EXHIBIT 10.2

                                 LOAN AGREEMENT



                                February 17, 2000


Signal Technology Corporation
222 Rosewood Drive
Danvers, MA 01923

         Attention: George E. Lombard, Chairman and Chief Executive Officer

Dear Sirs:

          This loan  agreement  (the "Loan  Agreement")  describes the terms and
conditions  under which Signal  Technology  Corporation  ("Signal")  is herewith
lending to  LogiMetrics,  Inc. (the  "Company") an aggregate of up to $2,000,000
(the  "Loan")  for  working  capital  and  other  general  corporate   purposes.
$1,000,000  of the  Loan  will be  advanced  upon  completion  of  Signal's  due
diligence  examination of the New York Business (as defined  below),  subject to
the  simultaneous  closing  of the Legacy  Loan (as  defined  below).  All other
amounts to be  advanced  under the Loan shall be  advanced  in  accordance  with
Schedule II attached to the Promissory Note dated the date hereof by the Company
in favor of Signal.

          As a condition to Signal's obligation to make the Loan, on or prior to
the date hereof,  certain  current  institutional  investors of the Company will
lend an aggregate  of  $1,000,000  to the Company for working  capital and other
general corporate  purposes (the "Legacy Loan").  Approximately  $610,000 of the
Legacy Loan has been advanced since December 2, 1999. The remaining  $390,000 of
the Legacy Loan will be advanced as follows: $50,000 on the date Signal advances
its first  $1,000,000,  and thereafter at the rate of $34,000 for every $100,000
Signal advances, at such times as Signal makes such advances.

          To induce Signal to make the Loan,  the Company is hereby  granting to
Signal  an  exclusive  option  to  purchase  all of the  assets  of the New York
Business (as defined  below).  The option shall be  exercisable by Signal solely
upon the failure of the Company and Signal,  negotiating in good faith, to enter
into the definitive  agreements  referred to in the Letter of Intent (as defined
below)  by the end of the  Exclusivity  Period  (as  defined  in the  Letter  of
Intent). The option granted hereby shall expire upon the earlier to occur of (i)
thirty (30) days after the payment in full of all amounts  owing to Signal under
the  Promissory  Note or (ii) December 31, 2000.  The option  purchase  price is
$2,000,000,  less (i) the  amount of any  indebtedness  of the  Company  owed to
Signal, which shall be forgiven (except to the extent of the 5% indemnity escrow
referred to below), (ii) an amount which, in the aggregate, is equal to the bank

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and other funded indebtedness of the Company assumed by Signal (but Signal would
agree to assume other  current  liabilities  incurred in the ordinary  course of
business).  In the event that the number of $2,000,000,  less the deductions set
forth above,  is a number that is less than zero,  then the Company shall pay to
Signal such amount in order to bring the amount of the  calculation  to zero, so
that Signal's cost does not exceed $2,000,000. The sale of the New York Business
will be subject to, among other things,  (i) the Company  obtaining  approval of
such sale  from its  shareholders,  and (ii) the  negotiation,  preparation  and
execution of an asset purchase  agreement and such other relevant  documentation
governing the terms and conditions of such sale  (collectively,  the "Definitive
Agreements").  For purposes of this letter  agreement,  the "New York  Business"
shall mean the business  located at 50 Orville Drive,  Bohemia,  New York 11716.
The  Definitive  Agreements  will  include,  among other  things,  (a) customary
representations  and  warranties by the Company  (which will expire on the first
anniversary of the closing (the "Survival  Period") except for certain  standard
exceptions,  such as with  respect to  authority,  title,  taxes,  environmental
liabilities,  ERISA  liabilities  and other  identified  claims and  liabilities
(collectively,  the  "Standard  Exceptions"));  (b)  an  escrow  to  secure  the
representations,  warranties  and  covenants  of the  Company  until  the  first
anniversary of the closing  (although  Signal might consider a shorter  survival
period  based on its  operation  of the New York  Business  contemplated  by the
Management  Agreement  referred to in the Letter of  Intent),  such escrow to be
accomplished by the forgiveness of 95% of the indebtedness outstanding under the
Promissory Note; (c) a  non-competition  agreement by the Company and its senior
management  and normal and  customary  indemnification  by the  Company  for any
breach of  representation  or  warranty  by it,  provided  that,  except for the
Standard Exceptions, there will be no such indemnification for claims unless the
total exceeds two percent (2%) of the purchase  price,  and,  provided  further,
that except for the Standard  Exceptions,  there shall be no indemnification for
amounts in excess of five  percent  (5%) of the purchase  price,  unless  Signal
discovers  something  during its due diligence  investigation  that causes it to
reasonably  believe that such amount is  inadequate,  which  indemnity  shall be
secured by the  post-closing  escrow of five percent (5%) of the purchase price,
as noted above,  which shall be released  immediately  after the Survival Period
except for amounts necessary to provide security for claims previously made.

          To induce  Signal to make the Loan,  the  Company  and Signal are also
entering into a non-binding (except for certain specified  provisions) letter of
intent of even date  herewith (the "Letter of Intent"),  which  provides for the
merger of a wholly-owned subsidiary of Signal into the Company ("the Merger").

          Between now and the closing of the Merger,  the Company  will  conduct
its  business in the normal and  ordinary  course.  Pending  such  closing,  the
Company will provide  reasonable  access to the Company's and its  subsidiaries'
books and  records to Signal  and those of its  employees,  representatives  and
advisors  who need  such  access  in order to  enable  Signal  to  complete  its
financial and backlog due diligence  investigation  contemplated  above.  Signal

<PAGE>

hereby acknowledges and agrees that any information disclosed to Signal and such
employees,  representatives  and advisors in connection  with such access to the
Company's   and  its   subsidiaries   books  and   records  is  subject  to  the
confidentiality  provisions  contained  in Section 8 of the Letter of Intent and
the existing  Confidentiality  Agreement  between  Signal and the Company  dated
December 14, 1999.

          Simultaneously  herewith,  the Company is  delivering  to Signal (i) a
Negotiable  Secured  Senior  Subordinated   Promissory  Note  in  the  aggregate
principal  amount  of  $2,000,000  (the  "Note"),  substantially  in the form of
Exhibit A attached  hereto,  registered in the name of Signal,  (ii) an executed
counterpart  of an Amendment No. 2 to the Second  Amended and Restated  Security
Agreement,   Intercreditor   Agreement,   Waiver  and  Consent  (the   "Security
Agreement"), substantially in the form of Exhibit B attached hereto, granting to
Signal the security interests in the collateral described therein,  (iii) one or
more executed Financing  Statements on Form UCC-1 or assignments of all existing
Financing  Statements (the "Financing  Statements")  evidencing the grant of the
security  interests pursuant to the Security  Agreement,  (iv) executed consents
from all lenders of the Company whose consent is required in connection with the
transactions  contemplated  hereby,  (v) a copy of an executed  extension letter
from North Fork Bank extending the maturity date of the  $1,930,000  Reduced and
Extended Revolving Credit Note, dated as of September 1, 1999, to at least [June
30],  2000, and (vi) a secretary's  certificate  covering such matters as Signal
has requested.  The Company hereby represents and warrants to Signal on the date
hereof that (i) it is duly  incorporated,  validly existing and in good standing
in the  jurisdiction  of its  incorporation,  (ii) it owns or holds all material
licenses  and permits  necessary  for the conduct of its  business as  presently
conducted,  (iii) it has the authority to enter into and perform its obligations
under  this  Agreement,  the Note,  the  Security  Agreement  and the  Financing
Statements,  and (iv) each of this Agreement,  the Note, the Security  Agreement
and the  Financing  Statements  (A) has been duly  authorized  by all  necessary
corporate  action on the part of the  Company,  (B) has been duly  executed  and
delivered  by the  Company,  and (C)  constitutes  the legal,  valid and binding
obligation of the Company,  enforceable in accordance with its terms, subject to
bankruptcy,  insolvency,  fraudulent  transfer,  reorganization,  moratorium and
similar laws of general applicability relating to or affecting creditors' rights
and to general equity principles.

