election as to all Holders, and the
     Company shall, within five (5) business days after such election,
     thereafter exchange the Excess Debentures for a Cap Debenture (but not as
     to any Holder prior to the occurrence of a Triggering Event as to such
     Holder). For purposes hereof, the "Excess Debentures" means that portion of
     the Debentures which, following actual submission of a Notice of Conversion
     by a Holder would, if converted in accordance with the terms hereof (other
     than this paragraph (d)), would result in such Holder beneficially owning
     in excess of such Holder's Cap Portion (as defined below). For any Holder,
     the "Cap Portion" means such Holder's pro rata share of twenty percent
     (20%) of the number of outstanding shares of Common Stock at the time of
     the Closing, based on such Holder's initial investment in the Debentures
     issued at the Closing.

          For purposes hereof, a "Triggering Event" shall be deemed to have
     occurred following actual submission of a Notice of Conversion by a Holder
     if the Company shall not have breached any representation, warranty,
     covenant or agreement made pursuant to the Investment Agreements, no Event
     of Failure (or event which, with notice, passage of time and/or
     continuation, would constitute an Event of Failure) has occurred and is
     continuing, and the Company has met the Solvency Condition (as defined
     below) and the number of shares of Class A Common Stock (the "Closing
     Shares") issued to such Holder upon conversion of the Debentures would, but
     for the Company making a Cap Debenture Election and the issuance of the Cap
     Debentures, equal or exceed such Holder's Cap Portion. Solvency Conditions
     means that the Company shall be in such financial condition as contemplated
     by the Solvency Certificate issued in connection with the issuance of the
     Debentures, as if however, the Solvency Certificate were addressing the
     issuance of the Cap Debentures as of the date of the Cap Debenture Election
     including, without limitation, the ability to so pay such Cap Debentures,
     and taking account of then current projections of the Company; and the
     Company shall have issued a new Solvency Certificate to such effect as of
     the date of the Cap Debenture Election.

          The limitations contained in this paragraph (d) shall apply on a
     Holder-by-Holder basis with respect to Debentures issued to such Holder at





     the  Closing, and  any transferee Holder  shall be  subject to  a pro rata
     portion of such limitation.

          3.8  Intentionally omitted.

          3.9 Electronic Transmission. In lieu of delivering physical
     certificates representing the Common Stock issuable upon conversion,
     provided the Borrower's escrow agent is participating in the Depository
     Trust Company ("DTC") Fast Automated Securities Transfer program (the
      FAST Program ), upon request of a Holder, the Borrower shall use its
     reasonable best efforts to cause its escrow agent to electronically
     transmit the Common Stock issuable upon conversion to the Holder by
     crediting the account of Holder's prime broker with DTC through its Deposit
     Withdrawal Agent Commission system. The Borrower shall use its reasonable
     best efforts to participate in the FAST Program.

                                   ARTICLE IV
                      RESERVATION OF SHARES OF COMMON STOCK

          4.1 Reserved Amount. At the Issue Date and thereafter, the Company
     shall have authorized and reserved and keep available for issuance not less
     than 8,500,000 (subject to equitable adjustment for any stock splits, stock
     dividends, reclassification or similar events and subject to reduction for
     the number of any shares of Class A Common Stock issued upon conversion of
     the Convertible Securities and upon exercise of the Warrants) shares of
     Class A Common Stock (the "Reserved Amount") solely for the purpose of
     effecting the conversion of the Convertible Securities and the exercise of
     the Warrants. The Company shall at all times reserve and keep available out
     of its authorized but unissued shares of Class A Common Stock the Reserved
     Amount. The Reserved Amount shall be allocated among the Holders as
     provided in Section 10.1 hereof. Notwithstanding anything contained herein,
     the Reserved Amount shall at no time exceed the Cap Amount; so long as the
     Reserved Amount is greater than the Cap Amount, the Reserved Amount shall
     equal the Cap Amount.

          4.2 Increases to Reserved Amount. Without limiting any other provision
     of this Article IV, if a Holder's allocable portion of the Reserved Amount
     for any three (3) consecutive trading days (the last of such three (3)
     trading days being the "Authorization Trigger Date") shall be less than one
     hundred seventy five percent (175%) of the number of shares of Class A
     Common Stock issuable upon conversion of such Holder's Debenture and 100%
     of the number of shares of Class A Common Stock issuable upon exercise of
     such Holder's Warrants on such trading days (in each case without giving
     effect to any limitation on conversion or exercise thereof), the Company
     shall immediately notify all Holders of such occurrence and shall take
     action as soon as possible, but in any event within sixty (60) days after
     an Authorization Trigger Date (including, if necessary, shareholder
     approval to authorize the issuance of additional shares of Class A Common
     Stock), to increase the Reserved Amount so that each Holder's allocable
     portion thereof shall equal or exceed two hundred percent (200%) of the
     number of shares of Class A Common Stock then issuable upon conversion of
     such Holder's Debenture and 100% of the number of shares of Class A Common
     Stock issuable upon exercise of such Holder's Warrants (in each case
     without giving effect to any limitation on conversion or exercise thereof).

                                    ARTICLE V
                     COMPLIANCE WITH CAP AMOUNT RESTRICTIONS

          Obligation to Notify. If at any time after the Issue Date the then
     unissued portion of any Holder s Cap Amount is less than one hundred
     seventy-five percent (175%) of the number of shares of Class A Common Stock
     then issuable upon conversion of such Holder s Debentures and exercise of
     such Holder s Warrants (in each case without giving effect to any
     limitation on conversion or exercise thereof), the Company shall
     immediately notify all Holders of such occurrence.





