Exhibit 10.5

                          JOINDER AND SECOND AMENDMENT
                                           TO LOAN AND SECURITY AGREEMENT


         This  Joinder  and  Second  Amendment  to Loan and  Security  Agreement
"Second  Amendment") entered into as of December 30, 1996 between Fleet Capital
Corporation,  f/k/a Shawmut Capital Corporation,  successor to Barclays Business
Credit,  Inc.  ("Lender"),  a Rhode  Island  corporation  with an  office at 200
Glastonbury  Boulevard,  Glastonbury,  CT 06033 and MasTec, Inc.  ("MasTec"),  a
Delaware corporation,  each other entity comprising the Telecommunication  Group
(as  defined in Appendix A to the Loan  Agreement);  and  Southeastern  Printing
Company, Inc. ("Southeastern  Printing"),  a Florida corporation;  (collectively
"Borrowers"  and singly  each is a  "Borrower"),  the  Sureties  (as  defined in
Appendix A to the Loan Agreement) each with its chief executive  office at Suite
110, 3155 N.W. 77th Avenue, Miami, Florida 33122-1205;  and Harrison-Wright Co.,
Inc.,  a  Delaware  corporation  ("HWC");  Utility  Precast,  Inc.,  a  Delaware
corporation  ("UPI"),  each with its chief executive  office at 305 South Church
Street,  Charlotte,  NC 28202  and  Carolina  Com-tec,  Inc.,  a North  Carolina
corporation ("CCI") with its chief executive office at 1715 Orr Industrial Park,
Charlotte, NC 28213.
                                                     BACKGROUND









         A.  Borrowers,  Sureties  and Lender are parties to a certain  Loan and
Security  Agreement  dated January 26, 1995, as amended by that certain  Joinder
and First  Amendment  to Loan and  Security  Agreement  dated  February 29, 1996
(collectively  "Loan Agreement")  pursuant to which Lender  established  certain
financing arrangements for the benefit of Borrowers.  The Loan Agreement and all
instruments,  documents  and  agreements  executed in connection  therewith,  or
related thereto are referred to herein collectively as the "Loan Documents".
         B.  MasTec and H-W  Liquidating  Company,  Inc.  (f/k/a  HarrisonWright
Company, Inc.), a North Carolina corporation,  and UPI Liquidating Company, Inc.
(f/k/a  Utility  Precast,  Inc.),  a North  Carolina  corporation  (collectively
"Sellers")  are  parties  to a  certain  Asset  Purchase  Agreement  dated as of
November  22,  1996,  and MasTec and the  shareholders  of CCI are  parties to a
certain Stock Purchase Agreement dated as of February 2, 1996 (collectively with
the Asset  Purchase  Agreement,  the  "Purchase  Agreements")  pursuant to which
MasTec  acquired all of the assets each of HWC and UPI and all of the issued and
outstanding common stock of CCI (collectively "Stock").
         C. In  recognition  of the  benefits  and  privileges  under  the  Loan
Documents,  HWC, UPI and CCI have  requested that they be permitted to join into
the Loan Documents as if original  signatories  thereto and Borrowers,  Sureties
and Lender have so consented subject to the terms and conditions hereof.
     D. In addition,  Borrowers have  requested  that Lender  increase the Total
Credit Facility. Lender has agreed to do so, subject to the terms and conditions
set forth below.
         NOW WHEREFORE, with the foregoing background incorporated by reference,
the parties hereto, intending to be legally bound, hereby agree as follows:
         1.       Joinder
                  1.1 Upon the effectiveness of this Second Amendment,  HWC, UPI
and CCI join in, assume,  adopt and become  Borrowers  under the Credit Facility
and all Loans.  All  references  to Borrower or Borrowers  contained in the Loan
Documents  (including this Second Amendment) are hereby deemed, for all purposes
to refer to and  include  HWC,  UPI and CCI as a Borrower  and HWC,  UPI and CCI
hereby  agree  to  comply  with  all of the  terms  and  conditions  of the Loan
Documents as if each were an original signatory thereto.
                  1.2 Without  limiting  the  generality  of the  provisions  of
subparagraph  1.1 above,  HWC,  UPI and CCI are thereby  liable,  on a joint and
several basis,  along with all other Borrowers and Sureties for all existing and
future Loans and other  liabilities and obligations  incurred at any time by any
one or more Borrowers under the Loan  Documents,  as amended hereby or as may be
hereafter amended, modified, supplemented or replaced.
         2.       Amendments to Loan and Security Agreement.
     2.1 The introductory paragraph of Section 1 to the Loan Agreement is hereby
deleted in its entirety and replaced with the following:
                  Subject to the terms and  conditions  of, and in reliance upon
                  the representations and warranties made in, this Agreement and
                  the other Loan Documents, Lender agrees to make a Total Credit
                  Facility  of  up  to  $50,000,000  available  upon  Borrowers'
                  request therefor, as follows:

