1


DATED                                                              1994
_______________________________________________________________________







                        BAKER HUGHES LIMITED       (1)


                      NAVSTAR SYSTEMS.LIMITED      (2)

                         SYMMETRICOM INC           (3)








_______________________________________________________________________

                               UNDERLEASE

                                   of

                       Premises at Mansard Close
                      Westgate Interchange Estate
                              Northampton
_______________________________________________________________________








                             Osborne Clarke
                        30 Queen Charlotte Street
                            Bristol BS99 7QQ

                               78/3580l4



                          PARTICULARS

1.    DATE OF THIS DEED               day Of                  1994

2.    LEASE OR UNDERLEASE           UNDERLEASE

3.    LANDLORD                      BAKER HUGHES LIMITED (Company 
                                    Number 1388658) whose registered 
                                    office is at Hammersley House 5-8 
                                    Warwick Street London WlR 5RA

4.     TENANT                       NAVSTAR SYSTEMS LIMITED (Company 
                                    Number 2801218 ) whose registered 
                                    office is at 3 The Billings 
                                    Walnut Tree Close Guildford Surrey

5.     SURETY                       SYMMETRICOM INC whose registered 
                                    office is at 85 West Tasman Drive 
                                    San Jose, California 95134-1703

6.     SITE                         premises at Mansard Close Westgate 
                                    Interchange Estate Northampton as 
                                    shown edged blue on the annexed plan

7.     DEMISED PREMISES             premises at the site as shown edged 
                                    red on the annexed plan

8.     DATE OF COMMENCEMENT
       OF TERM                      5th day of April 1994

9.     LENGTH OF TERM               10 years

10.    EXPIRY DATE OF TERM          4th day of April 2004

11.    RENT(S) as they may be
       reviewed under the Third
       Schedule                     72,000  pounds per annum

12.    RENT COMMENCEMENT DATE       5th day of October 1994

13.    RENT REVIEW DATE             29th September 1995 and 29th 
                                    September 2000 

14.    USER                         Any use falling within Class III 
                                    and/or Class X of the Town and 
                                    Country Planning (Use Classes) Order 
                                    1972

15.    HEAD LEASE                   means a Lease of the Site dated the 
                                    19th December 1985 made between 
                                    Strathclyde Regional Council (1) and 
                                    the Landlord (then called Baker 
                                    International Limited) and 
                                    references herein to superior leases 
                                    shall include the Head Lease

16.    HEAD LANDLORD                means any person  from time to time 
                                    entitled (whether immediately or 
                                    not) to the reversion expectant on 
                                    the determination of the term 
                                    granted by the Head Lease and 
                                    references herein to superior 
                                    landlord shall include the Head 
                                    Landlord

17.    SCHEDULE OF CONDITION        means a schedule of the condition of 
                                    the Demised Premises and the Common 
                                    Parts agreed between the Landlord 
                                    and the Tenant's respective 
                                    surveyors and annexed hereto 


THIS LEASE made on the date stated in the Particulars B E T W E E N

(1)   the Landlord specified in the Particulars ("the Landlord")
(2)   the Tenant specified in the Particulars ("the Tenant") 
WITNESSES:-
1.    Definitions
      ___________
IN this Lease the following expressions (where the context so admits) 
shall have the following meanings:-

"the Particulars"                   The details on the preceding pages 
                                    headed "Particulars"

"the Plan"                          The plan or plans specified in the 
                                    Particulars

"the Term"                          The term mentioned in the 
                                    Particulars

"the Termination Date"              The date of expiration or sooner 
                                    determination of the Term 

"the Demised Premises"              The whole and every part of the land 
                                    described in the Particulars
                                    together with everything for the 
                                    time being on the land and/or 
                                    appurtenant to it (excluding any 
                                    tenants fixtures and fittings and 
                                    any matters the property of 
                                    statutory undertakings) provided 
                                    that the wall separating the 
                                    said premises from the adjoining 
                                    building on the Site shall be 
                                    included only to the extent of the 
                                    median line thereof

"Conduit"                           Any sewers drains pipe wires ducts 
                                    cables and other conducting media or 
                                    other thing within the Demised 
                                    Premises by means of which gas 
                                    electricity water soil or any other 
                                    facility service or matter may pass

"Requisite Notice"                  A notice  in writing to the Tenant 
                                    forty eight hours before any entry 
                                    is made on the Demised Premises or 
                                    such notice to the Landlord before 
                                    any entry is made on the Site (as 
                                    the case may be) PROVIDED THAT in 
                                    the case of an emergency no notice 
                                    shall be required

"the Insured Risks"                 The risks insured against under 
                                    Clause 4.1

"Landlord"                          shall include the person entitled 
                                    for the time being to the reversion 
                                    of this Lease

"Tenant"                            shall (unless the context otherwise 
                                    admits) include the Tenant's 
                                    successors in title and if it is an 
                                    individual his personal 
                                    representatives

"Surety"                            shall include if it is an individual 
                                    his personal representatives

"Interest"                          Interest at the rate of 3% above 
                                    Bank of Scotland Base Rate for the 
                                    time being payable on any monies due 
                                    and payable by the Tenant to the 
                                    Landlord (if due payment is not made 
                                    by the Tenant within 14 days of 
                                    demand) from the date of demand by 
                                    the Landlord until the date of 
                                    payment to the Landlord

"Act"                               Shall mean every Act of Parliament 
                                    (whether specifically named herein 
                                    or not) which may be relevant to the 
                                    Demised Premises its user or 
                                    anything on the Demised Premises the 
                                    persons employed thereon or having 
                                    recourse thereto whether or not in 
                                    force at the date hereof and shall 
                                    include any statutory re-enactment 
                                    or modification thereof and any 
                                    order regulation directive bye law 
                                    rule consent or licence granted or 
                                    required thereunder or by any Public 
                                    or local authority or by any court 
                                    of competent jurisdiction

"Common Parts"                      shall mean all ways passages roads 
                                    pavements sewers drains sanitary 
                                    apparatus pipes gutters watercourses 
                                    walls structures fences and other 
                                    conveniences which shall belong to 
                                    or be used by or in connection with 
                                    the Demised Premises in common with 
                                    the remainder of the Site and other 
                                    premises near or adjoining thereto

2.   IN THIS LEASE
     _____________
     2.1.   The details and descriptions appearing in the Particulars 
            shall be included and form part of the Lease
     2.2.   If there shall be more than one person included in the 
            expression "Tenant" or "Surety" the covenants by them shall 
            be joint and several 
     2.3.   Where any act is prohibited the Tenant shall not allow or 
            suffer such act to be done 
     2.4.   Where the Landlord or any other person exercises any rights 
            to enter the Demised Premises under this Lease unless 
            specifically provided herein to the contrary the person 
            exercising such right will forthwith make good any damage 
            caused to the Demised Premises but neither such person nor 
            the Landlord shall be liable for any other compensation