                                   ARTICLE VI
                         FAILURE TO SATISFY CONVERSIONS

          6.1 Conversion Default Payments. If, at any time, (x) a Holder submits
     a Notice of Conversion and the Company fails for any reason (other than to
     the extent (but only to the extent) that such failure is as a result of a
     dispute as to the occurrence of a Material Adverse Change as to which the
     provisions of Section 3.7(c) shall apply) to deliver, on or prior to the
     expiration of the Delivery Period for such conversion, such number of
     shares of Class A Common Stock to which such Holder is entitled upon such
     conversion, or (y) the Company provides notice (including by way of public
     announcement) to any Holder at any time of its intention not to issue
     shares of Class A Common Stock upon exercise by any Holder of its
     conversion rights in accordance with the terms of the Debentures (each of
     (x) and (y) being a "Conversion Default"), then the Company shall pay to
     such Holder damages in an amount equal to the product of (A) the Damages
     Amount times (B) D times (C) .01, where:

          "D" means, with respect to clause (x), the number of days beginning
     and including the day after the date of the Conversion Default through and
     including the Cure Date with respect to such Conversion Default, and with
     respect to clause (y), the number of days beginning and including the date
     of the Conversion Default through and including the Cure Date with respect
     to such Conversion Default

          "Damages Amount" means the Conversion Amount with respect to which
     such Conversion Default occurred (all outstanding principal amount of
     Debentures in the case of clause (y)) plus all accrued and unpaid interest
     thereon as of the first day of the Conversion Default.

          "Cure Date" means (i) with respect to a Conversion Default described
     in clause (x) of its definition, the date the Company effects the
     conversion of the portion of this Debenture submitted for conversion and
     (ii) with respect to a Conversion Default described in clause (y) of its
     definition, the date the Company undertakes in writing to issue Class A
     Common Stock in satisfaction of all conversions of Debentures in accordance
     with their terms.

          The payments to which a Holder shall be entitled pursuant to this
     Section 6.1 are referred to herein as "Conversion Default Payments." All
     Conversion Default Payments shall be paid in cash within five (5) business
     days of a Holder's demand therefore (which demand may be made at any time
     and from time to time).

          6.2 Buy-In Cure. If (i) the Company fails for any reason to deliver
     during the Delivery Period shares of Class A Common Stock to a Holder upon
     a conversion of this Debenture and (ii) after the applicable Delivery
     Period with respect to such conversion, a Holder purchases (a "Buy-In") (in
     an open market transaction or otherwise) shares of Class A Common Stock to
     make delivery upon a sale by a Holder of the shares of Class A Common Stock
     (the "Sold Shares") which such Holder anticipated receiving upon such
     conversion, the Company shall pay such Holder (in addition to any other
     remedies available to Holder) the amount by which (x) such Holder's total
     purchase price (including brokerage commission, if any) for the shares of
     Class A Common Stock so purchased exceeds (y) the net proceeds received by
     such Holder from the sale of the Sold Shares. For example, if a Holder
     purchases shares of Class A Common Stock having a total purchase price of
     $11,000 to cover a Buy-In with respect to shares of Class A Common Stock
     sold for $10,000, the Company will be required to pay such Holder $1,000. A
     Holder shall provide the Company written notification indicating any
     amounts payable to Holder pursuant to this Section 6.2.

          6.3 Adjustment to Conversion Price. If a Holder has not received
     certificates for all shares of Class A Common Stock within two business
     days following the expiration of the Delivery Period with respect to a





     conversion of any portion of any of such Holder's Debentures, then the
     Variable Conversion Price shall, with respect to such conversion and
     thereafter, be the lesser of (i) the Variable Conversion Price on the
     Conversion Date specified in the Notice of Conversion which resulted in the
     Conversion Default and (ii) the lowest Conversion Price in effect during
     the period beginning on, and including, such Conversion Date through and
     including the Cure Date. If there shall occur a Conversion Default of the
     type described in clause (y) of Section 6.1 hereof, then the Variable
     Conversion Price with respect to any conversion thereafter shall be the
     lower of the Variable Conversion Price and the lowest Conversion Price in
     effect at any time during the period beginning on, and including, the date
     of the occurrence of such Conversion Default through and including the Cure
     Date. Simultaneously with any reduction of the Variable Conversion Price
     pursuant to this Section 6.3, the Green Floor shall be reduced
     proportionately. For purposes of this Section, the Conversion Price shall
     include the Market Conversion Price whether or not the Market Conversion
     Price is otherwise applicable. The Variable Conversion Price shall
     thereafter be subject to further adjustment as provided in this Debenture
     (including by virtue of re-application of this Section 6.3), but shall not
     be subject to upward adjustment.

                                   ARTICLE VII
                                EVENTS OF FAILURE

          7.1 Holder s Option to Demand Redemption. Upon the occurrence of an
     Event of Failure, each Holder shall have the right to elect at any time and
     from time to time to have all or any portion of such Holder s then
     outstanding Debentures prepaid by the Company for an amount equal to the
     Holder Demand Redemption Amount (as herein defined).

               (a) The right of a Holder to elect prepayment shall be
     exercisable upon the occurrence of an Event of Failure by such Holder in
     its sole discretion by delivery of a Demand Redemption Notice (as herein
     defined) in accordance with the procedures set forth in this Article 7.
     Notwithstanding the exercise of such right, the Holder shall be entitled to
     exercise all other rights and remedies available under the provisions of
     this Debenture and at law or in equity.

               (b) A Holder shall effect each demand for prepayment under this
     Article VII by giving at least two (2) business days prior written notice
     (the "Demand Redemption Notice") of the date on which such prepayment is to
     become effective (the Effective Date of Demand of Redemption ), the
     Debentures selected for prepayment and the Holder Demand Redemption Amount
     to the Borrower at the address and facsimile number provided in Section
     10.2, which Demand Redemption Notice shall be deemed to have been delivered
     on the business day after the date of transmission of Holder's fax (with a
     copy sent by overnight courier to the Borrower) of such notice.

               (c) The Holder Demand Redemption Amount shall be paid to a Holder
     whose Debentures are being prepaid within one (1) business day following
     the Effective Date of Demand of Redemption.

               (d) Promptly following the date on which the Debentures are
     prepaid, Holder shall (i) deliver such Debentures to the office of the
     Borrower or the transfer agent or notify the Borrower or the transfer agent
     that such Debentures have been lost, stolen or destroyed and (ii) deliver
     the documentation required in accordance with Section 10.10 hereof.

          7.2 Holder Demand Redemption Amount. The Holder Demand Redemption
     Amount means (a) in the case of any Event of Failure provided in clauses
     (i), (m), (n), (o), (p) and (r) of Section 7.3 or a default in the cash
     payment of principal or interest due hereunder (a "Lesser Failure"), 1.15
     times the aggregate principal amount of the Debenture for which demand is
     being made (the "Stated Value"), plus all accrued and unpaid interest





     thereon through the date of prepayment and (b) in the case of an Event of
     Failure other than a Lesser Failure (a "Greater Failure"), the greater of:
     (i) 1.35 times the Stated Value plus all accrued and unpaid interest
     thereon through the date of prepayment and (ii) the product of (A) the
     highest price at which the Class A Common Stock is traded from the date of
     the Event of Failure through the date of the Effective Date of Demand of
     Redemption (or the most recent highest closing sale price if the Class A
     Common Stock is not traded between such dates) divided by the lowest
     Conversion Price during such period (assuming for these purposes that the
     Market Conversion Price is in effect, regardless of whether it is not
     actually in effect), and (B) the sum of the Stated Value plus all accrued
     and unpaid interest thereon through the date of prepayment. The Holder
     Demand Redemption Amount shall be reduced by the amount of any Default
     Alternative Payments made in respect of this Debenture pursuant to Section
     7.5 (but shall not apply principal except to the extent such Default
     Alternative Payments exceed 35% of the principal amount upon which such
     Default Alternative Payments were based).

          7.3 Events of Failure. An Event of Failure means any one of the
     following:

               (a) a Conversion Default described in Section 6.1 hereof occurs
     and is not cured by the Company within three (3) business days after its
     occurrence;

               (b) the Company fails, and such failure continues uncured for six
     (6) business days after the Company has been notified thereof in writing by
     a Holder, to satisfy the requirements of Section 4.1 hereof;

               (c) subject to any Permitted Blackout (as defined in the
     Registration Rights Agreement), the Registration Statement required to be
     filed by the Company pursuant to the Registration Rights Agreement, has not
     been filed within thirty (30) business days of the Closing or has not been
     declared effective by the two hundred and seventieth (270th) day following
     the Closing or such Registration Statement, after being declared effective,
     cannot be utilized by the Holders of Debentures and the Warrants for the
     resale of all of their Registrable Securities (as defined in the
     Registration Rights Agreement) for a period of five (5) consecutive
     business days or for an aggregate of more than ten (10) days in any twelve
     (12) month period;

               (d) the Class A Common Stock (or any portion thereof) is
     suspended from trading on any of, or is not listed (and authorized) for
     trading on any of, The Nasdaq National Market or the New York Stock
     Exchange for an aggregate of five (5) trading days in any nine (9) month
     period;

               (e) the Company fails, and any such failure continues uncured for
     ten (10) days after the Company has been notified thereof in writing by the
     Holder, to remove any restrictive legend on any certificate or any shares
     of Class A Common Stock issued to the Holders of Debentures or Warrants
     upon conversion of the Debentures or exercise of the Warrants (as the case
     may be);

               (f) the Company breaches, and such breach continues uncured for
     ten (10) business days after the Company has been notified thereof in
     writing by a Holder, any material covenant or other material term or
     condition of this Debenture, the Warrants, the Securities Purchase
     Agreement, the Security Agreement or the Registration Rights Agreement,
     including, without limitation, any default in payment of principal,
     interest or other amounts due hereunder or under the Registration Rights
     Agreement;

               (g) any representation or warranty of the Company made herein or
     in any agreement, statement or certificate given in writing pursuant hereto
     or in connection herewith (including, without limitation, this





     Debenture, the  Warrants, the Securities Purchase  Agreement, the Security
     Agreement and  the  Registration  Rights  Agreement), shall  be  false  or
     misleading in any material respect when made;

               (h) the Company fails to increase the Reserved Amount in
     accordance with Section 4.2 hereof;

               (i)  a Bankruptcy Event occurs;

               (j) the Company provides notice to any Holder, including by way
     of public announcement, at any time, of its intention not to issue shares
     of Class A Common Stock to any Holder upon conversion in accordance with
     the terms of the Debentures (other than because such issuance would exceed
     such Holder's allocated portion of the Cap Amount);

               (k) the Company's execution or performance of its obligations
     under this Debenture, the Warrants, the Securities Purchase Agreement or
     the Registration Rights Agreement (the "Documents") constitutes a breach
     under any existing agreement of the Company (or would cause a default or
     acceleration (or right of acceleration) under such existing agreement), or
     the Company enters into any new agreement under which performance of any
     material obligation under the Documents would be a breach or cause a
     default or acceleration (or right of acceleration) under such new
     agreement;
               (l) the Company fails to obtain the effectiveness of any
     amendment to an existing registration statement within five (5) days or of
     any new registration statement within ten (10) days as required by the
     Registration Rights Agreement;

               (m) an Event of Default (as defined in the Loan Agreement)
     (without giving effect to any waiver or indulgence by the lender which
     materially increases the amount required to be paid under the Loan
     Agreement as of the date of this Debenture), occurs or an acceleration
     occurs under the Loan Agreement;

               (n) The Company or any of its subsidiaries (i) defaults in the
     payment of principal or interest on any other indebtedness of five hundred
     thousand dollars ($500,000) or more beyond the applicable period of grace,
     if any, or (ii) fails to observe or perform any covenant or agreement
     contained in any agreement(s) or instrument(s) relating to any other
     indebtedness of five hundred thousand dollars ($500,000) or more in the
     aggregate within any applicable grace period, or any other event shall
     occur, if the effect of such failure or other event is to cause the
     acceleration of the maturity of five hundred thousand dollars ($500,000) or
     more in the aggregate of such indebtedness; or five hundred thousand
     dollars ($500,000) or more in the aggregate of any indebtedness is required
     to be prepaid (other than by regularly scheduled required prepayment) in
     whole or in part prior to its stated maturity;

               (o) The Company receives from its independent certified
     accounting firm in connection with its audited financial statements a
     "going concern" qualification or exception;

               (p) a judgment which, together with other undischarged judgments
     against the Company, is in excess of five hundred thousand dollars
     ($500,000) is rendered against the Company and, within sixty (60) days
     after entry thereof, such judgment is not discharged or execution thereof
     is not stayed pending appeal, or within sixty (60) days after the
     expiration of such stay, such judgment is not discharged;

               (q) the Shareholder Approval required to be obtained by the
     Company is not effective by September 30, 1999; or

               (r) an event of default under the Cap Debentures occurs.

          7.4  Failure  to Pay Damages Amount. The Company shall pay the Holder





     Demand Redemption Amount within five (5) days of receipt of a written
     request therefor by a Holder. In the event the Company is not able to pay
     all amounts due and payable with respect to all Debentures subject to
     Holder Demand Redemption Notices, the Company shall pay the Holders such
     amounts pro rata, based on the total amounts payable to such Holder
     relative to the total amounts payable to all Holders. During the
     continuance of an Event of Failure (the "Failure Period"), the Conversion
     Price shall mean the lowest Conversion Price at any time during the Failure
     Period (notwithstanding the actual Conversion Date) determined in
     accordance with the foregoing provisions of the definition (but assuming
     that for these purposes that the Market Conversion Price is in effect,
     regardless of whether it is not actually in effect).

          7.5 Default Alternative. Upon the occurrence of a Greater Failure, a
     Holder may elect by written notice to the Company (a "Default Alternative
     Election") to forebear from requiring a prepayment of this Debenture
     pursuant to Section 7.1 and to receive cash payments from the Company, and
     if the Holder makes such election the Company shall pay to the Holder, in
     an amount per day equal to one (1%) percent of the outstanding principal
     amount of the Debenture, not to exceed one hundred thirty five percent
     (135%) of such outstanding amount ("Default Alternative Payment"). The
     delivery by a Holder of a Default Alternative Election in connection with
     an Event of Failure shall not preclude such Holder from subsequently
     exercising its rights under Section 7.1 in connection with such Event of
     Failure and any prior or subsequent Event of Failure. Payments may also be
     made under this Section 7.5 with respect to Lesser Failures up to an
     aggregate of one hundred fifteen percent (115%) of such outstanding amount
     (also a "Default Alternative Payment") as contemplated by the Subordination
     Agreement.

                                  ARTICLE VIII
                       ADJUSTMENTS TO THE CONVERSION PRICE

          The Conversion Price shall be subject to adjustment from time to time
     as follows:

          8.1 Stock Splits, Stock Dividends, Etc. If at any time on or after the
     date of issuance of this Debenture, the number of outstanding shares of
     Class A Common Stock is increased by a stock split, stock dividend,
     combination, reclassification or other similar event, the Variable
     Conversion Price, the Market Conversion Price and the Green Floor Price
     shall each be proportionately reduced, or if the number of outstanding
     shares of Class A Common Stock is decreased by a reverse stock split,
     combination or reclassification of shares, or other similar event, the
     Variable Conversion Price, the Market Conversion Price and the Green Floor
     Price shall each be proportionately increased. In such event, the Company
     shall notify the Company's transfer agent of such change on or before the
     effective date thereof.

          8.2 Certain Public Announcements. In the event that (i) the Company
     makes a public announcement that it intends to consolidate or merge with
     any other entity (other than a merger in which the Company is the surviving
     or continuing entity and its capital stock is unchanged and there is no
     distribution thereof) or to sell or transfer all or substantially all of
     the assets of the Company or (ii) any person, group or entity (including
     the Company) publicly announces a tender offer in connection with which
     such person, group or entity seeks to purchase 50% or more of the Common
     Stock (the date of the announcement referred to in clause (i) or (ii) of
     this paragraph is hereinafter referred to as the "Announcement Date"), then
     the Conversion Price shall, effective upon the Announcement Date and
     continuing through the consummation of the proposed tender offer or
     transaction or the Abandonment Date (as defined below) or thirty (30) days
     after announcement, whichever is sooner, be equal to the lesser of (x) the
     Conversion Price calculated as provided in Article II hereof and (y) the
     Conversion Price which would have otherwise have been applicable for
     Conversion occurring on the Announcement Date. From and





     after the Abandonment Date or the thirtieth (30th) day after announcement,
     as the case may be, the Conversion Price shall be determined as set forth
     in Article II hereof. The "Abandonment Date" means with respect to any
     proposed transaction or tender offer for which a public announcement as
     contemplated by this paragraph has been made, the date which is seven (7)
     trading days after the date upon which the Company (in the case of clause
     (i) above) or the person, group or entity (in the case of clause (ii)
     above) publicly announces the termination or abandonment of the proposed
     transaction or tender offer which causes this paragraph to become
     operative.

          8.3 Major Transactions. If the Company shall consolidate or merge with
     any other corporation or entity (other than a merger in which the Company
     is the surviving or continuing entity and its capital stock is unchanged
     and unissued in such transaction (except for issuances which do not exceed
     20% of the Class A Common Stock and do not result in a Change of Control))
     or there shall occur any share exchange pursuant to which all of the
     outstanding shares of Common Stock are converted into other securities or
     property or any reclassification or change of the outstanding shares of
     Common Stock or the Company shall sell all or substantially all of its
     assets or there shall occur a Change of Control (each of the foregoing
     being a "Major Transaction"), then each Holder shall thereafter be entitled
     to receive consideration, in exchange for such Debenture, equal to the
     greater of, as determined in the sole discretion of such Holder: (i) if
     applicable, the number of shares of stock or securities or property of the
     Company, or of the entity resulting from such Major Transaction (the "Major
     Transaction Consideration"), to which a holder of the number of shares of
     Class A Common Stock delivered upon conversion of such Debenture would have
     been entitled upon such Major Transaction had the Holder of such Debenture
     exercised its right of conversion (without regard to any limitations on
     conversion herein or elsewhere contained) on the trading date immediately
     preceding the public announcement of the transaction resulting in such
     Major Transaction and had such Class A Common Stock been issued and
     outstanding and had such Holder been the holder of record of such Class A
     Common Stock at the time of the consummation of such Major Transaction and
     (ii) one hundred twenty five percent (125%) of the principal amount of this
     Debenture in cash; and the Company shall make lawful provision therefor as
     a part of such Major Transaction and shall cause the issuer of any security
     in such transaction which constitutes Registrable Securities under the
     Registration Rights Agreement to assume all of the Company obligations
     (provided any cash election pursuant to clause (ii) above must be made in
     writing to the Company within ten (10) business days following consummation
     of such applicable transaction (or, in the event that a Company Transaction
     (as defined below) occurs, within ten (10) business days following the
     Measurement Period (as defined below)). In the event that the Company shall
     merge with any other corporation in a transaction in which common stock of
     the surviving corporation or the parent thereof (the "Exchange Securities")
     is issued to the holders of Class A Common Stock in such transaction in
     exchange for all such Class A Common Stock, and (a) the Exchange Securities
     are publicly traded, (b) the average daily trading volume of the Exchange
     Securities during the one hundred eighty (180) day period ending on the
     date on which such transaction is publicly disclosed is greater than two
     million dollars ($2,000,000), (c) the historical one hundred (100) day
     volatility of the Exchange Securities during the period ending on the date
     on which such transaction is publicly disclosed is greater than sixty
     percent (60%), and (d) the market capitalization of the issuer of the
     Exchange Securities is not less than one hundred fifty million dollars
     ($150,000,000) based on the last sale price of the Exchange Securities on
     the date immediately before the date on which such transaction is publicly
     disclosed (in each case, with respect to the foregoing clauses (a) through
     (d), as reported by Bloomberg), then the provisions of clause (ii) of the
     preceding sentence shall not apply. In the event that the Company shall, in
     a Major Transaction, merge with any other corporation in a transaction in
     which the Company is the survivor (a "Company Transaction"), the provisions
     of clause (ii) of the second





     preceding sentence shall not apply to the extent that each of the following
     conditions remain true for the thirty (30) business days commencing as of
     the date of the consummation of such transaction (the "Measurement Period":
     (a) the Class A Common Stock remains publicly traded during the period, (b)
     the average daily trading volume of the Class A Common Stock is greater
     than two million dollars ($2,000,000), (c) the historical thirty (30) day
     volatility of the Company s Class A Common Stock is greater than sixty
     percent (60%), and (d) the market capitalization of the Company (including
     Class B Common Stock) is not less than one hundred fifty million dollars
     ($150,000,000) on the last day of the period (in each case, with respect to
     the foregoing clauses (a) through (d), as reported by Bloomberg). No sooner
     than ten (10) days nor later than five (5) days prior to the consummation
     of the Major Transaction, but not prior to the public announcement of such
     Major Transaction, the Company shall deliver written notice ("Notice of
     Major Transaction") to each Holder, which Notice of Major Transaction shall
     be deemed to have been delivered one (1) business day after the Company s
     sending such notice by telecopy (provided that the Company sends a
     confirming copy of such notice on the same day by overnight courier) of
     such Notice of Major Transaction. Such Notice of Major Transaction shall
     indicate the amount and type of the Major Transaction Consideration which
     such Holder would receive under clause (i) of this Section 8.3. If the
     Major Transaction Consideration which constitutes cash does not consist
     entirely of United States currency, such Holder may elect to receive United
     States currency in an amount equal to the value of the Major Transaction
     Consideration in lieu of the Major Transaction Consideration by delivering
     notice of such election to the Company within five (5) days of the Holder s
     receipt of the Notice of Major Transaction. As used in this Section 8.3, a
     "Change of Control" shall be deemed to have occurred at any time that the
     holders of Class B Common as of the date of the issuance of this Debenture
     no longer (x) have voting control of the Company s outstanding Common Stock
     or (y) have a material economic interest in the Company s equity.

          8.4 Adjustment Due to Distribution. If the Company shall declare or
     make any distribution of its assets (or rights to acquire its assets) to
     holders of Common Stock as a partial liquidating dividend, by way of return
     of capital or otherwise (including any dividend or distribution to the
     Company's shareholders in cash or shares (or rights to acquire shares) of
     capital stock of a subsidiary) (a "Distribution") at any time, then the
     Holder shall be entitled, upon any conversion of this Debenture after the
     date of record for determining shareholders entitled to such Distribution,
     to receive the amount of such assets (or rights) which would have been
     payable to the Holder had the Holder with respect to the shares of Common
     Stock issuable upon such conversion and the shares of Common Stock issuable
     upon exercise of the Warrants (in each case without regard to any
     limitations on conversion or exercise herein or elsewhere contained) been
     the holder of such shares of Common Stock on the record date for the
     determination of shareholders entitled to such Distribution.

          8.5 Issuance of Other Securities. If, at any time after the Closing
     Date the Company shall issue any securities which are convertible into or
     exchangeable for Common Stock ("Convertible Securities") either (i) at a
     conversion or exchange rate based on a discount from the market price of
     the Common Stock at the time of conversion or exercise or (ii) with a fixed
     conversion or exercise price less than the Variable Conversion Price, then,
     at the Holder's option: (x) in the case of clause (i), the Market
     Conversion Price, Variable Conversion Price and Green Floor Price in
     respect of any conversion of the Debentures after such issuance shall be
     calculated utilizing the greatest discount applicable to any such
     Convertible Securities; and (y) in the case of clause (ii), the Variable
     Conversion Price shall be reduced to such lesser conversion or exercise
     price and the Market Conversion Price and the Green Floor Price shall be
     proportionately reduced. If the Company shall issue any Convertible
     Securities that are convertible into or exchangeable for shares of Common
     Stock on a basis different from that of this Debenture, the Holder of this





     Debenture may elect that the provisions to this Debenture be revised to
     incorporate such different provisions with respect to conversion or
     exchange, subject to the limitations of Section 3.7 hereof..

          8.6 Purchase Rights. If the Company issues any Convertible Securities
     or rights to purchase stock, warrants, securities or other property (the
     "Purchase Rights") pro rata to the record holders of any class of Common
     Stock, then the Holders will be entitled to acquire, upon the terms
     applicable to such Purchase Rights, the aggregate Purchase Rights which
     each Holder could have acquired if such Holder had held the number of
     shares of Common Stock acquirable upon complete conversion of this
     Debenture (without regard to any limitations on conversion or exercise
     herein or elsewhere contained) immediately before the date on which a
     record is taken for the grant, issuance or sale of such Purchase Rights,
     or, if no such record is taken, the date as of which the record holders of
     Common Stock are to be determined for the grants, issue or sale of such
     Purchase Rights.

          8.7 Special Adjustment. If the Company takes any actions other than by
     virtue of other provisions of this Article VII (excluding (i) issuance of
     shares in the ordinary course of business pursuant to employee stock option
     plans or employee stock purchase plans in effect on the date hereof, (ii)
     issuance of equity securities for consideration other than cash pursuant to
     a bona fide merger, consolidation, acquisition or similar business
     combination and issuance of convertible securities, options or rights in
     exchange for equivalent outstanding instruments of the other business
     combination party, and (iii) if the Market Conversion Price is then the
     applicable Conversion Price, the issuance of Common Stock at then market
     price) which would have a dilutive effect on the Holder or which would
     materially and adversely affect the Holder with respect to its investment
     in the Debenture, and if the provisions of this Article VIII are not
     strictly applicable to such actions or, if applicable to such actions,
     would not operate to equitably protect the Holder against such actions,
     then the Company shall promptly upon notice from a Holder appoint its
     independent certified public accountants to determine as promptly as
     practicable an appropriate adjustment to the terms hereof, including
     without limitation adjustments to the Variable Conversion Price, the Market
     Conversion Price and the Green Floor Price, or another appropriate action
     to so equitably protect such Holder and prevent any such dilution and any
     such material adverse effect, as the case may be. Following such
     determination, the Company shall forthwith make the adjustments or take the
     other actions described therein. In addition, in the event an adjustment
     would be required pursuant to Section 4(a) and 4(b) of the Warrant then a
     proportionate adjustment shall be made with respect to the Variable
     Conversion Price and the Green Floor Price hereunder.

          8.8 Notices of Adjustment. Upon the occurrence of each adjustment or
     readjustment pursuant to this Article VIII, the Company, at its expense,
     shall promptly compute such adjustment or readjustment and prepare and
     furnish to each Holder a certificate setting forth such adjustment or
     readjustment and showing in detail the facts upon which such adjustment or
     readjustment is based. The Company shall, upon the written request at any
     time of any Holder, furnish to such Holder a like certificate setting forth
     (i) such adjustment or readjustment, (ii) the Conversion Price at the time
     in effect and (iii) the number of shares of Common Stock and the amount, if
     any, of other securities or property which at the time would be received
     upon conversion of a Debenture.

          8.9 Delisting. In the event that the Common Stock of the Company is
     suspended from trading or is no longer listed (and authorized) for trading
     on The Nasdaq National Market or the New York Stock Exchange, the
     Conversion Price shall be reduced by ten (10%) percent of that amount
     calculated pursuant to Article II hereof and the Market Conversion Price
     shall be available for use by a Holder regardless of any other provision
     hereof. The Company shall also be required to pay to the Holders an amount
     (the "Delisting Amount") equal to the product of (i) 1.25 percent





     times (ii) the outstanding principal amount of this Debenture on the date
     such suspension or delisting goes into effect plus all accrued and unpaid
     interest thereon. Such Delisting Amount shall be due and payable to the
     Holders for each monthly period that the Common Stock of the Company
     remains suspended from trading or is no longer listed (and authorized) as
     specified herein.

          8.10 If any Executive Officer or Director (as defined below), during
     the period beginning on the date of the Closing and ending on the date that
     is six (6) months after the registration statement required pursuant to
     Section 2.1 of the Registration Rights Agreement is declared effective, and
     while an officer or director, directly or indirectly, offers, sells,
     transfers, assigns, pledges, or otherwise disposes of any shares of Common
     Stock, or any securities directly or indirectly convertible into or
     exercisable or exchangeable for, or warrants, options or rights to purchase
     or acquire shares of Common Stock (all such securities,
      Options ) or enter into any agreement, contract, arrangement or
     understanding with respect to any such offer, sale, transfer, assignment,
     pledge or other disposition of any Common Stock or Options (an "Executive
     Transfer"), then the Conversion Price shall be reduced by twenty percent
     (20%) of that amount calculated pursuant to Article II hereof and the
     Market Conversion Price shall be available for use by a Holder regardless
     of any other provision hereof; provided, however that an Executive Officer
     or Director may sell up to ten percent (10%) of his or her total holdings,
     calculated as of the date of the Closing, during such six-month period
     without triggering the adjustments of this Section 8.10. For purposes of
     this Section 8.10, Executive Officer or Director shall mean Marc Zionts, J.
     William Nelson, Stephen J. Hawrysz, Richard P. Reviere, Marc Hafner,
     William Noll, John Seazholtz, Paul Dwyer, Ormand Wade, Melvin Simon, Robert
     C. Penney III and Robert Gaynor and any individual hired by the Company
     after the date of this Debenture to assume the duties of any of the
     foregoing individuals.

                                   ARTICLE IX
                           RANK; PROTECTION PROVISIONS

          9.1 Participation. Each Holder shall, as a Holder of a Debenture, be
     entitled to dividends paid and distributions made to the holders of Common
     Stock to the same extent as if such Holder had fully converted the
     Debenture held by such Holder on the record date for such dividends or
     distributions into Common Stock (without regard to any limitations on
     conversion herein or elsewhere contained) at the Conversion Price
     applicable on such record date and such Common Stock had been issued on the
     day before such record date. Payments under the preceding sentence shall be
     made concurrently with the dividend or distribution to the holders of
     Common Stock.

          9.2 Protection Provisions. The Company shall not, without first
     obtaining the approval of the Majority Holders and, to the extent their
     interests may be adversely affected, each initial Holder of Debentures: (i)
     alter or change the rights, preferences or privileges of any capital stock
     of the Company so as to affect adversely the Debentures; (ii) redeem, or
     declare or pay any cash dividend or distribution on, any securities of the
     Company ranking on liquidation junior to the Debentures; or (iii) do any
     act or thing not authorized or contemplated by this Debenture which would
     result in any taxation with respect to the Debentures under Section 305 of
     the Internal Revenue Code of 1986, as amended, or any comparable provision
     of the Internal Revenue Code as hereafter from time to time amended (or
     otherwise suffer to exist any taxation as a result thereof).

                                    ARTICLE X
                                  MISCELLANEOUS

          10.1 Allocation of Cap Amount and Reserved Amount. The initial Cap
     Amount and Reserve Amount shall be allocated pro rata among the Holders





     based on the number of Debentures and Warrants held by each Holder. Each
     increase to the Cap Amount or Reserved Amount shall be allocated pro rata
     among the Holders based on the number of Debentures and Warrants held by
     each Holder at the time of increase in the Cap Amount or the Reserved
     Amount, as the case may be. In the event a Holder shall sell or otherwise
     transfer any of such Holder s Debentures or Warrants, each transferee shall
     be allocated a pro rata portion of such transferor s Cap Amount and
     Reserved Amount. Any portion of the Cap Amount or Reserved Amount which
     remains allocated to any person or entity which does not hold any
     Debentures or Warrants shall be allocated to the remaining Holders, pro
     rata based on the number of Debentures and Warrants then held by such
     Holders.

          10.2 Payment of Cash; Defaults. Whenever the Company is required to
     make any cash payment to a Holder under this Debenture (as a Conversion
     Default Payment, Holder Demand Redemption Amount or otherwise), such cash
     payment shall be made to the Holder by the method (by certified or
     cashier's check or wire transfer of immediately available funds) elected by
     such Holder. If such payment is not delivered when due (any such amount not
     paid when due being a Default Amount ) such Holder shall thereafter be
     entitled to interest on the unpaid amount at a per annum rate equal to the
     lower of fifteen percent (15%) or the highest interest rate permitted by
     applicable law until such amount is paid in full to the Holder. In
     addition, and notwithstanding anything to the contrary contained in this
     Debenture, a Holder may elect in writing to convert all or any portion of
     accrued Default Amounts, at any time and from time to time, into Common
     Stock at the lowest Conversion Price in effect during the period beginning
     on the date of the default with respect thereto through the cure date for
     such default. In the event that a Holder elects to convert all or any
     portion of the Default Amounts into Common Stock, the Holder shall so
     notify the Company on a Notice of Conversion of such portion of the Default
     Amounts which such Holder elects to so convert and such conversion shall be
     effected in accordance with the provisions of, and subject to limitations
     contained in, Article III hereof.

          10.3 Failure or Indulgence Not Waiver. No failure or delay on the part
     of a Holder in the exercise of any power, right or privilege hereunder
     shall operate as a waiver thereof, nor shall any single or partial exercise
     of any such power, right or privilege preclude other or further exercise
     thereof or of any other right, power or privilege.

          10.4 Notice. Any notice herein required or permitted to be given shall
     be in writing and may be personally served or delivered by courier or by
     confirmed telecopy and shall be deemed to have been given at the time and
     date of receipt (which shall include telephone line facsimile
     transmission). The addresses for such communications shall be:
                    If to the Company:

                    Westell Technologies, Inc.
                    750 N. Commons Drive
                    Aurora, IL 60504
                    Telecopy: (630) 375-4940
                    Attention: Stephen J. Hawrysz

                    with a copy to:

                    Neal J. White, P.C.
                    McDermott, Will & Emery
                    227 West Monroe Street
                    Chicago, IL 60606
                    Telecopy:  (312) 984-3669

                    If to Holder:

                    [INSERT]





                    and with a copy to:

                    [INSERT]

          If to any other Holder, to such address set forth under Holder's name
     on the signature page of the Securities Purchase Agreement executed by such
     Holder.

          10.5 Amendment Provision. Except as provided in Section 3.7(b) hereof,
     this Debenture and any provision hereof may only be amended by an
     instrument in writing signed by the Company and the Majority Holders. The
     term "Debenture" and all references thereto, as used throughout this
     instrument, shall mean this instrument as originally executed, or if later
     amended or supplemented, then as so amended or supplemented.

          10.6 Assignability. This Debenture shall be binding upon the Company
     and its successors and assigns and shall inure to the benefit of each
     Holder and its successors and assigns. The Holder shall notify the Company
     upon the assignment of this Debenture.

          10.7 Cost of Collection. If default or failure is made in any manner
     with respect to this Debenture, the Company shall pay the Holder hereof
     costs of collection, including reasonable attorneys' fees.

          10.8 Governing Law. This Debenture shall be governed by and construed
     in accordance with the laws of the State of New York applicable to
     contracts made and to be performed in the State of New York. The Company
     irrevocably consents to the jurisdiction of the United States federal
     courts located in the State of New York in any suit or proceeding based on
     or arising under this Agreement and irrevocably agrees that all claims in
     respect of such suit or proceeding may be determined in such courts. The
     Company irrevocably waives the defense of an inconvenient forum to the
     maintenance of such suit or proceeding. The Company further agrees that
     service of process upon the Company, mailed by first class mail shall be
     deemed in every respect effective service of process upon the Company in
     any such suit or proceeding. Nothing herein shall affect each Holder's
     right to serve process in any other manner permitted by law. The Company
     agrees that a final non-appealable judgment in any such suit or proceeding
     shall be conclusive and may be enforced in other jurisdictions by suit on
     such judgment or in any other lawful manner.

          10.9 Denominations. At the request of a Holder, upon surrender of this
     Debenture, the Company shall promptly issue new Debentures in the aggregate
     outstanding principal amount hereof, in the form hereof, in such
     denominations as such Holder shall request.

          10.10 Lost or Stolen Debentures. Upon receipt by the Company of (i)
     evidence of the loss, theft, destruction or mutilation of this Debenture
     and (ii) (y) in the case of loss, theft or destruction, or an indemnity
     reasonably satisfactory to the Company, or (z) in the case of mutilation,
     upon surrender and cancellation of this Debenture, the Company shall
     execute and deliver new Debentures, in the form hereof, in such
     denominations as a Holder may request. However, the Company shall not be
     obligated to reissue such lost or stolen Debentures if such Holder
     contemporaneously requests the Company to convert this Debenture.