     2.2 Section 1.1.1 of the Loan  Agreement is hereby  deleted in its entirety
and replaced with the following:
                                    1.1.1  Loans.  As a Part of the Total Credit
                  Facility,  Lender hereby establishes a subfacility pursuant to
                  which  Lender  agrees,  for so long as no  Default or Event of
                  Default  exists  and  subject to the  corresponding  Borrowing
                  Bases,  to make  Revolving  Credit Loans to, and for the joint
                  and  several  benefit  of,  Borrowers  from  time to time,  as
                  requested by  Borrowers in the manner set forth in  subsection
                  3.1.1 hereof.  Revolving Credit Loans may be made by Lender to
                  the  Telecommunication  Group up to a maximum principal amount
                  equal  to  the  Telecommunication  Group  Borrowing  Base  and
                  Revolving Credit Loans may be made to Southeastern Printing up
                  to a  maximum  principal  amount  equal  to  the  Southeastern
                  Printing Borrowing Base. In no event and at no time,  however,
                  shall the aggregate amount outstanding of all Revolving Credit
                  Loans  exceed  the lesser of (a) the  aggregate  amount of the
                  Borrowing  Bases or (b) an  amount  equal  to (i)  $50,000,000
                  minus (ii) the  aggregate  amount of all reserves (as provided
                  in Section 1.1.2. below), plus the outstanding LC Amount, plus
                  the aggregate amount  outstanding  under the Consolidated Term
                  Loan. If (x) the unpaid balance of Revolving Credit Loans made
                  to the  Telecommunication  Group exceeds the Telecommunication
                  Borrowing Base, or (y) the unpaid balance of Revolving  Credit
                  Loans made to Southeastern  Printing  exceed the  Southeastern
                  Printing  Borrowing  Base,  or (z) the  unpaid  balance of the
                  Revolving Credit Loans exceed any other  limitations set forth
                  in this  Agreement,  then such excess  Revolving  Credit Loans
                  shall  nevertheless  constitute  Obligations  that are due and
                  payable on demand,  secured by the  Collateral and entitled to
                  all  the  benefits  thereof.  Each  Borrower  is  jointly  and
                  severally  liable for all  Obligations.  All Revolving  Credit
                  Loans shall be repayable in  accordance  with the terms hereof
                  and the Revolving Credit Note.

     2.3 (a) As of  December  27,  1996,  the  aggregate  outstanding  principal
balance of all Equipment  Loans is equal to  $9,375,000.00  and the  outstanding
principal  balance  of the  Term  Loan is equal to  $9,031,618.84.  Pursuant  to
Borrowers'   request,   the  Equipment  Loans  and  the  Term  Loan  are  hereby
consolidated and reset as the "Consolidated Term Loan". In conjunction with this
Second Amendment, Lender shall advance an additional $3,593,381.16 such that the
initial  principal  balance  of the  Consolidated  Term  Loan  shall be equal to
$22,000,000.  The Consolidated Term Loan shall be repayable quarterly,  in equal
quarterly  installments of principal of $1,000,000 each on the first day of each
January,  April,  July and October with the entire  amount of such  Consolidated
Term Loan due and  payable  upon the earlier to occur of (a) the last day of the
Original Term, or if applicable, any Renewal Term, or (b) the termination of the
credit  Facility as provided  for in the Loan  Agreement,  or (c) the  scheduled
final repayment date based on the stated  repayment  schedule.  The Consolidated
Term Loan shall be evidenced by that certain Amended,  Restated and Consolidated
Term Note, which is hereby incorporated by reference.
                  (b)  Section 1.2 and  Section  1.3 of the Loan  Agreement  are
hereby  deleted in their  entirety and shall be deemed to be replaced by Section
1.3(a) of this Second Amendment.
                  (c) All  references  to the "Term Loan" and/or the  "Equipment
Loans" or an "Equipment Loan" contained in the Loan Agreement shall be deemed to
refer to the Consolidated Term Loan.
                  2.4 The  calculation of all financial  covenants  contained in
the Loan  Agreement and the  calculation  of EBIDTA for purposes of  determining
the-Revolving  Credit LIBOR Rate and the Term LIBOR Rate,  shall be based solely
on the results of the Borrowers' financial  performance,  and shall specifically
exclude the financial performance of any and all foreign subsidiaries  including
Telecomunication, S.A. ("Sintel").
         3.       Amendments to Appendix A/General Definitions.
     3.1 The definition of "Aggregate  Adjusted  Availability" is hereby deleted
in its entirety and replaced with the following:
                           Aggregate Adjusted  Availability - an amount equal to
                  the lesser of (a) the aggregate amounts of the Borrowing Bases
                  or (b)  $50,000,000,  less the sum of (i) the aggregate amount
                  of Loans and the LC Amount as of the date of calculation  plus
                  (ii) all sums due and owing to trade  creditors  which  remain
                  outstanding beyond normal trade terms or special terms granted
                  by trade  creditors,  plus  (iii)  any  reserves  against  the
                  Borrowing Bases, plus (iv) if applicable, closing payments and
                  expenses.