3.  DEMISE
    ______
THE Landlord DEMISES to the Tenant ALL THOSE the Demised Premises 
TOGETHER with so far as the Landlord has title to grant the same the 
easements and rights specified in the First Schedule EXCEPTING AND 
RESERVING to the Landlord the rights and easements specified in the 
Second Schedule TO HOLD the Demised Premises to the Tenant from and 
including the Date of Commencement of Term for the Term SUBJECT to all 
rights easements privileges restrictions and stipulations of whatever 
nature and other matters referred to in the documents (if any) specified 
in the Fifth Schedule YIELDING AND PAYING
     3.1.   yearly  and proportionately for any fraction of a year from 
            and including the Rent Commencement Date the rents specified 
            in Clause 11 of the Particulars and from and including each 
            of the rent review dates referred to in the Particulars such 
            other rent as may become payable under the provisions of the 
            Third Schedule to be paid (by bankers order if the Landlord 
            so requires) by equal quarterly payments in advance on the 
            usual quarter days in every year the first such payment to 
            be made today and to be in respect of the period from and 
            including the Rent Commencement Date to the quarter day 
            following whichever is the later of today's date and the 
            Rent Commencement Date save that for the purposes of this 
            Clause 3.1 for the period from the first rent review date 
            until the fifth anniversary of the date hereof the Tenant 
            shall pay the rent specified in the Particulars instead of 
            the reviewed rent
     3.2.   the insurance rent as determined pursuant to Clause 4 hereof 
            and Interest and all other sums whatsoever as shall become 
            payable by the Tenant to the Landlord under the provisions 
            of  this Lease which are all hereby reserved as rent 
     3.3.   on demand as further or additional rent a due proportion (to 
            be reasonably determined by the Landlord) of the reasonable 
            costs and expenses properly incurred (including those 
            required under or by virtue of any Act of Parliament or 
            local Bye-Law or any enactment or statutory instrument for 
            the time being in force or by any competent public or local 
            authority or otherwise) of repairing maintaining rebuilding 
            lighting and cleansing all Common Parts and to keep the 
            Landlord indemnified against all such reasonable costs and 
            expenses as aforesaid and all reasonable costs and fees of 
            professional advisers reasonably and properly incurred in 
            connection therewith PROVIDED THAT the Tenant shall not be 
            obliged or be liable to pay a due proportion of the costs 
            and expenses of:-
            3 3.1.    putting and keeping the Common Parts in any 
                      better condition than that shown in the Schedule 
                      of Condition 
            3.3.2.    or remedying any damage to the Common Parts due 
                      to any defect or deterioration in the Common Parts 
                      which is the direct or indirect result of any 
                      fault in the initial design  the siting or the 
                      method of construction of the Common Parts  or 
                      any part or parts thereof

4.   INSURANCE
     _________
     4.1.   Subject to the Tenant paying the premium in accordance with 
            the provisions of this clause the Landlord hereby covenants 
            with the Tenant that the Landlord will procure the insurance 
            of the Demised Premises and the remaining part or parts of 
            the Site subject to such excesses exclusions or limitations 
            as the Head Landlord or its Insurers require in such 
            reputable insurance office or with such underwriters and 
            through such agency as the Head Landlord may from time to 
            time decide in the full reinstatement value of the Demised 
            Premises or such higher value as the Tenant may reasonably 
            require including Architects and Surveyors and other 
            professional fees and incidental expenses against:-
            4.1.1.    Loss or damage by fire explosion storm tempest 
                      (including lightning) flood burst pipes impact 
                      and (in peacetime) aircraft and articles dropped 
                      therefrom riot civil commotion and malicious 
                      damage and such other risks which the Landlord 
                      may from time to time deem necessary or such 
                      other risks against which insurance has been 
                      effected 
            4.1.2.    Public Liability of the Landlord and the Head 
                      Landlord arising out of or in connection with any 
                      matter involving or relating to the Demised 
                      Premises and the remaining part or parts of the 
                      Site
            4.1.3.    The loss of rent payable under this Lease from 
                      time to time (having regard to any review of rent 
                      which may become due under this Lease) for three 
                      years or such longer period as the Head Landlord 
                      may from time to time reasonably consider to be 
                      sufficient for the purposes of planning and 
                      carrying out any such reinstatement
     4.2.   The Tenant shall pay to the Landlord on demand the amount of 
            the premium for insuring the Demised Premises against the
            Insured Risks from the Date of Commencement of Term as 
            reasonably determined by the Landlord
     4.3.   At the reasonable request of the Tenant the Landlord will 
            produce evidence of such insurance and of the payment of the 
            last premium
     4.4.   If any part of the Demised Premises or any part of the Site 
            over which rights are granted to the Tenant is damaged by 
            any of the Insured Risks and becomes unfit for occupation 
            and use and the policy or policies of insurance shall not 
            have been vitiated or payment refused in whole or part as a 
            result of some act or default of the Tenant then the rents 
            or a fair proportion of the rents according to the nature 
            and extent of the damage shall be suspended until the 
            Demised Premises or such parts of the Common Parts shall be 
            fit for occupation and use or accessible and the Landlord 
            shall forthwith repay to the Tenant any rent paid in advance 
            in respect of a period after the date of such destruction or 
            damage and any dispute regarding the cesser of rent shall be 
            referred to a single arbitrator to be appointed in default 
            of agreement upon the application of either party by the 
            President for the time being of the Royal Institution of 
            Chartered Surveyors under the Arbitration 
            Acts 1950 to 1979
            4.4.1.    If the Demised Premises or any part of the Site 
                      over which rights are granted to the Tenant are 
                      damaged by any of the Insured Risks then unless 
                      payment of the insurance monies shall be refused 
                      in whole or part by reason of any act or default 
                      of the Tenant or anyone under its control and the 
                      Tenant does not comply with Clause 4.4.2. hereof 
                      and subject to the Head Landlord being able to 
                      obtain all necessary consents the Landlord hereby 
                      covenants with the Tenant that the Landlord will 
                      use all reasonable endeavours to ensure that the 
                      Head Landlord lays out the proceeds of such 
                      insurance in reinstating the Demised Premises and 
                      any part of the Site over which rights are granted 
                      to the Tenant and the Tenant will pay to the 
                      Landlord on demand with Interest (if appropriate) 
                      the amount equivalent to any excess which may be 
                      applicable to such insurance
            4.4.2.    If the payment of any insurance monies is refused 
                      in whole or in part as provided in Clause 4.4.1 by 
                      any act or default of the Tenant or anyone under 
                      its control then the Tenant will pay to the 
                      Landlord on demand and with Interest (if 
                      appropriate) the amount so refused
     4.5.   The Tenant will not do anything which may prejudice any 
            policy of insurance for the time being in force in respect 
            of any part of the Demised Premises or any part of the Site 
            over which rights are granted to the Tenant or which may 
            result in such insurance becoming void or voidable or the 
            rate of premium under such insurances being increased 
            (unless previously authorised by the Landlord the Head 
            Landlord and the insurers and the Tenant shall elect to 
            pay the increased premium) and the Tenant will at all 
            times comply with all requirements of the insurers of the 
            Demised Premises
     4.6.   The Tenant will keep the Demised Premises supplied with such 
            fire fighting equipment as the insurers of the Demised 
            Premises and the competent Fire Authority may require or 
            as the Landlord may reasonably require and maintain such 
            equipment to the satisfaction of all such persons
     4.7.   The Tenant will not store especially inflammable or 
            explosive substances or goods at the Demised Premises or 
            obstruct the access to any fire fighting equipment or the 
            means of escape from or over the Demised Premises and in the 
            event of anything happening which might affect any insurance 
            policy relating to the Demised Premises forthwith to give 
            notice to the Landlord
     4.8.   The Tenant will insure in the joint names of the Landlord 
            the Head Landlord and the Tenant all plate glass (if any) in 
            the Demised Premises against breakage or damage in its full 
            reinstatement value for the time being with an insurance 
            office or underwriters approved in writing by the Landlord 
            (such approval not to be unreasonably refused or delayed) 
            and will produce to the Landlord on demand (but not more 
            than once in any period of twelve months) evidence of such 
            insurance and the payment of the current years premium and 
            all monies received from such insurance shall be laid
            out as soon as possible in reinstating the plate glass and 
            any deficiency will be made up from the Tenants own monies 
            and subject hereto the Tenant will not effect any insurance 
            over the Demised Premises in respect of any of the Insured 
            Risks
     4.9.   The Tenant will on demand repay to the Landlord the 
            reasonable and proper costs incurred in obtaining valuations 
            of the Demised Premises for insurance purposes from time to 
            time but no more frequently than once every three years

5.   TENANT'S OBLIGATIONS
     ____________________
THE Tenant COVENANTS with the Landlord:
     5.1.   Rents
            To pay the rents reserved by this Lease without deduction in 
            accordance with its terms and in the event that any rent 
            shall be unpaid for more than fourteen days after the due 
            date (and in the case only of the rent reserved by Clause 
            3.1 hereof whether formally demanded or not) to pay 
            Interest
     5.2.   5.2.1.    Repair and Decoration
                      _____________________
                      Subject to the provisions of Clause 5.2.6 at all 
                      times to repair and to keep the Demised Premises 
                      in good and substantial repair and condition free 
                      from all defects and to yield up the same at the 
                      Termination Date in accordance with the covenants 
                      by the Tenant contained in this Lease (damage by 
                      any of the Insured Risks excepted unless payment 
                      of the insurance moneys shall be withheld in whole 
                      or in part by reason solely or in part of any act 
                      or default of the Tenant its servants or agents) 
                      PROVIDED THAT the Tenant shall not be obliged to 
                      put or keep the Demised Premises in any better 
                      condition than as set out in the Schedule of 
                      Condition
            5.2.2.    To keep the Demised Premises (including any part 
                      unbuilt on) and all conduits in a clean and tidy 
                      condition and properly cleansed and free from 
                      obstruction and in particular to clean all the 
                      windows (both inside and out) and all other glass 
                      in the Demised Premises monthly
            5.2.3.    Decoration
                      __________
                      Without prejudice to the generality of the 
                      foregoing
                      5.2.3.1.    during the first year and every 
                                  succeeding third year and in the last 
                                  six months of the Term (PROVIDED THAT 
                                  the Tenant shall not be liable so to 
                                  do more frequently than once every 24 
                                  months) to paint and otherwise treat 
                                  as the case may be all the outside of 
                                  the Demised Premises usually so 
                                  treated in a workmanlike manner to the 
                                  reasonable satisfaction of the Head 
                                  Landlord in colours to be approved by 
                                  the Head Landlord AND as often as in 
                                  the reasonable opinion of the Landlord 
                                  may be necessary and in any event 
                                  during the last three months of the 
                                  Term to clean all external surfaces of
                                  the Demised Premises and to repoint 
                                  any brickwork
                      5.2.3.2.    during the second year and every 
                                  succeeding fifth year and in the last 
                                  six months of the Term (Provided That 
                                  the Tenant shall not be liable so to 
                                  do more frequently than once every 
                                  twenty four months) to paint and 
                                  otherwise treat as the case may be all 
                                  the inside wood and metal work of the 
                                  Demised Premises usually painted or 
                                  otherwise treated in a workmanlike 
                                  manner to the reasonable satisfaction 
                                  of the Landlord and also clean all 
                                  other inside parts of the Demised 
                                  Premises and to paint or paper in a 
                                  workmanlike manner all walls and 
                                  ceilings of the Demised Premises 
                                  usually painted or papered as the 
                                  case may be such decorations in the 
                                  last three months of the Term to be 
                                  executed in such colours patterns and 
                                  materials as the Head Landlord may 
                                  require
                      5.2.3.3.    Where painting is required under any 
                                  of the preceding paragraphs in the 
                                  case of exterior painting it shall 
                                  consist of a priming coat and three 
                                  coats of good quality paint and in 
                                  the case of interior painting three 
                                  coats of good quality paint and in 
                                  every case materials of good quality 
                                  only shall be used
            5.2.4.    To repair or replace forthwith by new articles of 
                      similar kind and quality any fixtures fittings or 
                      plant or equipment (other than tenants or trade 
                      fixtures and fittings) in the Demised Premises 
                      which shall become in need of repair or 
                      replacement
            5.2.5.    To keep any part of the Demised Premises which 
                      may not be built upon adequately surfaced in 
                      good condition properly mowed (if grass) and 
                      free from weeds and all lanascaped areas 
                      properly cultivated 
            5.2.6.    The Tenant's liability to keep the Demised 
                      Premises in good and substantial repair and 
                      condition shall not apply to damage due to any 
                      defects or deterioration in the Demised Premises 
                      which is the direct or indirect result of any 
                      fault in the initial design the siting or the 
                      method of construction of the Demised Premises 
                      and/or the building or any part or parts thereof
     5.3.   Alterations and additions
            _________________________
            5.3.1. That no new building or new structure of any kind 
                   shall at any time be erected upon any part of the 
                   Demised Premises  
            5.3.2. Not to make any internal or external alterations 
                   or additions to any part of the Demised Premises and 
                   not to cut maim or remove structural parts of the 
                   Demised Premises and not to make any change in the 
                   existing design or appearance of the Demised Premises 
                   PROVIDED ALWAYS that the Tenant may with the prior 
                   written consent of the Landlord (such consent not to 
                   be unreasonably withheld or delayed) carry out 
                   internal non-structural alterations to any buildings 
                   for the time being erected on the Demised Premises
     5.4.   User
            _____
            At all times during the said term to use the Demised 
            Premises for the User specified in the Particulars and 
            not to use the same or any part for any other purpose
     5.5.   Alienation
            __________
            5.5.1. Not to assign charge or underlet or part with or 
                   share the possession or occupation of any part or 
                   parts (as distinct from the whole) of the Demised 
                   Premises and not to agree so to do
            5.5.2. Not to underlet part with or share possession of the 
                   whole of the Demised Premises or agree so to do or 
                   permit anyperson to occupy the same save by way 
                   of an assignment of the whole of the Demised 
                   Premises in accordance with theprovisions 
                   hereinafter contained
            5.5.3. Without prejudice to the foregoing provisions of 
                   this sub-clause not to assign or charge the whole 
                   of the Demised Premises without the previous written 
                   consent of the Landlord such consent not to be 
                   unreasonably withheld or delayed
            5.5.4. On any assignment to procure that the Assignee 
                   enters into a covenant with the Landlord to pay 
                   the rents reserved byand perform and observe the 
                   covenants on the part of the Tenant contained in 
                   this Deed
            5.5.5. If the Landlord  shall  reasonably so require to 
                   obtain acceptable Guarantors for any person to 
                   whom this Lease is to be assigned who shall covenant 
                   with the Landlord in the terms (mutatis mutandis) 
                   set out in the Fourth Schedule hereto
            5.5.6. Not to vary the terms of or accept any surrender of
                   any underlease permitted under this clause (or agree 
                   so to do) without the Head Landlord's and the 
                   Landlord's written consent (such consent not to be 
                   unreasonably withheld or delayed)
            5.5.7. Within one month after the transmission of any 
                   interest under this Lease or derivative on it or 
                   the execution of any document dealing with such 
                   interest to produce to and leave with the Landlord 
                   the Deed instrument or other document evidencing or 
                   effecting such dealing or transmission together with 
                   the Landlord's registration fee of 20 and with such 
                   reasonable registration fee as the Head Landlord may 
                   require PROVIDED THAT registration of any such deed 
                   instrument or other document shall be evidence of 
                   notification of such transaction to the Landlord but 
                   shall not require the Landlord to consider the terms 
                   of such transaction or of the said deed instrument or 
                   other document and shall not be evidence that it has 
                   done so
     5.6.  Entry
           _____
           5.6.1.     To permit the Landlord and all persons authorised 
                      by it at all reasonable times upon Requisite 
                      Notice to enter upon the Demised Premises:
                      5.6.1.1.    to examine their condition and to take 
                                  schedules of repairs and the like and 
                                  inventories of and fittings plant and 
                                  machinery 
                      5.6.1.2.    to execute any works of construction 
                                  repair decoration or of any other 
                                  nature on any adjoining or 
                                  neighbouring premises and to carry 
                                  out any repairs decorations or other 
                                  work which the Landlord must or may 
                                  carry out under the provisions of this 
                                  Lease upon or to the Demised Premises 
                     5.6.1.3.     for any other reasonable and proper 
                                  purpose connected with the interest of 
                                  the Landlord in the Demised Premises 
                                  including (without prejudice to the 
                                  generality of the foregoing) for the 
                                  purpose of valuing or disposing of any 
                                  interest of the Landlord or any 
                                  superior landlord or doing anything 
                                  which may be reasonably necessary to 
                                  prevent a forfeiture of any superior 
                                  lease for the time being affecting the 
                                  Demised Premises 
                     5.6.1.4.     in the last six months of the Term to 
                                  affix a sign or signs indicating that 
                                  the Demised Premises are to let unless 
                                  the Tenant enjoys a statutory right to 
                                  renew this Lease 
                    5.6.1.5.      The person or persons exercising the 
                                  right of entry  contained in this 
                                  Clause 5.6.1. shall cause as little 
                                  interference with the Tenant's use 
                                  and/or enjoyment of the Demised 
                                  Premises and/or the Tenant's business 
                                  as reasonably possible and forthwith 
                                  make good all damage thereby caused to 
                                  the reasonable satisfaction of the 
                                  Tenant and the right of entry is 
                                  subject thereto
           5.6.2.   If as a result of an inspection or otherwise the 
                    Landlord becomes aware of any breaches of covenant 
                    by the Tenant hereunder the Landlord may give notice 
                    in writing thereof to the Tenant and within two 
                    months after every such notice or sooner if 
                    reasonably required the Tenant shall remedy such 
                    breach of covenant in accordance with such notice 
                    and the covenants contained in this Lease to the 
                    reasonable satisfaction of the Landlord AND if the 
                    Tenant shall fail within two months of such notice 
                    or immediately in case of emergency to commence and 
                    to diligently and expeditiously continue to comply 
                    with such notice or if the Tenant shall at any time 
                    make default in the performance of any of the 
                    covenants contained in this Lease for or relating 
                    to the repair decoration or maintenance of the 
                    Demised Premises then (without prejudice to the 
                    right or re-entry and forfeiture hereinafter 
                    contained) the Landlord may enter upon the Demised 
                    Premises pursuant to and subject to the provisions 
                    of Clause 5.6.1 hereof and carry out or cause to be 
                    carried out all or any of the works referred to in 
                    such notice or remedy the default of the Tenant and 
                    in such circumstances the Landlord shall be under 
                    no liability to make good any damage whatsoever 
                    and all reasonable costs of all such works and all 
                    expenses properly incurred in remedying such 
                    defaults in each case together with Interest (if 
                    applicable) shall be paid by the Tenant to the 
                    Landlord on demand 
     5.7.  Town and Country Planning Acts and Acts Generally
           _________________________________________________
           5.7.1.   To comply with al1 Acts (including without 
                    prejudice to the generality of the foregoing the 
                    Town and Country Planning Acts 1971 to 1991)
           5.7.2.   At its expense to obtain from the appropriate 
                    authorities all licences consents and permissions 
                    as may be required for the carrying out by the 
                    Tenant of any operations or use on any part of the 
                    Demised Premises 
           5.7.3.   Not to make any application for planning permission 
                    without first producing a copy of the same and 
                    obtaining the prior written consent of the Landlord 
                    to such application which consent shall not be 
                    unreasonably withheld or delayed 
           5.7.4.   Notwithstanding any consent which may be granted by 
                    the Landlord under this Lease not to carry out or 
                    make any alteration or addition to the Demised 
                    Premises or any change of use thereof (being an 
                    alteration addition or change of use for which a 
                    planning permission needs to be obtained) before a 
                    planning permission therefor has been produced to 
                    the Landlord and acknowledged by it in writing as 
                    being satisfactory to it such acknowledgement 
                    (subject to the proviso contained in this sub-
                    clause) not to be unreasonably withheld or delayed 
                    PROVIDED ALWAYS that the Landlord may refuse so to 
                    express its satisfaction with any such planning 
                    permission on the ground that the period thereof 
                    or anything contained therein or omitted therefrom 
                    in the reasonable opinion of the Head Landlord or 
                    its Surveyor would be or be likely to be prejudicial 
                    to the Head Landlords interest in the Demised 
                    Premises whether during the said term or following 
                    the expiration thereof or likely to involve the Head 
                    Landlord in liability to Development Land Tax or 
                    any similar or substituted tax or charge on 
                    development gains 
           5.7.5.   Unless the Landlord shall otherwise in writing 
                    direct to carry out before the Termination Date 
                    any works stipulated to be carried out to the 
                    Demised Premises as a condition of any planning 
                    permission which may have been granted during the 
                    Term and implemented by the Tenant or any other 
                    person whether or not the date by which the 
                    planning permission requires such works to be 
                    carried out falls within the Term
           5.7.6.   In any case where a Planning Permission granted 
                    is granted subject to conditions and if the Head 
                    Landlord reasonably so requires to provide 
                    reasonable security for the compliance with such 
                    conditions and such planning permission shall not 
                    be implemented until such security shall have been 
                    provided
           5.7.7.   If reasonably required by the Landlord but at 
                    the cost of the Tenant to appeal to the Secretary 
                    of State against any refusal of planning permission 
                    or the imposition of any conditions on a planning 
                    permission in either case made pursuant to an 
                    application therefor under this sub-clause PROVIDED 
                    THAT the Tenant shall not be obliged to appeal 
                    against the decision of the Secretary of State 
           5.7.8.   Within seven days of the receipt of notice thereof 
                    to give full particulars to the Landlord of any 
                    permission notice order or proposal relevant to 
                    the Demised Premises or to the use thereof given to 
                    the Tenant or the occupier of the Demised Premises 
                    (together with a copy of any notice permission 
                    letter or document) under the Planning Acts or any 
                    Act and without delay to take all necessary steps 
                    to comply therewith with the written approval of 
                    the Landlord (such approval not to be unreasonably 
                    withheld or delayed) and also at the request of the 
                    Landlord to make or join with the Landlord in making 
                    such objections and representations against or in 
                    respect of any such notice order or proposal as 
                    aforesaid as the Landlord shall reasonably require 
                    the cost of which is to be shared equally between 
                    the Landlord and the Tenant 
     5.8.  Outgoings Costs and Fees
           ________________________
           5.8.1.   To pay and discharge all existing and future rates 
                    taxes duties charges assessments impositions and 
                    outgoings whatsoever and whether or not of a non-
                    recurring nature (hereinafter called "outgoings") 
                    which now are or may be charged levied assessed or 
                    imposed upon the Demised Premises or upon the owner 
                    or occupier thereof and to pay bear and discharge 
                    the proportion properly attributable to the Demised 
                    Premises of any outgoings as may be charged levied 
                    assessed or imposed upon any premises of which the 
                    Demised Premises form part (such proportion to be 
                    reasonably determined by the Surveyor for the time 
                    being to the Landlord) and not to make any claim 
                    for relief against outgoings payable in respect of 
                    the Demised Premises without the Landlords prior 
                    written consent such consent not to be unreasonably 
                    withheld or delayed 
           5.8.2.   To pay to the Landlord all costs charges and 
                    expenses(including professional advisers costs and 
                    fees) incurred by any superior Landlord and/or 
                    reasonably and properly incurred by the Landlord
                    5.8.2.1.   In or in contemplation of any proceedings 
                               under Sections 146 or 147 of the Law of 
                               Property Act 1925 including the 
                               preparation and service of notice 
                               thereunder (notwithstanding forfeiture 
                               is avoided otherwise than by relief 
                               granted by the Court)
                    5.8.2.2.   In the preparation and service of a 
                               Schedule of Dilapidations at any time 
                               during the Term or within three months 
                               after the Term expires 
                    5.8.2.3.   In  respect of any application for 
                               consent required by this Lease whether 
                               or not such consent be granted 
           5.8.3.   If any payments of rent or otherwise are to be made 
                    by the Tenant under this Lease (hereafter in this 
                    clause called "the Payments") to the Landlord or 
                    any person on the Landlord's behalf the Tenant 
                    shall pay by way of further rent any Value Added 
                    Tax which is or may become payable in respect of 
                    the Payments together with Interest unless in the 
                    case of third party costs charges and expenses the 
                    same are recoverable by the Landlord as Input Tax 
                    and irrecoverable by the Tenant Provided Always 
                    that wherever appropriate the person to whom the 
                    Payments are made shall as a condition of payment 
                    supply the Tenant with  the appropriate V.A.T. 
                    invoice 
     5.9.  General Requirement concerning use
           __________________________________
           5.9.1.   Not to use any part of the Demised Premises for any 
                    noxious noisy or offensive trade or business or 
                    for any illegal or immoral act or purpose nor for 
                    any sale by auction and not to commit any nuisance 
                    or do anything which may be or become an 
                    inconvenience or cause damage or disturbance to the 
                    Landlord or any other person PROVIDED THAT this 
                    shall not restrict or prohibit the Tenant using 
                    the Demised Premises for the User authorised herein
           5.9.2.   Not to allow empty containers or rubbish of any
                    description to accumulate upon the Demised 
                    Premises nor to discharge into any Conduit any 
                    deleterious matter or any substance which might be 
                    or become a source of danger or injury to the 
                    drainage system of the Demised Premises or any 
                    other property or person 
           5.9.3.   Not to use any part of the Demised Premises in 
                    such manner as to subject it to any strain or 
                    interference which is not reasonable or is in 
                    excess of that which the Demised Premises were 
                    designed to bear and not to install machinery on 
                    the Demised Premises which shall be unduly noisy 
                    or cause vibration
           5.9.4.   Not to do anything on the Demised Premises which 
                    might reasonably be expected to produce directly or 
                    indirectly corrosive fumes or vapours or moisture 
                    or humidity in excess of that which the Demised 
                    Premises were designed to bear and are otherwise 
                    reasonable
           5.9.5.   Not to erect or display any mast or pole flag 
                    signboard advertisement inscription bill placard 
                    or sign whatsoever on the Demised Premises or the 
                    windows thereof so as to be seen from the exterior 
                    without the previous written consent of the Landlord 
                    which shall not be unreasonably withheld or delayed 
                    in respect of a sign stating the Tenant's name and 
                    business or profession (such sign if the Landlord so 
                    requires to be removed and any damage caused thereby 
                    made good by the Tenant at the Termination Date)
           5.9.6.   To comply with all reasonable regulations made by 
                    the Landlord (in the interest of good estate 
                    management) or the Head Landlord from time to time 
                    for the management of the Demised Premises and/or 
                    any land or premises used or to be used in common or 
                    jointly with any other person
           5.9.7.   Not to load or unload any vehicle unless the vehicle 
                    shall be in a loading area provided for that purpose 
                    and not to obstruct or damage any access ways roads 
                    or landscaped areas in or leading to the Demised 
                    Premises 
           5.9.8.   To give written notice to the Landlord of any defect 
                    in the Demised Premises which might give rise to an 
                    obligation on the Landlord to do or refrain from 
                    doing any act or thing in order to comply with the 
                    duty of care imposed on the Landlord pursuant to the 
                    Defective Premises Act 1972 and at all times to 
                    display and maintain all notices which the Tenant 
                    is from time to time required under the provisions 
                    of any Act to display at the Demised Premises or the 
                    Head Landlord reasonably requires to be so displayed 
           5.9.9.   Not to stop up or paint out any windows at the 
                    Demised Premises and not to permit any encroachment 
                    upon the Demised Premises or the acquisition of any 
                    new right to light passage drainage or other 
                    easement over any part of the Demised Premises and 
                    to give immediate written notice to the Landlord of 
                    any threat of such encroachment or acquisition and 
                    at the Landlord's written request to take such 
                    action as the Landlord may reasonably require to 
                    prevent such encroachment or acquisition 
     5.10.      New Guarantor
                _____________
           Within fourteen days of the death during the Term of any 
           person who has or shall have guaranteed to the Landlord the 
           Tenants obligations contained in this lease or of such person 
           becoming bankrupt or having a Receiving Order made against 
           him or being a Company passing a Resolution to wind up or 
           entering into liquidation (other than for the purpose of 
           reconstruction or amalgamation whilst solvent) then to give 
           notice thereof to the Landlord and if so required by the 
           Landlord at the expense of the Tenant within twenty eight 
           days to procure some other person acceptable to the Landlord 
           to execute a Guarantee in respect of the Tenants obligations 
           contained in this lease in the form set out in the Fourth 
           Schedule hereto
     5.11.      Superior Interests
                __________________
           If this lease shall at any time be an underlease:
           5.11.1.  Any provision for consent or approval of the 
                    Landlord shall be deemed to be subject to the 
                    consent or approval of all superior landlords 
                    and the costs and expenses of obtaining such 
                    consents (whether or not consent is forthcoming) 
                    shall be repaid by the Tenant to the Landlord on 
                    demand
           5.11.2.  To comply with all the Tenants covenants contained 
                    in the Head Lease so far as they relate to the 
                    Demised Premises (but not those expressly assumed 
                    by the Landlord in this Lease or the covenant 
                    contained in clause 5.2.3.1 of the Head lease])
     5.12       Indemnity
                _________
           The Tenant will keep the Landlord fully indemnified against 
           all damages losses reasonable costs expenses proceedings and 
           liabilities purposes properly arising directly or indirectly 
           out of the existence state of repair or user of the Demised 
           Premises any breach of the Tenants covenants herein contained 
           or any failure to comply with the Planning Acts or any other 
           Act and against any liability for any tax levy charge or 
           other fiscal imposition of whatsoever nature including 
           penalties and interest on overdue tax (and penalties for 
           failure to give appropriate notices and information as 
           properly required under the provision of any Acts) for which 
           the Landlord shall be liable as a result of any material 
           development carried out by or on behalf of the Tenant on the 
           Demised Premises and shall on demand pay to the Landlord the 
           amount of any such sum and (if applicable) Interest PROVIDED 
           THAT this clause shall not impose upon the Tenant a greater 
           liability to keep the Demised Premises in good and 
           substantial repair and condition than that imposed by clause 
           5.2 hereof 

6.   THE Landlord COVENANTS with the Tenant as follows:-
     6.1.  Quiet Enjoyment
           _______________
           That the Tenant paying the rents hereby reserved and 
           observing and performing its covenants and conditions 
           contained in this Lease may peaceably and quietly hold and 
           enjoy the Demised Premises without any lawful interruption 
           by the Landlord or any person rightfully claiming through 
           under or in trust for it
     6.2.  To pay the rents reserved by any superior lease (including 
           the Head Lease) for the time being in force on the due dates 
           for payment thereof and to observe and perform all the 
           covenants on its part contained in any superior lease 
           (including the Head Lease) insofar as the same are not to 
           be observed and performed by the Tenant in accordance with 
           the provisions of this Lease
     6.3.  To take reasonable and necessary steps to ensure that the 
           Head Landlord complies with the covenants and agreements 
           on its part contained in the Head Lease to enable the 
           Tenant to have the continued use and enjoyment and benefit 
           of all the obligations contained in such covenants and 
           agreements during the Term so far as such covenants and 
           agreements relate or to affect the Demised Premises
     6.4.  Subject to the Tenant paying to the Landlord the sums due in 
           accordance with Clause 3.3 hereof to keep the Common Parts 
           and all fixtures and fittings therein and additions thereto 
           in a good state of repair and decoration and condition 
           including renewal and replacement of all worn and damaged 
           parts including in particular but without prejudice to the 
           generality of the foregoing to maintain the surface or any 
           roads and pavements and keeps the same properly lit PROVIDED 
           THAT the Landlord shall act fairly and reasonably in carrying 
           out its obligations hereunder at all times and shall manage 
           and maintain the Common Parts economically and efficiently 
           and in  the interests of good estate management 
     6.5.  That the Landlord will forthwith following the destruction or 
           damage of the Demised Premises or the Common Parts due to 
           any defect or deterioration in the Demised Premises or Common 
           Parts which is the direct or indirect result of any fault in 
           the initial design the siting or the method of the 
           construction of the Demised Premises or the Common Parts 
           and/or the building or any part or parts thereof use all 
           reasonable endeavours to reinstate and/or rebuild the 
           Demised Premises or the Common Parts
     6.6.  That the Landlord will use all reasonable endeavours 
           following destruction or damage to the Demised Premises or 
           the Common Parts without delay to obtain all necessary 
           consents and approvals to enable the reinstatement and/or 
           rebuilding to be carried out.
     6.7.  That the Landlord will at all times repair and keep the 
           remainder of the site in good and substantial repair and 
           condition.

7.   PROVIDED ALWAYS AND IT IS HEREBY AGREED AND DECLARED as follows:
     7.1.  Re-entry
           ________
           Notwithstanding and without prejudice to any other remedies 
           and powers herein contained or otherwise available to the 
           Landlord if the rents hereby reserved or any part thereof 
           shall be unpaid for twenty eight days after becoming payable 
           whether formally demanded or not or if any covenant on the 
           Tenant's part or condition contained in this Lease shall not 
           be performed or observed or if the Tenant for the time being 
           (being a Company) shall enter into liquidation whether 
           compulsory or voluntary (save for the purpose of 
           reconstruction or amalgamation whilst solvent) or pass a 
           resolution for winding up (save as aforesaid) or suffer a 
           Receiver to be appointed or being an individual or being more 
           than one individual any one of them shall have a Receiving 
           Order made against him or become bankrupt or if the Tenant 
           (or if there shall be more than one Tenant any of them) shall 
           enter into composition with their or his creditors then and 
           in any such case it shall be lawful for the Landlord at any 
           time thereafter to re-enter upon the Demised Premises or any 
           part thereof in the name of the whole and thereupon this 
           demise shall absolutely determine but without prejudice to 
           any right of action or remedy of the Landlord in respect of 
           any breach non-observance or non-performance of any of the
           Tenant's covenants or any condition herein contained 
     7.2.  Service of Notices
           __________________
           7.2.1.  Any demand or notice to be served on the Tenant or 
                   any Surety hereunder shall be validly served if sent 
                   by first class post addressed to the Tenant or the 
                   Surety respectively at its registered office or its 
                   last known address or at the Demised Premises
           7.2.2.  Any notice to be served on the Landlord shall be 
                   validly served if sent by first class post addressed 
                   to the Landlord at its registered office 
     7.3.  Adjoining land
           ______________
           Nothing in this Lease shall prevent the Landlord and all 
           persons authorised by it without requiring any consent 
           from or making any compensation to the Tenant dealing as 
           it or they may think fit with any land or buildings 
           adjacent or near to the Demised Premises and erecting or 
           suffering to be erected on any part of such land any 
           buildings or structures whatsoever and making any 
           alterations or additions and carrying out any demolition 
           or rebuilding whatsoever which it or they may think fit 
           subject to such buildings alterations or additions not 
           affecting or diminishing the light or air or any right 
           and easement specified in the First Schedule hereto which 
           may now or at any time during the Term be enjoyed by the 
           Demised Premises
     7.4.  No liability in damages
           _______________________
           The Head Landlord shall not in any circumstances incur any 
           liability in respect of damage to person or property or 
           otherwise howsoever by reason of any act neglect default 
           or misfeasance of the Head Landlord or their servants 
           employees agents or independent contractors or by reason 
           of any accidental damage which may at any time be done 
           to the Demised Premises or to any of the goods persons or 
           property of the Tenant or any other person in performance 
           of any services for the Tenant at the Tenant's request
     7.5.  Failure to Perform Obligation
           _____________________________
           The Landlord shall not in any event be liable to the 
           Tenant in respect of any failure of the Landlord to 
           perform any of its obligations to the Tenant hereunder 
           whether expressed or implied (other than those contained 
           in Clause 4 hereof) unless the Tenant has so notified the 
           Landlord and the Landlord has failed within a reasonable 
           time to remedy the same
     7.6.  Statutory Compensation
           ______________________
           Except where any statutory provision prohibits the Tenant's 
           right to compensation being reduced or excluded by agreement 
           the Tenant shall not be entitled to claim from the Landlord 
           on quitting the Demised Premises or any part thereof any 
           compensation under the Landlord and Tenant Act 1954
     7.7.  Exclusion of Riqhts not Granted
           _______________________________
           Nothing herein contained shall operate expressly or impliedly 
           to confer upon or grant to the Tenant any easement right 
           or privilege other than those expressly hereby granted and 
           set out in the First Schedule hereto
     7.8.  If Navstar Systems Limited shall assign this Lease to an 
           assignee (in this clause called "the  assignee") then 
           forthwith upon the completion of an assignment of this lease 
           by the assignee Navstar Systems Limited and Symmetricom Inc 
           shall be released from any further liability under the terms 
           hereof and the Landlord shall at the Tenant's cost execute 
           such deed of release as the Tenant and/or the Surety shall 
           reasonably require Provided that the assignee is not a 
           group company of the original Tenant within the meaning of 
           Section 42 of the Landlord and Tenant Act 1954 
     7.9.  If the Demised Premises any part thereof or any part of the 
           Common Parts over which rights are granted to the Tenant 
           shall at any time be destroyed or damaged due to any defect 
           or deterioration in the Demised Premises or the Common Parts 
           which is the direct or indirect result of any fault in the 
           initial design the siting or the method of construction of 
           the Demised Premises and/or the building or any part or 
           parts thereof or the Common Parts then the rent reserved 
           or a fair and just proportion thereof according to the 
           nature and extent of the damage shall be suspended until 
           the Demised Premises or such parts of the Common Parts over 
           which rights are granted to the Tenant shall be fit for 
           occupation and use or accessible and the Landlord shall 
           forthwith repay to the Tenant such rent paid in advance in 
           respect of the period after the date of such destruction or 
           damage and any dispute regarding the cesser of rent shall be 
           referred to a single arbitrator to be appointed in default 
           of agreement upon the application of either party by the 
           President for the time being of the Royal Institution of 
           Chartered Surveyors under the Arbitration Acts 1950-1979.
     7.10.1.    In this clause 7.10 the following expressions shall 
                have the following meanings:-
           7.10.1.1. "Rent first reserved" means the Rent first reserved 
                     from time to time pursuant to clause 3.1 hereof; 
                     and 
           7.10.1.2. "VAT" means any Value Added Tax or other tax 
                     replacing or supplementing the same from time to 
                     time 
     7.10.2.    In the event of the Head Landlord serving on the Tenant 
                notice under Section 6 of the Law of Distress Amendment 
                Act 1908 or any statutory enactment replacing the same 
                requiring the Tenant to pay the Rent first reserved 
                direct to the Head Landlord then in respect of any 
                period when the Tenant is required to pay the Rent 
                first reserved direct to the Head Landlord the Rent 
                first reserved shall be deemed to be inclusive of 
                any VAT charged assessed or payable thereon
     7.11       If the tenant shall desire to determine the Term at 
                the expiration of the fifth sixth seventh or ninth 
                years thereof then the Tenant shall serve notice on 
                the Landlord as follows:-
     7.11.1     if the tenant shall desire to determine the Term at 
                the expiration of the fifth year of the Term the Tenant 
                shall serve not less than six months previous notice in 
                writing of such desire (such notice to specify that the 
                Term is to determine on the expiration of the fifth year 
                of the Term); and 
     7.11.2.    if the Tenant shall desire to determine the Term at the 
                expiration of the sixth or the seventh or the ninth 
                years of the Term the Tenant shall serve not less than 
                nine months previous notice in writing of such desire 
                (such notice to specify when the Term is to determine)
         and the Term shall thereupon cease at the end of the year of 
         the Term specified in the Tenant's notice and the Landlord 
         shall refund to the Tenant all sums by way of rent paid in 
         advance for any period beyond that date but without prejudice 
         to the rights or remedies of either party against the other 
         in respect of any antecedent claim for breach of covenant

8.   COVENANTS BY SURETY
     ___________________
THE Surety HEREBY COVENANTS with the Landlord in the terms set out
in the Fourth Schedule hereto
IN WITNESS the parties hereto have executed these presents on the date 
specified in Paragraph 1 of the Particulars

                  THE FIRST SCHEDULE above referred to
                  ____________________________________
                      (Rights and Easements Granted)
                      _____________________________
The right (insofar as the Landlord has power to grant the same) for 
the Tenant in common with the Landlord any superior landlords those 
authorised by any of them and all others having the same right to:-
1.   For the purpose only of access to and egress from the Demised 
     Premises to pass and repass with or without vehicles at all 
     times over the roadways comprised in the Site and to use any 
     areas within the Site so allocated for the loading and 
     unloading of vehicles subject always to compliance by the Tenant 
     with all reasonable rules and regulations for the use thereof 
     prescribed from time to time by the Landlord and provided that 
     no obstruction is caused to any car parking spaces on the Site 
2.   To pass and repass on foot only over and along the footways 
     comprised in the Site as a means of access to and egress from 
     the Demised Premises 
3.   Free and uninterrupted passage of services and facilities 
     through the Conduits which are now or may at any time during 
     the Term serve the Demised Premises with the right to construct 
     and maintain new Conduits for the benefit of the Demised 
     Premises (but not to construct new Conduits in on or under 
     any new buildings now or hereafter to be erected on the Site) 
     the right to repair maintain and renew such existing and new 
     Conduits and the right at any time but on Requisite Notice to 
     enter (or in the Landlord's absence but in emergency only to 
     break and enter) the Site subject to the Tenant forthwith 
     making good any damage caused in the exercise of this right 
4.   The right of support and protection for the Demised Premises from 
     the Site and any buildings now or hereafter to be erected on 
     the Site 
5.   Such rights of access to and entry upon the Site as are necessary 
     for the proper performance of the Tenant's obligations hereunder 
     or as may be required to remedy a failure by the Landlord to 
     observe and perform its obligations in this Lease or in the Head 
     Lease 

                  THE SECOND SCHEDULE above referred to
                  _____________________________________
                     (Rights and Easements Excepted)
                     _______________________________
The following rights and easements are excepted and reserved out of 
the Demised Premises to the Landlord any superior landlords and their 
respective tenants and the occupiers of any adjoining or neighbouring 
premises and all other persons authorised by the Landlord or any 
superior landlord or having the like rights and easements:
1.     The free and uninterrupted passage of services and facilities 
through the Conduits which are now or may at any time during the Term 
be in the Demised Premises with the right to construct and maintain 
new Conduits for the benefit of any adjacent or nearby premises (but 
not to construct new Conduits in on or under any buildings now or 
hereafter to be erected on the Demised Premises) the right to repair 
maintain and renew such existing and new Conduits and the right at 
any time but on Requisite Notice to enter (or in the Tenant's absence 
but in emergency only to break and enter) the Demised Premises subject 
to the Landlord forthwith making good any damage caused in the exercise
of this right
2.     The right to build rebuild or execute any other works upon any 
adjacent or nearby premises in such manner as the Landlord may think 
fit subject to the Landlord not affecting or diminishing the access 
or enjoyment of light or air to or in respect of the Demised Premises 
or any right and easement specified in the First Schedule hereto 
SUBJECT to the Landlord giving Requisite Notice and forthwith making 
good any damage caused in the exercise of this right 
3.     The support and protection from the Demised Premises enjoyed by 
buildings now or hereafter to be erected 
4.     The right to build on or into any perimeter wall of the Demised 
Premises and after giving Requisite Notice to enter the Demised 
Premises to place and lay in under and upon the same such footing 
for any intended wall or structure with the foundations therefor as 
the Landlord shall think proper and for such purpose to excavate the 
Demised Premises along the line of the junction between the Demised 
Premises and any adjoining premises And also the right to erect and 
use scaffolding upon the Demised Premises for such purposes PROVIDED 
THAT the Landlord shall (a) not interfere with or restrict the 
Tenant's access to or enjoyment or use of the Demised Premises or 
any part thereof and (b) forthwith make good any damage caused
5.     The right at any time on Requisite Notice to enter (or during 
the Tenant's absence but in emergency only to break and enter) the 
Demised Premises in order to (a) inspect or view the condition of the 
Demised Premises (b) to carry out work upon any adjacent premises and 
(c) to carry out any repairs or other Work or do anything which the 
Landlord and/or the Head Landlord must or may carry out or do under the 
provisions of this Lease or the Head Lease respectively

                  THE THIRD SCHEDULE above referred to
                  ____________________________________
                      (Provisions for Rent Review)
                      ____________________________
1.   In this Schedule the following expressions shall have the 
following meanings:
1.1. "the Rent Review Date" the date specified in the Particulars
1.2. "open market rent" shall mean the best yearly rent for which 
     the Demised Premises could reasonably be expected to be let 
     with vacant possession on the Relevant Review Date (as 
     hereinafter defined) in the open market by a willing lessor 
     to a willing lessee without taking a fine or premium for a term 
     of Ten years from the Relevant Review Date with provisions 
     similar to those contained in the Head Lease for Rent Review 
     every five years and otherwise upon the terms and conditions 
     (save that the extent of the demised premises and rights granted 
     shall be as are herein contained and save also as to the amount 
     of rent) as are contained in this Lease and on the assumption 
     (if not the fact) that the Demised Premises shall be ready for 
     immediate beneficial occupation and that all the Tenant's and 
     the Landlord's covenants shall have been complied with but 
     there being disregarded:
     1.2.1.    any effect on rent of the fact that the Tenant or an
               undertenant may have been in occupation of the Demised 
               Premises 
     1.2.2.    any goodwill attached to the Demised Premises by reason 
               of any trade or business carried on therein by the 
               Tenant or any undertenant
     1.2.3.    any effect of any improvement made by the Tenant for 
               the time being after the date hereof otherwise than 
               in pursuance of an obligation to the Landlord 
     1.2.4.    Any effect of the Works carried out pursuant to a 
               Licence to Carry Out Works dated the 11th day of April 
               1994 made between Strathclyde Regional Council of the 
               first part the Landlord of the second part the Tenant 
               of the third part and the Surety of the fourth part 
2.   From and after the Relevant Rent Review Date the rent first 
     reserved shall be whichever is the higher of:
2.1. the yearly rent operative immediately before the Rent Review 
     Date and
2.2. the open market rent of the Demised Premises (hereinafter called 
     "the new rent")
3.   If the Landlord and the Tenant shall be able to agree the new 
rent or when the new rent shall have been determined in accordance 
with the provisions hereof as the case may be a note of the new rent 
shall be endorsed in the Sixth Schedule to this lease and the 
Counterpart hereof and signed by the parties hereto
4.   If three months before the Rent Review Date the Landlord and the 
Tenant shall not have agreed on the new rent payable from the Rent 
Review Date the Landlord or the Tenant may at any time thereafter 
before the rent shall be agreed between the Landlord and the Tenant 
require an independent Surveyor (hereinafter called  "the  Surveyor") 
to determine the open market rent
5.   The Surveyor may be agreed upon by the Landlord and the Tenant 
and in default of such agreement shall be appointed by the President 
for the time being of the Royal Institution of Chartered Surveyors or 
the person designated by such institution for such purpose on the 
application of the Landlord or the Tenant and any reference hereafter 
to the said President shall be deemed to include a reference to such 
officer
6.1. Notice in writing of his appointment shall forthwith be given 
     by the Surveyor to the Landlord and the Tenant and he shall 
     invite each to submit within a specified period (which shall 
     not exceed four weeks) a valuation accompanied if desired by a 
     statement of reasons
6.2. The Surveyor (who shall be a Chartered Surveyor experienced in 
     the letting and/or valuation of premises of a similar nature to 
     and situate in the same region as the Demised Premises and used 
     for purposes similar to those authorised hereunder at the date 
     of his appointment) shall at the option of the Landlord to be 
     notified to the Surveyor and the Tenant in writing within 21 
     days following the receipt by the Landlord of notice from the 
     Surveyor pursuant to paragraph 6.1 hereof act either as an 
     Arbitrator pursuant to the provisions of the Arbitration Act 
     1950 and 1979 or as an expert valuer whose decision shall be 
     final and binding on all persons who are or who have been 
     parties hereto and if the Surveyor shall act as expert he 
     shall invite each party to make written representations within 
     the period specified in paragraph 6.1 of this Schedule and 
     shall invite each party to make observations on such 
     representations within a further specified period (which shall 
     not exceed four weeks)
6.3. The Surveyor shall give notice in writing of his decision to 
     the Landlord and the Tenant within two months of his appointment 
     or within such extended period as may be reasonable
7.   If the Surveyor shall fail to determine the open market rent 
and give notice thereof within the time and in the manner provided 
or if he shall relinquish his appointment or die or if it shall become 
apparent that for any reason he will be unable to complete his duties 
the Landlord may apply to the said President for a substitute to be 
appointed in his place which procedure may be repeated as many times 
as necessary
8.   In the event that by the Rent Review Date the new rent shall 
not have been agreed or determined (whether or not negotiations shall 
have commenced) the Tenant shall continue to pay rent at the rate of 
the current rent on each day appointed by this Lease for payment of 
rent until the new rent shall have been agreed or determined and 
thereupon the Tenant shall pay to the Landlord as arrears of rent an 
amount equal to the difference between the new rent and the rent 
actually paid for the period since the Rent Review Date together with 
interest thereon at the base lending rate for the time being of the 
Bank of Scotland from the Rent Review Date
9.   The fees of the Surveyor shall be shared as the Surveyor shall 
determine
10.  As respects all periods of time referred to in this Schedule time 
shall be deemed not to be of the essence 
11.  If on the Rent Review Date there shall be in force any act which 
shall restrict interfere with or affect the Landlord's right to revise
the rent hereby reserved in accordance with the terms hereof then the 
Landlord shall be entitled once following each removal or modification 
of such Act to serve notice requiring a review of the said rent
(hereinafter called an "interim notice") upon the Tenant and from 
and after the date of service of such interim notice until the end of 
the Term the rent shall be increased to whichever is the higher of the 
open market rent at the date of service of the interim notice and the
rent payable immediately prior thereto and the provisions of this 
Schedule shall apply accordingly with the substitution of the said 
date of service for the Rent Review Date 

                  THE FOURTH SCHEDULE above referred to
                  _____________________________________
The Surety COVENANTS with the Landlord:
1.   That if at any time during the Term the Tenant shall default in 
payment of any of the rents reserved by this lease on the due dates 
or in observing or performing any of the covenants and conditions 
contained in this Lease which the Tenant is obliged to observe and 
perform the Surety will pay the rents or observe or perform the 
covenants or conditions in respect of which the Tenant shall have 
defaulted notwithstanding any time or indulgence granted by the 
Landlord to the Tenant or that the Tenant may have ceased to exist or 
any other act or thing whereby but for this provision the Surety would 
have been released
2.   That if the liquidator or trustee in bankruptcy shall disclaim 
this Lease the Surety will at the request of the Landlord within three 
months after such disclaimer take from the Landlord a Lease of the 
Demised Premises for a term equal to the residue of the Term which 
would have remained had there been no disclaimer at the same rent and 
subject to the same covenants and conditions as are reserved by and 
contained in this Lease (except the requirement that a Surety join 
therein) such lease to take effect from the date of such disclaimer and 
in such case the Surety shall pay the reasonable costs of the Landlord  
in the preparation of such new Lease and execute and deliver a 
counterpart of it to the Landlord
3.   In this Schedule the expression "the Tenant" shall mean only 
Navstar Systems Limited and not any and every person or persons 
company or corporation in whom the term shall for the time being be 
vested
4.   The covenants and guarantees contained in clauses 1 and 2 of 
this Schedule shall (subject to the provisions of clause 3 of this 
Schedule) have effect throughout the Term and also throughout any 
period thereafter during which the Tenant shall occupy the Demised 
Premises and the said covenants and guarantees shall relate to any 
sums greater than the rents hereby reserved which the Tenant shall 
become liable to pay under the terms hereof or of any subsequent deed 
or licence supplemental to this Lease save and except any subsequent 
deed or licence supplemental to this Lease which has the effect of 
extending the contractual term

                  THE FIFTH SCHEDULE above referred to
                  ____________________________________
                 (Deeds to which the demise is subject)
                 ______________________________________
The covenants restrictions reservations conditions and other matters 
contained or referred to in the Property Register and entries numbered 
1 to 4 inclusive of the Charges Register of Title Number NN.85259

                  THE SIXTH SCHEDULE above referred to
                  ____________________________________
                        Memoranda of rent review:
                        _________________________
The rent payable from the first review date specified in the 
particularshas been agreed as Pounds (            ) per annum


                                          Signed______________________
                                          duly authorised signatories 
                                          of the Landlord/Tenant/Surety

The rent payable from the Second review date has been agreed as 
Pounds (           per annum)


                                          Signed_____________________
                                          duly authorised signatories 
                                          of the Landlord/Tenant/Surety

Executed as a Deed by NAYSTAR SYSTEMS 
LIMITED was hereunto affixed (but this 
Deed was not delivered until the date 
hereof) acting by its Secretary and a
Director or two Directors

        Director

        Secretary/
        Director

THE COMMON SEAL OF SYMMETRICON INC 
was hereunto affixed (but this Deed) 
was not delivered until the date 
hereof) in the presence of:-


               Director


              Secretary


                            SYMMETRICOM, INC. 
                     formerly Sillcon General, Inc.




                      To:          Andrea Collins
                      From:        Jane Williamson

                      RE:          Lease
                                   Mansard Close  Northampton

                      Attached please find the duly signed and 
                      sealed above mentioned lease agreement.

                      This is being returned to you via Federal 
                      Express on this date.

                      A copy of this lease agreement has been 
                      filed in our files at Telecom Solutions/ 
                      Symmetricom, Inc.




cc:    Paul Risinger
       Scott Kamsler 





        Date   APril 22, 1994



M Duckham Esq             Oxford House         Telephone (0604) 230400
Navstar Ltd               Cliftonville         Fax (0604)20956 & 230426
Royal Oak Way             Northampton NN1 5PN  DX 12413 Northampton
DAVENTRY                  Direct Fax Line No:  (0604) 32102
Northants  NN11 5PJ



Our Ref:   GLG/sh.18.9
Your Ref:
Date:      18th April 1994



Dear Mike

Mansard Close Northampton
_________________________

I enclose the underlease for sealing by Navstar and Symmetricom. I 
have amended the attestation clause as I believe that Navstar does 
not have a seal.

Can you please return the underlease to me duly sealed and undated 
as soon as possible.





G L GILBERT

Enc





















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