          The  Company  hereby  agrees  that it shall  reimburse  Signal for its
reasonable  out-of-pocket  expenses  (including  reasonable  attorneys' fees and
disbursements)  incurred in connection with the negotiation and documentation of
the Loan upon  presentation  of a reasonably  detailed  invoice  specifying  the
amount of such expenses.

          Together  with  the  Note,  the  Security  Agreement,   the  Financing
Statements and the Letter of Intent,  this Loan  Agreement  comprises the entire
agreement  among the Company and Signal  regarding  the subject  matter  hereof,
there being no other written, oral or other agreements or understandings between
them with respect to the subject matter hereof or thereof.

<PAGE>

          This letter agreement may be executed in  counterparts,  each of which
shall be deemed an original and all of which together  shall  constitute one and
the same  instrument.  This letter agreement shall be governed by, and construed
in accordance  with, the internal laws of the State of New York,  without regard
to the choice of law provisions thereof.

          This letter and the terms and  provisions  hereof  will  automatically
terminate  upon the earlier to occur of (i) the closing of the Merger,  (ii) the
closing  of the  purchase  of the New York  Business  or (iii) the date which is
thirty  (30) days after  payment in full by the Company to Signal of all amounts
owed to Signal hereunder and under the Note. In addition, Signal and the Company
may terminate this letter by mutual written consent at any time.


                     [Rest of Page Intentionally Left Blank]


<PAGE>

If the  foregoing  accurately  reflects  our  mutual  understanding,  please  so
indicate by executing a counterpart of this letter agreement and returning it to
the undersigned.

                                                Very truly yours,

                                                LOGIMETRICS, INC.


                                                 By: /s/Norman M. Phipps
                                                     ___________________________
                                                     Norman M. Phipps, President
                                                     and Chief Operating Officer

ACCEPTED AND AGREED:

SIGNAL TECHNOLOGY CORPORATION


By:  /s/George E. Lombard
     ______________________________
     George E. Lombard, Chairman
     and Chief Executive Officer


Dated:  February 17, 2000

<PAGE>

                                                                     Exhibit A

                             Form of Promissory Note

                     NEGOTIABLE SECURED SENIOR SUBORDINATED
                                 PROMISSORY NOTE

$2,000,000                                                  Final Maturity Date:
                                                            December 31, 2000


          FOR VALUE RECEIVED,  LogiMetrics,  Inc., a Delaware  corporation  (the
"Maker"),  hereby promises to pay to the order of Signal Technology  Corporation
or its successors and assigns (the  "Holder"),  at its corporate  offices at 222
Rosewood Drive,  Danvers,  MA 01923, or at such other location as the Holder may
designate from time to time,  the aggregate  unpaid amount of all loans (each, a
"Loan") made by the holder to the Maker hereunder. Each Loan shall mature and be
due and payable,  together with all interest accrued thereon, in lawful money of
the United States of America on or before December 31, 2000,  or on demand under
certain circumstances as specified herein.

          The Maker promises to pay interest on the unpaid  principal  amount of
each  Loan  from the date  such Loan is made  until  its  maturity  (whether  by
acceleration  or otherwise),  at the rate of 10% per annum,  such interest to be
paid on maturity.

          1. If the Maker fails to pay any amount  hereunder when due,  interest
shall  thereafter  accrue on such overdue  amount at a rate of interest equal to
the lesser of:  (i) 18% per annum;  or (ii) the  highest  rate  permitted by law
until paid in full.  Interest  hereunder  shall be  calculated on the basis of a
360-day year for the actual number of days elapsed.

          2. The  maximum  aggregate  principal  amount  of the Loans to be made
hereunder  shall be  $2,000,000.  The Holder is  authorized  to record all Loans
evidenced  hereby  in its  records  (including,  but not  limited  to,  the grid
attached hereto as Schedule 1), and such entries shall be conclusive evidence of
amounts outstanding hereunder absent manifest error.

          3.  On  the  date  hereof,  the  Holder  is  advancing  to  the  Maker
$1,000,000.  The remaining  Loans hereunder shall be made in accordance with the
loan schedule set forth on Schedule II hereto.

          4. The Maker may prepay any Loan made  hereunder at any time, in whole
or in part, without premium or penalty. The Maker shall prepay all Loans in full
to the Maker within five (5) Business Days after:  (i) the  consummation  of any
public or private  offering by the Maker of its equity  securities or securities
convertible into or exchangeable for its equity securities pursuant to which the
Maker  receives  gross  proceeds  (before the  deduction  of offering  expenses,
discounts  and  commissions)  of at least Seven  Million Five  Hundred  Thousand
Dollars  ($7,500,000);  or (ii) the sale or transfer, in a single transaction or
in a series of related transactions,  of all or substantially all of the Maker's
assets,  or the merger,  consolidation,  reorganization  or  dissolution  of the
Maker,  or  the  sale,  in a  single  transaction  or  in a  series  of  related
transactions,  of a majority of the Maker's  voting capital stock (whether newly
issued or from  treasury,  or  previously  issued and then  outstanding,  or any
combination  thereof),  in each case other  than in a  transaction  with  Signal
contemplated  by the  Letter of Intent  (the  "Letter of  Intent")  of even date
herewith  between  Signal  and the  Company  (any of such  events,  a  "Disposal
Event"), or the execution by the Maker of any letter of intent or like agreement
with respect to the consummation of a Disposal Event. In addition,  in the event

<PAGE>

the  Maker  executes  a letter of intent or like  agreement  with  respect  to a
Disposal Event that is an Acquisition  Transaction  (as defined in the Letter of
Intent), or with respect to any other Acquisition Transaction, during the period
commencing  on such date as is 46 days  following  date of Letter of Intent  and
continuing  through and  including  such date as is 120 days  following  date of
Letter of Intent,  the Maker shall,  on the date it prepays all Loans in full in
accordance  herewith,  pay to the Holder a  prepayment  penalty in the amount of
$100,000.  As used herein,  "Business Day" means a day, other than a Saturday or
Sunday,  on which  commercial  banks in New York  City are open for the  general
transaction of business.

          5. At any time while Loans are outstanding hereunder, the Holder shall
have the right during normal  business hours to examine the books and records of
the Maker,  to make  copies,  notes,  and  abstracts  therefrom,  to discuss the
Maker's affairs with the officers,  directors, key employees, and accountants of
the Maker and, no more than once,  to make or cause an  independent  examination
and/or audit (at its expense) of the books and records of the Maker.

          6. The Maker shall pay to the Holder the  reasonable  attorneys'  fees
and  disbursements and all other  out-of-pocket  costs incurred by the Holder in
order to collect  amounts due and owing under this Note.  All payments  received
shall be applied, first, to the costs of collection, second, to unpaid interest,
and third, to principal.

          7. No delay or  failure on the part of the  Holder in  exercising  any
power,  right or remedy  hereunder  shall operate as a waiver of any such power,
right or remedy; nor shall any single or partial exercise of any power, right or
remedy preclude any other or further exercise of such power, right or remedy, or
the exercise of any other power, right or remedy, and no waiver whatsoever shall
be valid  unless in writing,  signed by the Holder,  and then only to the extent
expressly set forth therein.  No remedy is exclusive of any other remedy and all
remedies shall be cumulative to the maximum extent  permitted by applicable law.
The Maker hereby waives presentment,  demand for payment,  diligence,  notice of
dishonor  and all other  notices  or demands in  connection  with the  delivery,
acceptance, performance, default or endorsement of this Note.

          8. This Note is one of the Notes referred to in Amendment No. 2 to the
Second Amended and Restated Security Agreement,  Intercreditor Agreement, Waiver
and Consent,  dated the date hereof,  among the Maker, Cramer Rosenthal McGlynn,
LLC,  as Agent (the  "Agent"),  and the other  parties  thereto  (the  "Security
Agreement")  and is  secured  by the  Collateral  (as  defined  in the  Security
Agreement).  The Security Agreement grants the Agent on behalf of the Holder and
the other parties  thereto  certain rights with respect to the  Collateral  upon
certain defaults  specified therein and sets forth the related priorities of the
Holder and the other parties thereto with regard to such Collateral.

          9.  If  any  of  the  following  events  or  circumstances   (each  an
"Acceleration Event") shall occur:

          (a) the Maker shall fail to pay any amount of  principal,  interest or
other  amount (if any)  within ten (10) days of the date on which such amount is
due and payable hereunder; or

          (b) an Event of  Default  under  the  Security  Agreement  shall  have
occurred  and be  continuing  or the Maker  shall fail to cure any breach of its
other covenants,  agreements or obligations hereunder within ten (10) days after
written notice by the Holder to the Maker specifying such breach; or

<PAGE>

          (c) any  representation or warranty made by the Maker herein or in the
Security Agreement shall have been false in any material respect when made; or

          (d) the Maker shall make an  assignment  for the benefit of creditors,
or shall petition or apply for the appointment of a trustee or other  custodian,
liquidator or receiver of the Maker or of any substantial part of its assets, or
shall  commence  any case or other  proceeding  relating to its assets under any
bankruptcy,  reorganization,  arrangement,  insolvency,  readjustment  of  debt,
dissolution or liquidation or similar law of any jurisdiction, or shall take any
corporate action to authorize or in furtherance of any of the foregoing;  or any
such petition or application shall be filed or any such case or other proceeding
shall be commenced against the Maker, and the same shall not have been dismissed
within 60 days of the filing or commencement thereof or the Maker shall indicate
its approval thereof,  consent thereto or acquiescence  therein;  or a decree or
order shall be entered  appointing  any such trustee,  custodian,  liquidator or
receiver  or  adjudicating  the Maker  bankrupt  or  insolvent,  or  approving a
petition in any such case or other  proceeding,  or a decree or order for relief
shall be entered in respect of the Maker in an  involuntary  case under any such
bankruptcy or insolvency laws; or

          (e) the Maker shall take any corporate  action to liquidate its assets
or dissolve,  or shall take any corporate action to consolidate or merge with or
into any other  corporation  or  business  entity  unless the Maker shall be the
surviving  legal entity of such  consolidation  or merger or the surviving legal
entity of such  consolidation  or merger shall have assumed in full by a written
instrument  the  obligations  under and in respect of this Note,  other than any
such  corporate   action  in  connection  with  the   transaction   with  Signal
contemplated by the Letter of Intent; or

          (f) without the prior written  consent of the Holder,  the Maker shall
have  incurred  indebtedness  for borrowed  money (other than  indebtedness  for
borrowed  money,  together with interest  thereon,  existing on the date hereof)
which is or will be senior or pari passu to its indebtedness  hereunder,  except
for  indebtedness  incurred by the Maker pursuant to the Legacy Loan referred to
in the Loan  Agreement  of even date  herewith  between the Maker and the Holder
(the "Loan Agreement");

then, the Holder at its option at any time thereafter  during the continuance of
an Acceleration  Event may declare the entire and unpaid  principal of this Note
and all  interest,  fees and  expenses (if any) payable on or in respect of this
Note and the obligations  evidenced  hereby due and payable,  and the same shall
thereupon   forthwith   become  and  be  due  and  payable  to  the  Holder  (an
"Acceleration")  without presentment,  demand, protest, notice of protest or any
other formalities of any kind, all of which are hereby expressly and irrevocably
waived by the Maker,  provided that in the event of an Acceleration  Event under
Section 9(d) hereof all such amounts  shall  become and be  immediately  due and
payable, and  an  Acceleration  shall be deemed for all purposes  hereof to have
occurred, automatically and without any requirement of notice from the Holder.

          10.  The Maker  will not,  by  amendment  of its  Charter  or  through
reorganization, consolidation, merger, dissolution, issuance of capital stock or
sale of  treasury  stock  (otherwise  than upon  exercise of  conversion  rights
hereunder) or sale of assets,  or by any other  voluntary act or deed,  avoid or
seek to avoid the material  performance  or observance of any of the  covenants,
stipulations  or  conditions  in this Note to be  observed or  performed  by the

<PAGE>

Maker. The Maker will at all times in good faith assist,  insofar as it is able,
in the carrying out of all of the provisions of this Note in a reasonable manner
and in the taking of all other action which may be necessary in order to protect
and preserve the rights of the Holder set forth herein.

          11. This Note shall be binding upon the Maker and its  successors  and
assigns.  This Note shall be governed by, and construed in accordance  with, the
internal  laws of the  State of New York  pursuant  to  Section  15-1402  of the
General  Obligations  Law of such state.  The Maker  irrevocably  submits to the
exclusive  jurisdiction  of the  courts of the State of New York and the  United
States  District Court for the Southern  District of New York for the purpose of
any suit,  action,  proceeding  or  judgment  relating to or arising out of this
Note.  Service of process in connection with any such suit, action or proceeding
may be served on the Maker  anywhere  in the world by any method  authorized  by
law. The Maker irrevocably consents to the jurisdiction of any such court in any
such suit, action or proceeding.  The Maker irrevocably  waives any objection to
the  laying of venue of any such  suit,  action or  proceeding  brought  in such
courts and irrevocably waives any claim that any such suit, action or proceeding
brought in any such court has been brought in an inconvenient forum.

<PAGE>

          12.  No  modification,  alteration,  waiver  or  change  of any of the
provisions  hereof shall be effective  unless in writing and signed by the Maker
and the Holder and, then, only to the extent set forth in such writing.

ATTEST:                                     LOGIMETRICS, INC.



_____________________                       _____________________________
Name:                                        By:     Norman M. Phipps
                                                      Title:  President


Dated:  February 17, 2000

<PAGE>



                                   Schedule 1




                                         Date of                 Notation
             Amount of Loan              Advance                  Made By
    ------------------------ ----------------------- ------------------------

    ------------------------ ----------------------- ------------------------
    ------------------------ ----------------------- ------------------------

    ------------------------ ----------------------- ------------------------
    ------------------------ ----------------------- ------------------------

    ------------------------ ----------------------- ------------------------
    ------------------------ ----------------------- ------------------------

    ------------------------ ----------------------- ------------------------
    ------------------------ ----------------------- ------------------------


<PAGE>


                                   Schedule II

<PAGE>

                                    Exhibit B

             Form of Amendment No. 2 to Second Amended and Restated
        Security Agreement, Intercreditor Agreement, Waiver and Consent

       AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED SECURITY AGREEMENT,
                  INTERCREDITOR AGREEMENT, WAIVER AND CONSENT


          Amendment No. 2, dated as of February 17, 2000 (this  "Amendment")  to
the Second Amended and Restated  Security  Agreement,  Intercreditor  Agreement,
Waiver And Consent dated March 7, 1996, as previously amended and restated as of
July 29,  1997 and on or about  August  31,  1999,  and as  further  amended  by
Amendment No. 1 thereto,  dated as of December 2, 1999 (the "Agreement"),  among
LOGIMETRICS,  INC., a Delaware corporation ("LogiMetrics"),  and mmTech, Inc., a
New  Jersey   corporation   ("mmTech"  and,  together  with   LogiMetrics,   the
"Borrowers"),  Cramer Rosenthal  McGlynn,  LLC, as Agent (in such capacity,  the
"Agent") for itself and the other Holders listed on the signature  pages hereto,
and any other  persons  becoming  Holders  from time to time.  Pursuant  to this
Amendment,  SIGNAL TECHNOLOGY CORPORATION, a Delaware corporation ("Signal"), is
hereby added as a Holder party hereto, as hereinafter set forth, effective as of
the Effective  Date, as  hereinafter  defined).  Capitalized  terms used but not
defined herein shall have the meaning set forth in the Agreement.

          WHEREAS the Borrowers are presently indebted to the various Holders in
respect of certain Notes, Class A Debentures,  Class B Debentures and/or Class C
Debentures as defined in, subject to and secured by the Agreement (collectively,
the "Junior Indebtedness");

          WHEREAS, in addition,  the certain Holders listed on Schedule A hereto
have made and, subject to this Amendment and certain related undertakings by the
Borrowers  and  Signal,  intend  to make  additional  loans  from to time in the
aggregate principal amount of $1,000,000 (the "Legacy Loans", which are the same
as the "New  Loans" as  defined in  Amendment  No. 1 to the  Agreement),  in the
principal  amounts set forth opposite each Holders name on such Schedule A, each
Legacy Loan being or to be evidenced by a Supplemental Negotiable Secured Senior
Subordinated  Promissory  Note  substantially  in the form  attached  hereto  as
Exhibit A (the "Legacy Notes",  which are the same as the "New Notes" as defined
in Amendment No. 1 to the  Agreement) and secured by and subject to the terms of
the Agreement;

          WHEREAS,  simultaneously  herewith,  the  LogiMetrics  and  Signal are
entering into (i) a Letter of Intent (the "Signal Letter of Intent") pursuant to
which the parties intend to consummate a reverse  merger of  LogiMetrics  into a
wholly-owned  subsidiary  of Signal,  (ii) a Loan  Agreement  (the  "Signal Loan
Agreement")  pursuant to which Signal will make loans to  LogiMetrics  up to the
aggregate  principal  amount of $2,000,000 (the "Signal  Loans"),  $1,000,000 of
which is to be advanced on or about the date hereof and the  remainder  is to be
advanced  from time to time  thereafter,  pursuant to and  evidenced by a single
Negotiable  Secured  Senior  Subordinated   Promissory  Note  in  the  aggregate
principal  amount of $2,000,000,  substantially  in the form attached  hereto as
Exhibit B (the  "Signal  Note"),  with such  Signal  Loans and Signal Note to be
secured by the  Agreement  (as  hereby  amended)  on terms  senior to the Junior
Indebtedness  and to the rights,  preferences  and priorities as are accorded to
any of the Junior Indebtedness under the Agreement, pari passu and pro rata with
the Legacy Loans and to the rights,  preferences  and priorities as are accorded
to the  Legacy  Loans  under the  Agreement,  and junior to any  amounts  now or

<PAGE>

hereafter  owing to the  Agent,  solely  in its  capacity  as Agent and not as a
Holder,  and to the rights,  preferences  and priorities as are accorded to such
indebtedness under the Agreement,  and (iii) a Management Agreement (the "Signal
Management   Agreement")  pursuant  to  which  Signal  will  immediately  assume
management of substantially all of the business assets of LogiMetrics located in
Bohemia,  New York (as set forth in the Signal  Management  Agreement,  the "New
York  Business  Assets")  and will  relocate  the New York  Business  Assets  to
Florida,  and Signal shall have rights under the Signal Management Agreement and
the Signal Loan Agreement to acquire the New York Business  Assets under certain
circumstances if the above-referenced reverse merger is not consummated;

          WHEREAS,  subject to the terms and conditions of this  Amendment,  the
parties hereto wish to (i) waive all existing Events of Default under the Junior
Indebtedness  and the Legacy  Loans,  (ii)  consent to the Signal  Loans and the
Signal  Note,  and agree that the Signal  Loans and the  Signal  Notes  shall be
subject to and secured by the Agreement  (as amended  hereby) on terms senior to
the Junior  Indebtedness  and to the rights,  preferences  and priorities as are
accorded to any of the Junior  Indebtedness under the Agreement,  pari passu and
pro rata with the Legacy Loans and to the rights,  preferences and priorities as
are accorded to the Legacy Loans under the Agreement,  and junior to any amounts
now or hereafter owing to the Agent,  solely in its capacity as Agent and not as
a Holder,  and to the rights,  preferences and priorities as are accorded to the
such  indebtedness  under the Agreement,  (iii) consent to the Signal Management
Agreement,  including,  without  limitation,  the provisions  therein (or in the
Signal Loan Agreement) for the management,  relocation and acquisition by Signal
of the New York Business Assets and, in connection  therewith,  agree to release
the Agent's lien and  security  interest in the New York  Business  Asset in the
event that Signal acquires the same pursuant to such provisions; and

          WHEREAS the parties hereto wish to memorialize such waivers,  consents
and agreements by this Amendment,

          NOW, THEREFORE,  in consideration of the above premises and other good
and  valuable  consideration,  the receipt and  sufficiency  of which are hereby
acknowledged,  and  subject  to the terms  and  conditions  hereof,  each of the
parties hereto, effective as of the Effective Date (defined below), hereby:

          1. Waives all existing Events of Default under the Junior Indebtedness
and the Legacy Loans,  including any occasioned by the entry by LogiMetrics into
the Signal Letter of Intent, the Signal Loan Agreement,  the Signal Note and the
Signal Management  Agreement,  and the other documents referred to therein to be
entered into simultaneously therewith (the "Signal Transaction Documents");

          2. Gives its consent to the Signal Loans to be issued  pursuant to the
Signal Loan  Agreement  and to be evidenced by the Signal  Note,  provided  that
Signal does becomes, and by its signature below Signal hereby agrees to and does
become,  a party to the  Agreement  as a Holder with respect to the Signal Loans
and  accepts  and agrees to be bound by all of the terms and  conditions  of the
Agreement  (as amended  hereby)  and,  without  limiting the  foregoing,  hereby
unconditionally  appoints the Agent as its agent under and pursuant to the terms
of the Agreement for all purposes of thereof;

<PAGE>

          3. Agrees that the Signal Loans and the Signal Note shall hereafter be
and shall be deemed to be subject  to and  secured  by the  Agreement,  and with
respect  to  the  Collateral  shall  rank  (a)  senior  to  all  of  the  Junior
Indebtedness  and to the rights,  preferences  and priorities as are accorded to
any of the Junior Indebtedness under the Agreement,  (b) pari passu and pro rata
with the Legacy  Loans and to the  rights,  preferences  and  priorities  as are
accorded  to any of the Legacy  Loans  under the  Agreement,  and (c) junior and
subject to any amounts now or hereafter owing by the Borrowers or any of them to
the  Agent  under  the  Agreement,  solely in its  capacity  as Agent  under the
Agreement and not as a Holder, and to the rights,  preferences and priorities as
are accorded to such indebtedness under the Agreement ;

          4. Gives its consent to  management by Signal of the New York Business
Assets, the relocation by Signal of the New York Business Assets to Florida, and
the acquisition by signal of the New York Business  Assets,  all pursuant to the
terms of the Signal Management  Agreement and/or the Signal Loan Agreement,  and
hereby  further  agrees  that  the lien and  security  interest  in the New York
Business  Assets  arising  under the Agreement  shall be and be deemed  released
without  further action upon the  acquisition by Signal of the New York Business
Assets in accordance  with the terms of the Signal  Management  Agreement or the
Signal  Loan  Agreement,  provided  that,  until  such time as  Signal  actually
acquires  title to the New York  Business  Assets  pursuant  to the terms of the
Signal Management Agreement or the Signal Loan Agreement, LogiMetrics and Signal
shall take all actions necessary or reasonably  requested by the Agent to ensure
the continued  perfection at all times of the lien and security  interest of the
Agent in the New York  Business  Assets,  including  the execution and filing of
appropriate UCC financing statements in Florida and the separate  identification
and  non-commingling  with Signal's own assets of the New York Business  Assets,
and (subject to Signal's rights under the Signal Management Agreement and Signal
Loan  Agreement)  Signal  hereby agrees to hold and manage the New York Business
Assets in trust for the Agent and the Holders, and

          5. Agrees that the Agreement is hereby amended to reflect the waivers,
consents  and  agreements  set  forth  herein  above,  and that any  conflicting
provisions  of the Agreement are hereby  superseded,  but,  solely to the extent
necessary to give effect to this Amendment,  and without limiting the generality
of this Section 3, the following provisions shall be amended as follows:

               (a) All references in the Agreement to the term "Agreement" shall
     mean the  Agreement  as amended and  supplemented  through the date hereof,
     including as amended and supplemented  hereby, as the same may hereafter be
     further amended,  supplemented or otherwise modified in accordance with its
     terms;

               (b) All  references  in the  Agreement  to the words  "Loans" and
     "Notes" shall mean,  respectively,  only the Loans and Notes other than the
     Legacy Loans and Legacy Notes,  and the all references in the Agreement (by
     virtue of Amendment No. 1 thereto) to the words "New Loans" and "New Notes"
     shall mean,  respectively,  only the Legacy Loans and Legacy Notes, and the
     parties  further  agree that,  notwithstanding  the statement in any Legacy
     Note to the effect that such note is a "Note" or "New Note"  referenced  in
     the  Agreement or any amendment  thereto,  such Legacy Note is and shall be
     deemed a Legacy Note (and not a "Note")  under and for all  purposes of the
     Agreement;

<PAGE>

               (c) All references in the Agreement to the term  "Holders"  shall
     include, in addition and not in limitation,  Signal, the registered holders
     from time to time of the Notes,  and the  registered  holders  from time to
     time of the Legacy Notes;

               (d) All references in the Agreement to the term "Loan  Documents"
     shall  include,  in  addition  and  not  in  limitation,  the  Signal  Loan
     Agreement, the Signal Note, the Notes and the Legacy Notes;

               (e)  All  references  in  the  Agreement  to  the  term  "Special
     Majority"  shall include,  in addition and not in limitation,  Signal,  the
     Majority Note Holders and the Majority Legacy Note Holders;

               (f) "Majority Note Holders" shall mean the registered  holders of
     at least a majority in aggregate  principal amount of the Notes outstanding
     at the time of determination;

               (g)  "Majority  Legacy Note  Holders"  shall mean the  registered
     holders of at least a majority in aggregate  principal amount of the Legacy
     Notes outstanding at the time of determination;

               (h) Schedule  3(b) is deleted and  replaced  with  Schedule  3(b)
     attached hereto;

               (i) Signal and the Majority Legacy Note Holders shall be included
     in Section 4 as additional  parties that are permitted to give direction to
     the Agent following the occurrence of an event of default;

               (h) "Event of Default"  shall mean any event of default  referred
     to in  Paragraph  5 of  the  Agreement  and,  unless  the  context  clearly
     indicates  otherwise,  each  use of the  term  "event  of  default"  in the
     Agreement  (including  this  Amendment)  shall mean (i) if  referring to an
     event of default  under the  Agreement,  an Event of Default  and,  (ii) if
     referring to an event of default under any other  agreement or  instrument,
     an Event of Default,  event of default or such other term of similar import
     used in such  agreement or  instrument  to denote an event giving rise to a
     right to accelerate or foreclose with or without notice;

               (i) Signal and the Majority Legacy Note Holders shall be included
     in Section 6 as additional  parties that are permitted to give direction to
     the Agent upon the  occurrence  of any Event of Default other than an Event
     of Default relating to the bankruptcy or insolvency of any Borrower, and as
     additional  parties  that may direct the Agent to  exercise  the rights and
     remedies granted under the Agreement;

               (j) Signal and the Majority  Legacy  Holders shall be included in
     Section 6(c) as additional  parties that are permitted to set off and apply
     for the payment of any or all of the Obligations for the ratable benefit of
     the Holders;

               (k) With respect to Section 8:

                    (i) New "second" and "third"  clauses are hereby  added,  to
          read as follows:

<PAGE>

                              "second,  to  the  ratable payment of accrued  but
                         unpaid interest (including post-petition  interest) and
                         fees constituting  Obligations  pursuant  to the Signal
                         Note and the Legacy Loans;

                              third,  to the ratable payment of unpaid principal
                         of the Signal Note and the Legacy Loans";

                    (ii) clauses "second" through "tenth" are hereby  renumbered
          clause "fourth" through "twelfth", respectively; and

                    (iii) as so  renumbered,  new clauses  "fourth"  and "fifth"
          shall refer solely to  interest,  fees and  principal  pursuant to the
          Notes (and not pursuant to the Legacy Notes); and

               (l) Signal and the Majority legacy Note Holders shall be included
     in Section 9.1 as additional parties are permitted to instruct the Agent to
     take any action to foreclose or otherwise realize on the Collateral; and

          6. Agrees that, as amended hereby, the Agreement is hereby affirmed or
reaffirmed and ratified by all signatories hereto and shall remain in full force
and effect and,  without  limiting the generality of the foregoing,  each of the
Borrowers  hereby  affirms or reaffirms,  ratifies and hereby grants anew to the
Agent,  for the  ratable  benefit  of the Agent and the  Holders,  the  security
interest set forth in the  Agreement  to secure all of the Junior  Indebtedness,
the Legacy Loans, the Signal Loans and any amounts now or hereafter owing by the
Borrowers,  or any of them,  to the  Agent in its  capacity  as Agent  under the
Agreement,  all in accordance  with and subject to the terms of the Agreement as
amended  hereby,  and  each of the  signatories  hereby  affirms  or  reaffirms,
ratifies and hereby renews its agreement to be bound by all terms and conditions
of the  Agreement  (as  amended  hereby),  including,  without  limitation,  the
relative rights, preferences and priorities afforded by the Agreement to each of
them, and each of the Holders  hereby affirms or reaffirms,  ratifies and hereby
authorizes  anew  Cramer,  Rosenthal,  McGlynn,  LLC  as  its  Agent  under  the
Agreement,  for all purposes thereof and entitled to all the rights and benefits
accorded  to the Agent  thereunder.

          THE BORROWERS AND SIGNAL hereby further covenant and agree, until such
time as  Signal  may have  exercised  its  right  under  the  Signal  Management
Agreement or the Signal Loan Agreement to acquire the New York Business  Assets,
to take all necessary or prudent  actions as the Agent may request to ensure the
continued perfection of the security interest granted under the Agreement in and
to all assets of either  Borrower  that may be relocated to Florida or elsewhere
pursuant to the Signal  Transaction  Documents,  including the identification of
all locations  where assets and/or books and records may be kept,  the filing of
additional UCC financing  statements and, to the extent practicable,  separately
identifying  and/or  tracking the assets of the Borrowers  from those of Signal,
and not  commingling  the same,  and  (subject  to its  rights  under the Signal
Management Agreement and Signal Loan Agreement) Signal shall hold and manage the
same in trust for the Agent and the Holders.

          THE  BORROWERS AND THE AGENT hereby  covenant and agree,  upon the due
exercise of Signal's right under the Signal  Management  Agreement or the Signal
Loan Agreement to acquire the New York Business Assets, to take all necessary or

<PAGE>

prudent  actions as Signal may  request to release and record the release of the
security  interest  granted  under the Agreement in and to the New York Business
Assets,  including the delivery of executed UCC termination  statements prepared
by Signal.

          This Amendment  shall become  effective upon the date (the "Effective
Date") that each of the following conditions precedent shall be true:

               (a) Agent shall have received a counterpart  hereof duly executed
     and delivered by each intended party hereto;

               (b)  Agent  shall  have  received  a copy of  each of the  Signal
     Transaction  Documents,  each in form  and  substance  satisfactory  to the
     Agent,  as duly  executed and  delivered  by each of the  intended  parties
     thereto;

               (c) Agent shall have  received a copy of each of the Legacy Notes
     to be outstanding after giving effect to the Legacy Loans to be outstanding
     as of the Effective Date hereof, each as duly executed and delivered to the
     Holders of the Legacy Notes, and

               (d) Agent  shall have  received  a copy of a consent,  waiver and
     extension,  in form and substance  satisfactory to the Agent, duly executed
     and delivered by North Fork Bank, (i) consenting to the Signal  Transaction
     Documents and the transactions  contemplated  thereunder;  (ii) waiving any
     existing default or Event of Default, including any occasioned by the entry
     into this  Amendment or the Signal  Documents and the  consummation  of the
     transactions  contemplated  thereunder,  and (iii)  extending to not sooner
     than June 30,  2000,  the  maturity  date of,  and the  requirement  of any
     principal  payment  under,  the North  Fork Bank  facility  (together  with
     evidence satisfactory to the Agent that all conditions to the effectiveness
     thereof shall have been satisfied; and

         This Amendment  may be executed  in  counterparts,  each of which shall
be deemed an original and all of  which  together  shall  constitute one and the
same instrument.

                  [Remainder of page intentionally left blank]

<PAGE>


          IN WITNESS  WHEREOF,  the parties  hereto have executed or caused this
Agreement to be executed as of the date first written above.


                                          LOGIMETRICS, INC.



                                          By:
                                               _________________________________
                                               Name:  Norman M. Phipps
                                               Title: President and Chief
                                                      Operating Officer


                                          MMTECH, INC.



                                          By:  _________________________
                                               Name:
                                               Title:


                                          CRAMER ROSENTHAL McGLYNN, LLC,
                                                  as Agent



                                          By:
                                             ___________________________________
                                             Name: Sam Beritela
                                             Title: Vice President and Chief
                                                    Financial Officer

<PAGE>


                                          CRAMER ROSENTHAL McGLYNN, INC.,



                                          By:
                                               _________________________________
                                               Name: Sam Beritela
                                               Title: Vice President and Chief
                                                      Financial Officer

                                          520 Madison Avenue
                                          New York, New York 10022
                                          Tel:  (212) 838-3830
                                          Fax:  (212) 644-8291

                                          L.A.D. EQUITY PARTNERS, L.P.

                                          By:  Flint Investments, Inc.
                                               Its General Partner



                                          By:
                                               _________________________________
                                               Name: Arthur J. Pergament
                                               Title: Vice President

                                          520 Madison Avenue
                                          New York, New York 10022
                                          Tel:  (212) 838-3830
                                          Fax:  (212) 644-8291



                                          ______________________________________
                                          Gerald B. Cramer

                                          520 Madison Avenue
                                          New York, New York 10022
                                          Tel:  (212) 838-3830
                                          Fax:  (212) 644-8291

<PAGE>


                                          ___________________________________
                                          Edward J. Rosenthal Profit Sharing
                                          Plan and Trust

                                          520 Madison Avenue
                                          New York, New York 10022
                                          Tel:  (212) 838-3830
                                          Fax:  (212) 644-8291

                                          CRM 1997 ENTERPRISE FUND, LLC

                                          By:  Cramer Rosenthal McGlynn, Inc.,
                                               Its Managing Member



                                          By:
                                               _________________________________
                                               Name: Sam Beritela
                                               Title: Vice President and Chief
                                                      Financial Officer

                                          520 Madison Avenue
                                          New York, New York 10022
                                          Tel:  (212) 838-3830
                                          Fax:  (212) 644-8291

                                          CRM PARTNERS, L.P.

                                          By:  Cramer Rosenthal McGlynn, Inc.,
                                               Its General Partner



                                          By:
                                               _________________________________
                                               Name: Sam Beritela
                                               Title: Vice President and Chief
                                                      Financial Officer

                                          520 Madison Avenue
                                          New York, New York 10022
                                          Tel:  (212) 838-3830
                                          Fax:  (212) 644-8291

                                          CRM RETIREMENT PARTNERS, L.P.

                                          By:  Cramer Rosenthal McGlynn, Inc.,
                                               Its General Partner



                                          By:
                                               _________________________________
                                               Name: Sam Beritela
                                               Title: Vice President and Chief
                                                      Financial Officer

                                          520 Madison Avenue
                                          New York, New York 10022
                                          Tel:  (212) 838-3830
                                          Fax:  (212) 644-8291

                                          CRM MADISON PARTNERS, L.P.

                                          By:  Cramer Rosenthal McGlynn, Inc.,
                                               Its General Partner



                                          By:
                                               _________________________________
                                               Name: Sam Beritela
                                               Title: Vice President and Chief
                                                      Financial Officer

                                          520 Madison Avenue
                                          New York, New York 10022
                                          Tel:  (212) 838-3830
                                          Fax:  (212) 644-8291

<PAGE>

                                          CRM U.S. VALUE FUND, LTD.

                                          By:  Cramer Rosenthal McGlynn, Inc.,
                                               Its General Partner



                                          By:
                                               _________________________________
                                               Name: Sam Beritela
                                               Title: Vice President and Chief
                                                      Financial Officer

                                          520 Madison Avenue
                                          New York, New York 10022
                                          Tel:  (212) 838-3830
                                          Fax:  (212) 644-8291

                                          EURYCLEIA PARTNERS, L.P.

                                          By:  Marchessini & Dernisch, L.L.C.,
                                               Its General Partner


                                          By:
                                               _________________________________
                                               Name: Rona Trokie
                                               Title: Vice President

                                          745 Fifth Avenue, Suite 1400
                                          New York, New York 10151
                                          Tel:  (212) 752-4300
                                          Fax:  (212) 752-4309

                                          A.C. ISRAEL ENTERPRISES, INC.



                                          By:
                                               _________________________________
                                               Name:  Jay Howard
                                               Title:

                                          520 Madison Avenue
                                          New York, New York 10022
                                          Tel:  (212) 838-3830
                                          Fax:  (212) 644-8291

<PAGE>

                                          CRM-EFO PARTNERS, L.P.

                                          By:  CRM-EFO Investments, LLC,
                                               Its General Partner

                                          By:  Cramer Rosenthal McGlynn, Inc.,
                                               Its Managing Member



                                          By:
                                               _________________________________
                                               Name:  Sam Beritela
                                               Title: Vice President and Chief
                                                      Financial Officer

                                          520 Madison Avenue
                                          New York, New York 10022
                                          Tel:  (212) 838-3830
                                          Fax:  (212) 644-8291



                                          ______________________________________
                                          Richard S. Fuld, Jr.

                                          By:  Cramer Rosenthal McGlynn, Inc.,
                                               Attorney-in-Fact



                                          By:
                                               _________________________________
                                               Name:  Sam Beritela
                                               Title: Vice President  and  Chief
                                                      Financial Officer

                                          520 Madison Avenue
                                          New York, New York 10022
                                          Tel:  (212) 838-3830
                                          Fax:  (212) 644-8291

<PAGE>


                                          PAMELA EQUITIES CORP.



                                          By:  _________________________________
                                               Name:
                                               Title:

                                         3 New York Plaza
                                         18th Floor
                                         New York, New York 10004
                                         Tel:  (212) 837-4829
                                         Fax:  (212) 837-4938

                                         WHITEHALL PROPERTIES, LLC



                                         By:  ________________________
                                              Name:
                                              Title: Manager

                                         3 New York Plaza
                                         18th Floor
                                         New York, New York 10004
                                         Tel:  (212) 837-4829
                                         Fax:  (212) 837-4938


                                         KABUKI PARTNERS ADP, GP



                                         By:  ________________________
                                              Name:
                                              Title:  General Partner

                                         3 New York Plaza
                                         18th Floor
                                         New York, New York 10004
                                         Tel:  (212) 837-4829
                                         Fax:  (212) 837-4938

<PAGE>

                                         MBF BROADBAND SYSTEMS, L.P.

                                         By:  MBF Broadband Systems, Inc.,
                                              Its General Partner

                                         By:
                                              __________________________________
                                              Name:  Mark B. Fisher
                                              Title:  President

                                         12 East 49th Street
                                         35th Floor
                                         New York, New York 10017
                                         Telephone:  (212) 339-2861
                                         Facsimile:  (212) 339-2834




                                          ______________________________________
                                          Mark B. Fisher

                                          12 East 49th Street
                                          35th Floor
                                          New York, New York 10017
                                          Telephone:  (212) 339-2861
                                          Facsimile:  (212) 339-2834

                                          McGLYNN FAMILY PARTNERSHIP



                                          By:
                                               _________________________________
                                               Name:  Ronald H. McGlynn
                                               Title:  General Partner

                                          520 Madison Avenue
                                          New York, New York 10022
                                          Tel:  (212) 838-3830
                                          Fax:  (212) 644-8291

<PAGE>


                                          ______________________________________
                                          Fred M. Filoon

                                          520 Madison Avenue
                                          New York, New York 10022
                                          Tel:  (212) 838-3830
                                          Fax:  (212) 644-8291




                                          ______________________________________
                                          Eugene A. Trainor, III

                                          520 Madison Avenue
                                          New York, New York 10022
                                          Tel:  (212) 838-3830
                                          Fax:  (212) 644-8291

                                          CERBERUS PARTNERS, L.P.

                                          By:  Cerberus Associates, L.L.C.,
                                               Its General Partner

                                          By:
                                               _________________________________
                                               Name:  Stephen Feinberg
                                               Title:  Managing Member

                                          450 Park Avenue
                                          28th Floor
                                          New York, New York 10022
                                          Telephone:  (212) 891-2100
                                          Facsimile:  (212) 421-2947

<PAGE>


                                          ______________________________________
                                          Steven Dinetz

                                          1034 Skyland Drive
                                          Zephyr Cove, Nevada 89448
                                          Tel:  (702) 588-0343
                                          Fax:  (702) 588-1433

                                          CRM 1998 ENTERPRISE FUND, LLC

                                          By:  Cramer Rosenthal McGlynn, Inc.,
                                               Its Managing Member



                                          By:
                                               _________________________________
                                               Name: Sam Beritela
                                               Title: Vice President and Chief
                                                      Financial Officer

                                          520 Madison Avenue
                                          New York, New York 10022
                                          Tel:  (212) 838-3830
                                          Fax:  (212) 644-8291




                                          ______________________________________
                                          Charles S. Brand

                                          611 Industrial Way West
                                          Eatontown, New Jersey 07724
                                          Tel:  (732) 935-0853
                                          Fax:(732) 935-7151

<PAGE>


                                          ______________________________________
                                          Gregory Manocherian

                                          135 Central Park West, Tower Southeast
                                          New York, New York 10023
                                          Tel:  (212) 799-3500
                                          Fax:  (212) 873-2877




                                          SIGNAL TECHNOLOGY CORPORATION



                                          By:___________________________________
                                                 [Authorized Signatory]



<PAGE>

<TABLE>
<CAPTION>

                                   Schedule A


---------------------------------------------- ------------------------------------ ------------------------------
<S>                                                   <C>                                   <C>
         Legacy Note Holder                            Existing Legacy Notes                New Legacy Notes

---------------------------------------------- ------------------------------------ ------------------------------
Pamela Equities Corp.
---------------------------------------------- ------------------------------------ ------------------------------
A.C. Israel Enterprises, Inc.
---------------------------------------------- ------------------------------------ ------------------------------
Gerald B. Cramer
---------------------------------------------- ------------------------------------ ------------------------------
CRM 1997 Enterprise Fund, LLC
---------------------------------------------- ------------------------------------ ------------------------------
Whitehall Properties, LLC
---------------------------------------------- ------------------------------------ ------------------------------
CRM Partners, L.P.
---------------------------------------------- ------------------------------------ ------------------------------
CRM Retirement Partners, L.P.
---------------------------------------------- ------------------------------------ ------------------------------
CRM Madison Partners, L.P.
---------------------------------------------- ------------------------------------ ------------------------------
L.A.D. Equity Partners, L.P.
---------------------------------------------- ------------------------------------ ------------------------------
CRM-EFO Partners, L.P.
---------------------------------------------- ------------------------------------ ------------------------------
Gregory Manocherian
---------------------------------------------- ------------------------------------ ------------------------------
CRM U.S. Value Fund, Ltd.
---------------------------------------------- ------------------------------------ ------------------------------
Edward J. Rosenthal, Keogh
---------------------------------------------- ------------------------------------ ------------------------------
Fred M. Filoon
---------------------------------------------- ------------------------------------ ------------------------------
McGlynn Family Partnership, L.P.
---------------------------------------------- ------------------------------------ ------------------------------
Eugene A. Trainor, III
---------------------------------------------- ------------------------------------ ------------------------------
Cereberus Partners, L.P.
---------------------------------------------- ------------------------------------ ------------------------------
TOTAL                                                       $320,000                          $680,000
---------------------------------------------- ------------------------------------ ------------------------------
</TABLE>


<PAGE>


                                    EXHIBIT A



                                     FORM OF
                         SUPPLEMENTAL NEGOTIABLE SECURED
                       SENIOR SUBORDINATED PROMISSORY NOTE



$_____________
                                                           Final Maturity Date:
                                                                  ________, 2000


FOR VALUE RECEIVED, LogiMetrics, Inc., a Delaware corporation, and mmTech, Inc.,
a New Jersey  corporation  (collectively,  the  "Makers"),  hereby  jointly  and
severally  promise to pay to the order of  _____________,  or its successors and
assigns  (the  "Holder"),  at  ______________  or at such other  location as the
Holder  may  designate  from time to time,  the sum of  ________________________
Dollars  ($___________),  or such lesser  amount as may be  advanced  hereunder,
together with interest  thereon at the rate of 13% per annum, in lawful money of
the United States of America on or before June 2, 2000, or on demand at any time
upon or during the continuance of an Event of Default as defined in the Security
Agreement (as defined below), with or without demand as provided in the Security
Agreement.  The  obligations  of the Makers are joint and several and the Holder
may proceed to collect the full amount owed  hereunder from either Maker whether
or not proceeding against the other.

          If the Holder  fails to pay any amount  hereunder  when due,  interest
shall  thereafter  accrue  on such  overdue  amount at the rate of 16% per annum
until paid in full.  Interest  hereunder  shall be  calculated on the basis of a
360-day year for the actual number of days elapsed.

          The  Makers  may  prepay  this Note at any time,  in whole or in part,
without  premium or penalty.  The Makers  shall  prepay this Note in full within
five (5) Business Days after the  consummation of (i) any public or private sale
by either Maker of its debt or equity securities or securities  convertible into
or exchangeable  for its debt or equity  securities,  (ii) any permanent loan or
other credit  facility  obtained by either Maker from a bank or other  financial
institution,  or (iii) any sale by either Maker of all or  substantially  all of
its assets to a third party which results, in each such case, in net proceeds to
the Makers  (after all related  fees and  expenses)  of at least  Three  Million
Dollars ($3,000,000).  As used herein,  "Business Day" means a day, other than a
Saturday or Sunday,  on which commercial banks in New York City are open for the
general transaction of business.

          The Makers shall pay to the Holder the reasonable  attorneys' fees and
disbursements and all other  out-of-pocket costs incurred by the Holder in order
to collect amounts due and owing under this Note. All payments received shall be
applied,  first, to the costs of collection,  second,  to unpaid  interest,  and
third, to principal.

<PAGE>

          No delay or failure on the part of the Holder in exercising any power,
right or remedy hereunder shall operate as a waiver of any such power,  right or
remedy;  nor shall any single or partial exercise of any power,  right or remedy
preclude any other or further  exercise of such power,  right or remedy,  or the
exercise of any other power,  right or remedy, and no waiver whatsoever shall be
valid  unless in  writing,  signed by the  Holder,  and then only to the  extent
expressly set forth therein.  No remedy is exclusive of any other remedy and all
remedies shall be cumulative to the maximum extent  permitted by applicable law.
Each Maker hereby waives presentment,  demand for payment,  diligence, notice of
dishonor  and all other  notices  or demands in  connection  with the  delivery,
acceptance, performance, default or endorsement of this Note.

          This Note is one of the Legacy Notes  referred to in Amendment  No. 2,
dated on or about the date hereof,  to the Second Amended and Restated  Security
Agreement, Intercreditor Agreement, Waiver and Consent, dated on or about August
31, 1999 and as further amended by Amendment No. 1 thereto, dated as of December
2,  1999,  among the  Makers,  Cramer  Rosenthal  McGlynn,  LLC,  as Agent  (the
"Agent"),  and the other parties  thereto,  (as amended by such Amendment No. 2,
the "Security  Agreement")  and is secured by the  Collateral (as defined in the
Security  Agreement).  The Security  Agreement grants the Agent on behalf of the
Holder  and the  other  parties  thereto  certain  rights  with  respect  to the
Collateral upon certain  defaults  specified  therein and sets forth the related
priorities  of the  Holder and the other  parties  thereto  with  regard to such
Collateral.

          This Note shall be  binding  upon each  Maker and its  successors  and
assigns.  This Note shall be governed by, and construed in accordance  with, the
internal  laws of the  State of New York  pursuant  to  Section  15-1402  of the
General  Obligations Law of such state.  Each Maker  irrevocably  submits to the
exclusive  jurisdiction  of the  courts of the State of New York and the  United
States  District Court for the Southern  District of New York for the purpose of
any suit,  action,  proceeding  or  judgment  relating to or arising out of this
Note.  Service of process in connection with any such suit, action or proceeding
may be served on the Makers  anywhere in the world by any method  authorized  by
law. Each Maker  irrevocably  consents to the  jurisdiction of any such court in
any such suit,  action or  proceeding  and to the laying of venue in such court.
Each Maker  irrevocably  waives any objection to the laying of venue of any such
suit,  action or proceeding  brought in such courts and  irrevocably  waives any
claim that any such  suit,  action or  proceeding  brought in any such court has
been brought in an inconvenient forum.

          No modification, alteration, waiver or change of any of the provisions
hereof  shall be  effective  unless in writing  and signed by each Maker and the
Holder and, then, only to the extent set forth in such writing.

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<PAGE>

ATTEST:                                     LOGIMETRICS, INC.



_____________________                       ____________________________________
Name:                                       By: Norman M. Phipps
                                            Title: President


ATTEST:                                     MMTECH, INC.



_____________________                       _____________________________
Name:                                       By: Norman M. Phipps
                                            Title: Assistant Secretary

Dated: _____, 2000