EXHIBIT 4.13

THESE  SECURITIES HAVE NOT BEEN REGISTERED  UNDER THE SECURITIES ACT OF 1933, AS
AMENDED,  OR THE SECURITIES  LAWS OF ANY STATE AND CANNOT BE SOLD OR TRANSFERRED
UNLESS AND UNTIL THEY ARE SO REGISTERED OR UNLESS AN EXEMPTION UNDER SUCH ACT OR
LAWS IS AVAILABLE.


                                LOGIMETRICS, INC.

                    Common Stock Purchase Warrant - Series J


          LOGIMETRICS,  INC. (the  "Company"),  a Delaware  corporation,  hereby
certifies  that,  for value  received,  ______________________,  or assigns,  is
entitled,  subject to the terms set forth  below,  to purchase  from the Company
____________  __________  (___________) fully paid and non-assessable  shares of
Common Stock, par value $.01 per share, of the Company (the "Common Stock"),  at
a purchase price of fifty-five cents ($0.55) per share (the "Purchase Price") at
any time prior to July 1, 1999.  The number  and  character  of such  shares are
subject to adjustment as provided below, and the term "Common Stock" shall mean,
unless the context otherwise requires, the stock or other securities or property
at the time deliverable upon the exercise of this Warrant.

          1. EXERCISE OF WARRANT.  The purchase rights evidenced by this Warrant
shall be exercised by the holder hereof  ("Holder")  surrendering  this Warrant,
with the form of subscription at the end hereof duly executed by such Holder, to
the Company at its office in Bohemia,  New York (or such other  office as may be
designated by the Company from time to time), accompanied by payment (in cash or
by certified or official bank check).

          2. DELIVERY OF STOCK CERTIFICATES ON EXERCISE.  As soon as practicable
after the exercise of this Warrant and payment of the Purchase Price, and in any
event within five (5) business  days  thereafter,  the Company,  at its expense,
will  cause to be issued in the name of and  delivered  to the  Holder  hereof a
certificate  or  certificates  for the number of fully  paid and  non-assessable
shares of Common  Stock or other  securities  or  property  to which such Holder
shall be entitled  upon such  exercise,  plus, in lieu of any  fractional  share
interest to which such Holder would  otherwise  be entitled,  cash equal to such
fraction multiplied by the then current market value of one full share of Common
Stock or other securities to which such Holder shall be so entitled.

          3.   ADJUSTMENT  FOR  DIVIDENDS  IN  OTHER  STOCK,   PROPERTY,   ETC.;
RECLASSIFICATIONS,  ETC. In case at any time or from time to time after the date
of  issuance of this  Warrant  (the  "Issuance  Date") the holders of the Common
Stock  of the  Company  of any  class  (or any  other  shares  of stock or other
securities at the time  receivable upon the exercise of this Warrant) shall have
received,  or, on or after  the  record  date  fixed  for the  determination  of
eligible stockholders, shall have become entitled to receive:

               (a)  other or  additional  stock or other  securities or property
                    (other than cash) by way of dividend;

               (b)  any cash paid or payable  out of capital or paid-in  surplus
                    or surplus  created as a result of a revaluation of property
                    by way of dividend; or

               (c)  other or additional  (or less) stock or other  securities or
                    property  (including cash) by way of stock-split,  spin-off,
                    split-off, split-up, reclassification, combination of shares
                    or similar corporate rearrangement;

<PAGE>


then in each  case the  Holder  of this  Warrant,  upon the  exercise  hereof as
provided in Paragraph 1 hereof,  shall be entitled to receive, in lieu of, or in
addition  to, as the case may be, the  shares  theretofore  receivable  upon the
exercise of this  Warrant,  the amount of stock or other  securities or property
(including  cash in the cases  referred to in clauses  (b) and (c) above)  which
such Holder would hold on the date of such exercise if, on the Issuance Date, he
had been the  holder of record  of the  number of shares of Common  Stock of the
Company  called for on the face of this Warrant and had  thereafter,  during the
period  from the  Issuance  Date to and  including  the  date of such  exercise,
retained  such shares  and/or all other or  additional  (or less) stock or other
securities or property  (including  cash in the cases referred to in clauses (b)
and (c) above) receivable by the Holder as aforesaid during such period,  giving
effect to all adjustments called for during such period by Paragraph 4 hereof.

          4. ADJUSTMENT FOR REORGANIZATION,  CONSOLIDATION, MERGER, ETC. In case
of any  reorganization  of the  Company (or any other  corporation  the stock or
other  securities of which are at the time  deliverable  on the exercise of this
Warrant) after the date hereof, or in case, after such date, the Company (or any
such other corporation) shall consolidate with or merge into another corporation
or convey all or substantially all its assets to another  corporation,  then and
in each  such case the  Holder  of this  Warrant,  upon the  exercise  hereof as
provided  in  Paragraph 1  hereof,  at any time after the  consummation  of such
reorganization,  consolidation,  merger  or  conveyance,  shall be  entitled  to
receive the stock or other  securities  or  property to which such Holder  would
have been entitled  upon such  consummation  if such Holder had  exercised  this
Warrant  immediately  prior  thereto,  all  subject  to further  adjustments  as
provided in  Paragraph 3  hereof;  in each such case,  the terms of this Warrant
shall be  applicable  to the  shares of stock or other  securities  or  property
receivable upon the exercise of this Warrant after such consummation.

          5. NO DILUTION OR  IMPAIRMENT.  The Company  will not, by amendment of
its charter or through reorganization,  consolidation, merger, dissolution, sale
of assets or any other voluntary  action,  avoid or seek to avoid the observance
or  performance  of any of the terms of this  Warrant,  but will at all times in
good faith assist in the carrying out of all such terms and in the taking of all
such action as may be necessary or appropriate in order to protect the rights of
the Holder hereof against  dilution or other  impairment.  Without  limiting the
generality of the foregoing,  the Company will not increase the par value of any
shares of stock  receivable  upon the exercise of this Warrant  above the amount
payable therefor upon such exercise,  and at all times will take all such action
as may be  necessary  or  appropriate  in order that the Company may validly and
legally  issue  fully paid and  non-assessable  stock upon the  exercise of this
Warrant.

          6.  ACCOUNTANTS'  CERTIFICATE  AS TO  ADJUSTMENTS.  In each case of an
adjustment in the number of shares of Common Stock or other stock, securities or
property  receivable  on the  exercise  of this  Warrant,  at the request of the
Holder  of  this  Warrant  the  Company  at its  expense  shall  promptly  cause
independent public accountants of recognized standing,  selected by the Company,
to compute  such  adjustment  in  accordance  with the terms of this Warrant and
prepare a certificate  setting forth such  adjustment  and showing in detail the
facts upon which such adjustment is based.

          7. NOTICES OF RECORD DATE, ETC. In case:

               (a)  the Company shall take a record of the Holders of its Common
                    Stock (or other stock or securities at the time  deliverable
                    upon  the  exercise  of this  Warrant)  for the  purpose  of
                    entitling or enabling  them to receive any  dividend  (other
                    than a cash or stock  dividend  at the same rate as the rate
                    of the last  cash or  stock  dividend  theretofore  paid) or
                    other  distribution,  or to exercise  any  preemptive  right
                    pursuant to the Company's  charter,  or to receive any right

<PAGE>

                    to  subscribe  for or  purchase  any  shares of stock of any
                    class or any  other  securities,  or to  receive  any  other
                    right; or

               (b)  of  any  capital   reorganization   of  the   Company,   any
                    reclassification  of the capital  stock of the Company,  any
                    consolidation  or merger of the Company with or into another
                    corporation,  or any conveyance of all or substantially  all
                    of the assets of the Company to another corporation; or

               (c)  of the voluntary or involuntary dissolution,  liquidation or
                    winding up of the Company;

then,  and in each such case, the Company will mail or cause to be mailed to the
Holder of this Warrant a notice specifying,  as the case may be, (i) the date on
which a record is to be taken for the purpose of such dividend,  distribution or
right,  and stating the amount and character of such dividend,  distribution  or
right,  or  (ii)  the  date  on  which  such  reorganization,  reclassification,
consolidation,  merger, conveyance, dissolution, liquidation or winding up is to
take  place,  and the times,  if any is to be fixed,  as of which the holders of
record  of  Common  Stock  (or  such  other  stock  or  securities  at the  time
deliverable  upon the  exercise of this  Warrant)  shall be entitled to exchange
their  shares of Common  Stock of any class (or such other stock or  securities)
for   reclassification,    consolidation,   merger,   conveyance,   dissolution,
liquidation  or winding up or (iii) the  amount  and  character  of the stock or
other  securities  proposed to be issued or granted,  the date of such  proposed
issuance  or grant and the  persons  or class of  persons  to whom such stock or
other  securities  are to be offered,  issued or granted.  Such notice  shall be
mailed at least thirty (30) days prior to the date therein specified.

          8. RESERVATION OF STOCK, ETC.,  ISSUABLE ON EXERCISE OF WARRANTS.  The
Company will at all times  reserve and keep  available,  solely for issuance and
delivery  upon the exercise of this  Warrant and other  similar  Warrants,  such
shares of Common Stock and other stock,  securities and property as from time to
time shall be issuable  upon the exercise of this Warrant and all other  similar
Warrants at the time outstanding.

          9.  REPLACEMENT  OF  WARRANT.  Upon  receipt  of  evidence  reasonably
satisfactory  to the Company of the loss,  theft,  destruction  or mutilation of
this Warrant and (in the case of loss, theft or destruction) upon delivery of an
indemnity agreement in an amount reasonably  satisfactory to it, or (in the case
of mutilation) upon surrender and cancellation  thereof, the Company will issue,
in lieu thereof, a new Warrant of like tenor.

          10. REMEDIES.  The Company  stipulates that the remedies at law of the
Holder  of this  Warrant  in the  event of any  default  by the  Company  in its
performance  of or compliance  with any of the terms of this Warrant are not and
will not be adequate, and that the same may be specifically enforced.

          11.  NEGOTIABILITY,  ETC.  This  Warrant is issued upon the  following
terms, to all of which each taker or owner hereof consents and agrees:

               (a)  Title to this warrant may be transferred by endorsement  (by
                    the Holder  hereof  executing  the form of assignment at the
                    end hereof including  guaranty of signature) and delivery in
                    the same  manner as in the case of a  negotiable  instrument
                    transferable by endorsement and delivery.

               (b)  Any person in possession of this Warrant  properly  endorsed
                    is authorized to represent  himself as absolute owner hereof
                    and is granted  power to transfer  absolute  title hereto by
                    endorsement  and  delivery  hereof to a bona fide  purchaser

<PAGE>

                    hereof  for  value;  each  prior  taker or owner  waives and
                    renounces  all of his  equities or rights in this Warrant in
                    favor of every such bona fide purchaser, and every such bona
                    fide purchaser  shall acquire title hereto and to all rights
                    represented hereby.

               (c)  Until  this  Warrant  is  transferred  on the  books  of the
                    Company, the Company may treat the registered Holder of this
                    Warrant  as the  absolute  owner  hereof  for  all  purposes
                    without being affected by any notice to the contrary.

          12.  SUBDIVISION OF RIGHTS.  This Warrant (as well as any new warrants
issued pursuant to the provisions of this paragraph) is  exchangeable,  upon the
surrender  hereof by the Holder hereof,  at the principal  office of the Company
for any  number  of new  warrants  of like  tenor and date  representing  in the
aggregate the right to subscribe for and purchase the number of shares of Common
Stock of the Company which may be subscribed for and purchased hereunder.

          13. MAILING OF NOTICES, ETC. All notices,  requests,  claims, demands,
waivers  and other  communications  hereunder  shall be in writing  and shall be
deemed to have  been duly  given  when  delivered  by hand,  when  delivered  by
courier,  three days after being deposited in the mail  (registered or certified
mail, postage prepaid, return receipt requested),  or when received by facsimile
transmission upon receipt of a confirmed transmission report, as follows:

If to the Company:                  50 Orville Drive
                                    Bohemia, New York 11716
                                    Tel:  (516) 784-4110
                                    Fax:  (516) 784-4132
                                    Attention:  Chief Executive Officer

and if to the Holder of this Warrant to the address  furnished to the Company in
writing by the last Holder of this  Warrant who shall have  furnished an address
to the Company in writing.  Either the Company or the Holder of this Warrant, by
notice given to the other parties hereto in accordance with this Section 15, may
change the  address or  facsimile  transmission  number to which such  notice or
other communications are to be sent to such party.

          14.  HEADINGS,  ETC.  The headings in this Warrant are for purposes of
reference only, and shall not limit or otherwise affect the meaning hereof.

          15. CHANGE,  WAIVER, ETC. Neither this Warrant nor any term hereof may
be changed, waived, discharged or terminated orally but only by an instrument in
writing  signed by the party against which  enforcement  of the change,  waiver,
discharge or termination is sought.

<PAGE>

          16.GOVERNING  LAW.  This Warrant  shall be  construed  and enforced in
accordance with the laws of the State of New York.

                                          LOGIMETRICS, INC.


                                           By: _________________________________



Dated:  October 9, 1998

Attest:


______________________________

<PAGE>


                  [To be signed only upon exercise of Warrant]


To LOGIMETRICS, INC.:

          The  undersigned,  the Holder of the within  Series J Warrant,  hereby
irrevocably  elects to exercise the purchase  right  represented by such Warrant
for,  and to purchase  thereunder,  _________________  shares of Common Stock of
LOGIMETRICS,  INC. and herewith makes payment of $_______ therefor, and requests
that the certificates for such shares be issued in the name of, and be delivered
to, ________________, whose addres is ______________________.


Dated:



_____________________________



________________________________________________________________________________
                              (Signature must conform in all respects to name of
                               Holder as specified on the face of the Warrant)

                               Address:


________________________________________________________________________________

<PAGE>


                  [To be signed only upon transfer of Warrant]


          FOR  VALUE  RECEIVED,   the  undersigned  hereby  sells,  assigns  and
transfers  unto  _______________________  the right  represented  by the  within
Series J Warrant to purchase the ________________  shares of the Common Stock of
LOGIMETRICS,  INC. to which the within  Series J Warrant  relates,  and appoints
________________________  attorney  to  transfer  said  right  on the  books  of
LOGIMETRICS, INC. with full power of substitution in the premises.

Dated:



________________________________



________________________________________________________________________________
                           (Signature  must  conform in all  respects to name of
                            Holder as specified on the face of the Warrant)

                            Address:


________________________________________________________________________________
________________________________________________________________________________

In the presence of



______________________________

<PAGE>

_________

March 10, 2000

_____________
_____________
_____________

          Attention:

          Re.: Common Stock Purchase Warrant - Series J

Dear Holder:

Reference  is hereby made to the Common Stock  Purchase  Warrant - Series J (the
"Series J Warrant")  issued by  LogiMetrics,  Inc.  (the "Company") to you.  The
Company  hereby  agrees  that  the  expiry date of July 1, 1999 set forth in the
first  paragraph  of the Series J Warrant is hereby  extended to June 30, 2000.
All  other terms,  conditions and provisions of the Series J Warrant  remain the
same.

Very truly yours,


_________________________________
Norman M. Phipps
President and
Chief Operating Officer