          10.11 Statements of Available Shares. Upon request, the Company shall
     deliver to a Holder a written report notifying such Holder of any
     occurrence which prohibits the Company from issuing Common Stock upon any
     such conversion. The report shall also specify (i) the total principal
     amount of all outstanding Debentures as of the date of the request, (ii)
     the total number or shares of Common Stock issued upon all conversions of
     Debentures through the date of the request, (iii) the total number of
     shares of Common Stock issued upon exercise of all Warrants through the
     date of the request, (iv) the total number of shares of Common Stock which
     are reserved for issuance upon conversion of Debentures and exercise of





     Warrants as of the date of the request and (v) the total number of shares
     of Common Stock which may thereafter be issued by the Company upon
     conversion of Debentures and exercise of Warrants before the Company would
     exceed the Cap Amount and Reserved Amount. The Company shall, within five
     (5) days after delivery to the Company of a written request by any Holder,
     provide all of the information enumerated in clauses (i) - (v) of this
     Section 10.11 and, at the request of a Holder, make public disclosure
     thereof.

          10.12 Status as Debenture Holder. Upon submission of a Notice of
     Conversion by Holder, the principal amount of this Debenture and the
     interest thereon covered thereby shall be deemed converted into shares of
     Class A Common Stock and the Holder's rights as a Holder of such converted
     Debenture with respect thereto shall cease and terminate, excepting only
     the right to receive certificates for such shares of Class A Common Stock
     and to any remedies provided herein or otherwise available at law or in
     equity to Holder because of a failure by the Company to comply with the
     terms of this Debenture. Notwithstanding the foregoing, if Holder has not
     received certificates for all shares of Class A Common Stock prior to the
     tenth (10th) business day after the expiration of the Delivery Period with
     respect to a conversion for any reason, then (unless Holder otherwise
     elects to retain its status as a Holder of Class A Common Stock) the
     portion of the principal amount and interest thereon subject to such
     conversion shall be deemed outstanding under this Debenture, the Holder
     shall regain the rights of a holder of a Debenture with respect to such
     unconverted Debentures and the Company shall, as soon as practicable,
     return such unconverted Debentures to the Holder. In all cases, the Holder
     shall retain all of its rights and remedies (including, without limitation,
     (i) the right to receive Conversion Default Payments pursuant to Section
     6.1 hereof to the extent required thereby for such Conversion Default and
     any subsequent Conversion Default and (ii) the right with respect to
     conversions in accordance with Section 10.2 hereof, to the extent
     applicable) for the Company's failure to convert this Debenture.

          10.13 Ratable Payments. All payments and prepayments made by the
     Company with respect to the Debentures as to which more than one Holder
     shall be entitled shall be made ratably among all such Holders of
     Debentures in accordance with the principal amount of such Debentures.

          10.14 Remedies, Characterizations, Other Obligations, Breaches and
     Injunctive Relief. The remedies provided in this Debenture shall be
     cumulative and in addition to all other remedies available under this
     Debenture, at law or in equity (including a decree of specific performance
     and/or other injunctive relief), no remedy contained herein shall be deemed
     a waiver of compliance with the provisions giving rise to such remedy and
     nothing herein shall limit a Holder's right to actual damages for any
     failure by the Company to comply with the terms of this Debenture
     (including, without limitation, damages incurred to effect "cover" of
     shares of Common Stock anticipated to be received upon a conversion
     hereunder but not received in accordance with the terms hereof). The
     Company covenants to each Holder that there shall be no characterization
     concerning this instrument other than as expressly provided herein. Amounts
     set forth or provided for herein with respect to payments, conversion and
     the like (and the computation thereof) shall be the amounts to be received
     by the Holder hereof and shall not, except as expressly provided herein, be
     subject to any other obligation of the Company (or the performance
     thereof). The Company acknowledges that a breach by it of its obligations
     hereunder will cause irreparable harm to the holders of the Debentures and
     that the remedy at law for any such breach may be inadequate. The Company
     therefore agrees that, in the event of any such breach or threatened
     breach, the Holders shall be entitled, in addition to all other available
     remedies, to an injunction restraining any breach, without the necessity of
     showing economic loss and without any bond or other security being
     required.

          10.15     Specific   Shall  Not  Limit  General;  Construction.    No





     specific provision contained in this Debenture shall limit or modify any
     more general provision contained herein. As used herein, the word
     "including" shall be deemed to mean "including, without limitation." This
     Debenture shall be deemed to be jointly drafted by the Company and all
     Holders and shall not be construed against any person as the drafter
     hereof.

                                        * * *


          IN WITNESS WHEREOF, Borrower has caused this Debenture to be signed in
     its name by its duly authorized officer as of the date first written above.


                                   WESTELL TECHNOLOGIES, INC.


                                   By: 
                                        ----------------------------------
                                      Name:
                                     Title:



                              NOTICE OF CONVERSION

     The undersigned hereby irrevocably elects to convert (the Conversion )
     $__________ principal amount of the Debenture plus all accrued and unpaid
     interest on such principal amount (i.e., $_________) plus all accrued and
     unpaid Conversion Default Payments relating thereto (if any) (each as
     defined in the Debenture dated ____________, 1999 (the "Debenture")), into
     shares of common stock ("Common Stock") of Westell Technologies, Inc. (the
     "Company") according to the conditions of the Debenture, as of the date
     written below. If securities are to be issued in the name of a person other
     than the undersigned, the undersigned will pay all transfer taxes payable
     with respect thereto. No fee will be charged to the Holder for any
     conversion except as provided herein.

     The undersigned represents and warrants that all offers and sales by the
     undersigned of the securities issuable to the undersigned upon conversion
     of this Debenture shall be made pursuant to registration of the Common
     Stock under the Securities Act of 1933, as amended (the "Act"), or pursuant
     to an exemption from registration under the Act.

     In the event of partial exercise, please reissue an appropriate
     Debenture(s) for the principal balance which shall not have been converted.

                                   Conversion Date:

                                   Applicable Conversion Price:

                                   Amount of Conversion Default Payments to be
                                   Converted, if any:

                                   Number of Shares of
                                   Class A Common Stock to be Issued:


                                   Signature:

                                      Name:

                                    Address:





     ACKNOWLEDGED AND AGREED:

     WESTELL TECHNOLOGIES, INC.

     By:                                                                       
        -----------------------------

     --------------------------------
     Name:                                                                     

     --------------------------------
     Title:                                                              Date: