EXHIBIT 10.6

                                LogiMetrics, Inc.
                                50 Orville Drive
                             Bohemia, New York 11716



                                February 16, 2000



North Fork Bank
275 Broad Hollow Road
Melville, New York 11747

          Attention: Joseph Walsh Senior Vice President

Dear Joe:

          Reference  is hereby made to the (i)  $1,930,000  Reduced and Extended
Revolving Credit Note, dated as of September 1, 1999 (the  "Revolver"),  made by
LogiMetrics,  Inc. (the "Company") and mmTech,  Inc. in favor of North Fork Bank
(the "Bank"),  (ii) Modified General Security  Agreement,  dated April 30, 1998,
made by the  Company in favor of the Bank,  (iii)  General  Security  Agreement,
dated April 30, 1998,  made by mmTech,  Inc. in favor of the Bank,  (iv) Blocked
Account  Agreement,  dated April 25, 1997, between the Company and the Bank, and
(v) Recognition and Limited Forbearance Agreement, dated as of September 1, 1999
made by and among the  Company,  mmTech,  Inc. and the Bank  (collectively,  the
"Bank Documents").

          As we have previously discussed,  the Company has been negotiating the
terms and  conditions  of a proposed  transaction  pursuant to which the Company
intends to enter into a letter of intent (the  "Letter of  Intent")  with Signal
Technology  Corporation  ("Signal")  pursuant to which Signal intends to acquire
the  Company  in a  tax-free  merger  (the  "Merger").  In  connection  with the
execution  of the Letter of Intent,  Signal has agreed to loan to the Company up
to  $2,000,000  pursuant to the terms of a proposed  loan  agreement  (the "Loan
Agreement") and a Negotiable  Secured Senior  Subordinated  Promissory Note (the
"Note").  Under the terms of the Loan Agreement,  certain existing  creditors of
the  Company  would also  advance up to  $1,000,000  to the  Company  and mmTech
($610,000  of which has been  advanced  since  December  2, 1999)  (the  "Legacy
Loans").  The obligations of the Company and mmTech under the Loan Agreement and
the Legacy Loans would be secured by a security interest in all of the assets of
the Company and the  subsidiaries  that would rank junior to the Bank's security
interests  and senior to the other  indebtedness  of the Company and mmTech.  In
addition,  the Company proposes to enter into a Management Agreement with Signal
(the "Management Agreement"), pursuant to which Signal would agree to manage the
Company's  current  business  located  in  Bohemia,  New  York  (the  "New  York
Business").  Pursuant to the Management Agreement,  Signal would relocate all of
the assets of the New York  Business,  (excluding  real estate and fixtures) and
consisting entirely of those assets listed on Exhibit A (the "New York Assets"),
to Signal's existing facility in Florida. Pursuant to the Loan Agreement and the
Management  Agreement,  Signal also would have the right to acquire the New York
Business on the terms and  conditions  set forth  therein.  Under the Management
Agreement,  Signal also would pay the Company's ongoing debt service obligations
to the Bank during the period that Signal was operating  the New York  Business.
The  transactions  described  above are  hereinafter  referred to as the "Signal
Transactions". In order to consummate the Signal Transactions, the Bank would be
required,  among other things,  to release its security interest in the New York
Assets upon the written  notification by Signal that it is taking legal title to
those assets.

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          By executing this letter in the space provided below,  the Bank hereby
irrevocably  consents  to the  consummation  of the Merger and the other  Signal
Transactions,  including,  without  limitation,  the  grant  of any  subordinate
security  interest  securing the Legacy Loans and the Note and the relocation of
the assets of the New York  Business to Signal's  facility in Florida.  Further,
the  Bank  hereby  (i)  subordinates   its  security   interest  in  the  assets
constituting  the New York Assets to the  security  interest of Signal (ii) upon
written  notification  by Signal  that it is taking  legal  title to the  assets
constituting the New York Assets,  shall promptly release without any additional
consideration  its  security  interest in those  assets upon  confirmation  that
Signal has advanced the full $2,000,000  under the Loan Agreement,  (iii) agrees
to execute such documents or  instruments  as Signal may  reasonably  require to
effect the release of such  security  interest,  (iv) agrees to the  priority of
security  interests in the New York Assets  described above, and (v) irrevocably
waives any  defaults  under the Bank  Documents,  whether  existing  on the date
hereof or arising in connection with the Signal Transactions.

          Finally,  the Bank would agree to modify and extend the maturity  date
of the Revolver  from  December 31, 1999 to June 30,  2000,  all such  consents,
agreements,  waivers  and  modifications  subject  to  the  satisfaction  of the
conditions set forth below:

               (i)  the Company must have  received no less than  $1,660,000  in
                    additional   subordinated   financing   (including   amounts
                    advanced by the Company's  existing investors since December
                    2,  1999);

               (ii) the  modification and extension will be evidenced in part by
                    the execution of a further modified and extended note;

               (iii)the amount  available under the Revolver shall be reduced to
                    $1,785,576 and no additional advances will be made; and

               (iv) all past due interest ($72,793.41 a/o 2/15/00), a waiver fee
                    in the amount of  $10,000,  and Bank  attorney  fees (not to
                    exceed $10,000) shall be paid in full.

               (v)  the Company agrees to pay a $10,000 exit fee at maturity;

               (vi) the Company  extends the expiration  date of the warrants to
                    6/30/00  and prior to the  modification  and  extension  the
                    Company  shall  provide  the Bank with an opinion of counsel
                    confirming the validity an enforceability of said warrants.

All other terms and  conditions  of the Revolver  shall remain the same,  except
that  paragraph  (h) as  set  forth  in the  Affirmative  Covenant  section  and
paragraphs  (a), (b) and (c) as set forth in the  Financial  Statements  section
relating   to  certain   financial   covenants   and   reporting   requirements,
respectively, required of the Company by the Bank are hereby deleted.

          This consent shall be governed by, and  construed in accordance  with,
the laws of the State of New York,  without regard to principles of conflicts of
law. It may be executed in one or more  counterparts,  each of which shall be an
original, but all of which together shall constitute a single agreement.

                                           Very truly yours,

                                           LOGIMETRICS, INC.


                                           By:  /s/Norman M. Phipps
                                                ________________________________
                                                Name:  Norman M. Phipps
                                                Title: President and Chief
                                                       Operating Officer

CONSENTED AND AGREED TO:

NORTH FORK BANK


By:  /s/Joseph Walsh
     ____________________________
     Name:  Joseph Walsh
     Title: Senior Vice President

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                                    EXHIBIT A


Logimetrics, Inc.
New York Business


Accounts receivable, Net
Inventory
Prepaid and other current assets
Property, plant and equipment
Security deposits
         Total Assets


The New York Assets as defined herein do not include or relate to the conduct of
the business of mmTech, Inc.