     3.2 The definition of "Bank" is hereby deleted in its entirety and replaced
with the following: Bank - Fleet National Bank.
     3.3 The  definition  of "Total  Credit  Facility" is hereby  deleted in its
entirety and replaced with the following:
     3.4 The definition of "Telecommunication Group" is hereby amended by adding
Harrison-Wright Co., Inc., Utility Precast,  Inc. and Carolina Com-tec,  Inc. as
members of the Telecommunications Group. Total Credit Facility - $50,000,000
     3.5  Appendix  A/General  Definitions  is  hereby  amended  by  adding  the
following definitions:  (a) Amended,  Restated and Consolidated Term Note - that
certain  promissory  which evidences the  Consolidated  Term Loan, which amends,
restates and consolidates the Master Equipment Note and the Term Note.
     (b)  Consolidated  Term Loan - As defined  in Section  2.3(a) of the Second
Amendment to Loan and
                                    -----------------------
Security Agreement.
     (c) Sintel - As defined in Section 2.4 of the Second  Amendment to Loan and
Security  Agreement.  4.  Collateral.   As  security  for  the  payment  of  the
Obligations, and satisfaction by Borrowers (including without
limitation HWC, UPI and CCI) of all covenants and undertakings  contained in the
Loan Agreement and the Loan Documents,  HWC, UPI and CCI each hereby assigns and
grants to  Lender a  continuing  first  Lien on  (except  with  respect  to such
Property  expressly  covered  by the Liens set  forth on  Exhibit A hereto)  and
security  interest  in, upon and to all of the  following,  whether now owned or
hereafter acquired, created or arising and wherever located ("Collateral"):
                           (a)      Accounts;
                           (b)      Inventory;
                           (c)      Equipment;
                           (d)      General Intangibles;
                           (e)      Fixtures;
                           (f)      Deposit Accounts;
     (g) All monies and other  Property  of any kind now or at any time or times
hereafter  in the  possession  or under  the  control  of  Lender or a bailee or
Affiliate of Lender; (h) All books and records  (including,  without limitation,
customer lists, credit files, computer programs,  print-outs, and other computer
materials  and records) of HWC, UPI and/or CCI  pertaining to any of (a) through
(g) above; and (i) All accessions to,  substitutions  for and all  replacements,
products and cash and non-cash
proceeds of all of the foregoing above, including, without limitation,  proceeds
of and unearned premiums with respect to insurance  policies insuring any of the
Collateral.
     5. Effectiveness Conditions.  This Second Amendment shall be effective upon
completion of the following  conditions  precedent  (all documents to be in form
and substance  satisfactory  to Lender and Lender's  counsel):  (a) Execution of
this Second Amendment to Loan and Security Agreement.
                  (b) Execution and delivery of the Second  Amended and Restated
Revolving  Credit Note which shall amend and  restate,  but not  extinguish  the
indebtedness  evidenced by, that certain Amended and Restated  Revolving  Credit
Note dated February 29, 1996.
                  (c) The Amended,  Restated and  Consolidated  Term Note, which
amends,  restates and consolidates  that Master Equipment Note, as amended,  and
that certain Term Note, as amended, each dated as of January 26, 1995.
                  (d) UCC-1 Financing  Statements to be executed by HWC, UPI and
CCI and filed in all jurisdictions which Lender may deem appropriate.
                  (e) Certified  copies of (i) the resolutions of each Borrower,
including without limitation HWC, UPI and CCI, authorizing the execution of this
Second Amendment,  the Notes to be issued hereunder,  and each document required
to be delivered by any section  hereof and (ii) HWC's,  UPI's and CCI's articles
of incorporation and by-laws.
                  (f)  Incumbency  Certificate  for  each  Borrower,   including
without  limitation HWC, UPI and CCI,  identifying all Authorized  Officers with
specimen signatures.
                  (g)  Evidence   satisfactory   to  Lender  in  its  reasonable
discretion  that the  acquisition of the Assets has been  completed  strictly in
accordance  with terms of the Purchase  Agreements and the delivery to Lender of
the fully executed Purchase Agreements and all related agreements.
                  (h) All Vehicle Titles (if  applicable)  owned by HWC, UPI and
CCI and pledged to Lender  pursuant to the terms hereof along with all completed
documentation necessary to have Lender's first lien noted thereon.
                  (i) Good Standing  Certificates of HWC, UPI and CCI from North
Carolina and their respective states of incorporation.
         6.  Confirmation  of  Indebtedness.  Borrowers  hereby  acknowledge and
confirm that as of the close of business on December  27,  1996,  they are each,
jointly and severally,  indebted to Lender,  without defense,  setoff,  claim or
counterclaim  under the Loan  Documents,  in the aggregate  principal  amount of
$36,296,849.08,  as well as reimbursement  for draws which may hereafter be made
on  Letters  of Credit  issued for the  benefit  of  Borrowers,  or any of them,
currently in the aggregate face amount of  $3,515,650.92,  plus all fees,  costs
and expenses (including attorney's fees) incurred to date in connection with the
Loan Documents.
         7.  Collateral.  Borrowers and Sureties  each hereby  confirm and agree
that all security  interests and Liens granted to Lender continue to be properly
perfected  and are in full  force and effect  and shall  continue  to secure the
Obligations.  All  Collateral  remains  free and clear of any Liens  other  than
Permitted  Liens  or  Liens in favor of  Lender.  Nothing  herein  contained  is
intended  to in any way  impair or limit the  validity,  priority  and extent of
Lender's existing security interest in and Liens upon the Collateral.
         8.       Reaffirmation of Sureties.
                  Each Surety, party to that certain Surety Agreement each dated
January  26, 1995 in favor of Lender,  by  execution  hereof in its  capacity as
surety,  hereby consents to the provisions of this Second  Amendment,  including
the  increase in the Total  Credit  Facility  and  acknowledges  that the Surety
Agreement remains in full force and effect and that it remains liable for all of
Borrowers' Obligations to Lender under the Loan Documents, as amended hereby.
         9.       Representations and Warranties.
                  9.1 Borrowers,  including without limitation HWC, UPI and CCI,
represent  and  warrant  that as of the  date  hereof  no Event  of  Default  or
Unmatured Event of Default has occurred or is existing under the Loan Documents.
                  9.2 The  execution  and delivery by each  Borrower,  including
without  limitation  HWC,  UPI and  CCI,  and by  each  Surety,  of this  Second
Amendment and performance by it of the transactions  herein contemplated (i) are
and will be  within  its  powers,  (ii) have been  authorized  by all  necessary
corporate  action,  and  (iii) are not and will not be in  contravention  of any
order of any court or other agency of government, of law or any other indenture,
agreement or undertaking to which such Borrower or Surety is a party or by which
the property of such Borrower or Surety is bound, or be in conflict with, result
in a breach of or  constitute  (with due notice  and/or lapse of time) a default
under any such  indenture,  agreement or undertaking or result in the imposition
of any lien,  charge or  encumbrance  of any nature on any of the  properties of
such Borrower or Surety.
                  9.3 This Second  Amendment,  the Notes referenced in Section 3
hereof,  and each  other  agreement,  instrument  or  document  executed  and/or
delivered in connection  herewith,  shall be valid,  binding and  enforceable in
accordance with its respective terms.
                  9.4 Each of the Borrowers,  including without limitation, HWC,
UPI and CCI, is organized  under the laws of the United States of America and is
in good  standing in all states where the failure to be in good  standing  might
have a material  adverse  effect on its  business or  operations  (financial  or
otherwise).
                  9.5 Borrowers,  including without limitation, HWC, UPI and CCI
and  Sureties  have no  liability  whatsoever  with  respect  to the  debts  and
liabilities of Sintel.
         10.      Governing Law.
                  This Second  Amendment  shall be governed  by,  construed  and
enforced in accordance with the laws of the Commonwealth of Pennsylvania.
         11.      Ratification of Loan Documents.
                  Except as expressly  provided herein, all terms and conditions
of the Loan  Documents  remain in full force and  effect,  unless  such terms or
conditions are no longer applicable by their terms. To the extent the provisions
of this Second Amendment are expressly  inconsistent  with the provisions of the
Loan Documents, the provisions of this Second Amendment shall control.
         12.      Counterparts
         This Second  Amendment  may be executed in any number of  counterparts,
each of which  when so  executed  shall be  deemed to be an  original,  and such
counterparts together shall constitute one and the same respective agreement.
         13.      Incorporation.
         This Second  Amendment  shall amend and is  incorporated  into the Loan
Agreement.
         IN  WITNESS  WHEREOF,  the  parties  hereto  have  caused  this  Second
Amendment  to be  executed  and  delivered  as of the day and year  first  above
written.

                         BORROWERS:

                         MASTEC, INC.
                         BURNUP & SIMS OF CALIFORNIA, INC.
                         BURNUP & SIMS OF THE CAROLINAS, INC.
                         BURNUP & SIMS COMMUNICATIONS SERVICES, INC.
                         BURNUP & SIMS COMTEC, INC.
                         BURNUP & SIMS NETWORK DESIGNS, INC.
                         BURNUP & SIMS TSI, INC.
                         BURNUP & SIMS TELECOM OF FLORIDA,INC.
                         BURNUP & SIMS OF TEXAS, INC.
                         CHURCH &  TOWER, INC.
                         CHURCH & TOWER FIBER TEL, INC.
                         CHURCH & TOWER OF FLORIDA, INC.
                         CHURCH & TOWER OF TN, INC.
                         DESIGNED TRAFFIC INSTALLATION, INC.
                         SOUTHEASTERN PRINTING COMPANY, INC.
                         UTILITY LINE MAINTENANCE, INC.


WITNESS/ATTEST:                     By:
                                                              Edwin D. Johnson
                           Title: On Behalf of, and as
                                  of each of the Foregoing
                                  Borrowers


                            HARRISON-WRIGHT CO., INC.


WITNESS/ATTEST:                     By:                       Edwin D. Johnson

                                                     Title:


                              UTILITY PRECAST, INC.


WITNESS/ATTEST:                     By:                       Edwin D. Johnson

                                                     Title:



                             CAROLINA COM-TEC, INC.


WITNESS/ATTEST:                     By:                       Edwin D. Johnson

                                                     Title:

                                         [SIGNATURES CONTINUED ON NEXT PAGE]

                    [SIGNATURES CONTINUED FROM PREVIOUS PAGE]

                                                     SURETIES:

                          MASTEC INTERNATIONAL, INC.
                          MASTEC WIRELESS, INC.
                          BURNUP & SIMS ENTERPRISES, INC.
                          BURNUP: SIMS OF MISSISSIPPI, INC.
                          BURNUP & SIMS COMMUNICATIONS SERVICES OF FLORIDA, INC.
                          CAL TECHNICAL SERVICES, INC.
                          CAPSCAN CABLE COMPANY, INC.
                          GDSI, INC.
                          CONSTRUCTION EQUIPMENT SYSTEMS CORPORATION
                          LATLINK CORP., f/k/a MASTEC EQUIPMENT
                          COMPANY, INC.
                          TELINK, INC.


WITNESS/ATTEST:                     By:
                                                              Edwin D. Johnson
                           Title: On Behalf of, and as
                                  of each of the Foregoing
                                  Borrowers



                   LENDER:

     FLEET CAPITAL CORPORATION, f/k/a SHAWMUT CAPITAL CORPORATION,  SUCCESSOR TO
BARCLAYS BUSINESS CREDIT, INC.

                                                     By:       Howard Handman

                                                     Title: