FOURTH AMENDED AND RESTATED LINE OF CREDIT NOTE

$15,000,000                                               As of February 1, 1999

     FOR VALUE RECEIVED, BLONDER TONGUE LABORATORIES, INC., a Delaware
corporation (the "Borrower"), hereby promises to pay to the order of FIRST UNION
NATIONAL BANK (the "Bank") on the Termination Date the principal amount of
FIFTEEN MILLION DOLLARS (15,000,000) or, if less, the aggregate outstanding
principal under the Line of Credit extended under the Fourth Amended and
Restated Loan Agreement dated the date hereof by and between the Borrower and
the Bank as may be amended, modified or restated from time to time (the "Loan
Agreement"). Terms capitalized but not defined herein shall have the meanings
given to them respectively in the Loan Agreement. Reference is made to the Loan
Agreement for a statement of the terms and conditions under which the loans
evidenced hereby have been made, secured, and may be prepaid or accelerated.
This Note amends and restates and replaces (but does not discharge) the
obligations of the Borrower under the Third Amended and Restated Line of Credit
Note dated October 29, 1997, as such note has been amended, modified and/or
extended.

     Until maturity (whether by acceleration or otherwise) interest shall accrue
on the outstanding principal balance hereof at the rate set forth in the Loan
Agreement. Interest shall be calculated on the basis of a 360-day year, counting
the actual number of days elapsed. Subsequent to maturity or the occurrence of
any Event of Default, and continuing after entry of any judgment against the
Borrower with respect to the obligations evidenced by this Note, interest shall
accrue at an annual rate which shall be two percent (2%) above the rate of
interest otherwise payable hereunder. Accrued interest shall be payable monthly
on the first day of each month commencing with the month immediately following
date hereof and if not paid when due, shall be added to the principal.

     All amounts payable by the Borrower to the Bank hereunder shall be paid
directly to the Bank at 370 Scotch Road, West Trenton, New Jersey 08628 (or at
such other address of which the Bank shall give notice to the Borrower in
accordance with the Loan Agreement) in immediately available funds.

     The Borrower hereby waives the requirements of demand, presentment,
protest, notice of protest and dishonor and all other demands or notices of any
kind in connection with the delivery, acceptance, performance, default, dishonor
or enforcement of this Note.

     The construction, interpretation and enforcement of this Note shall be
governed by the internal law of the State of New Jersey.

     IN WITNESS WHEREOF, and intending to be legally bound hereby, the Borrower
has caused this Note to be executed by its duly authorized officer as of the day
and year first above written.

                                       BLONDER TONGUE LABORATORIES, INC.

                                       By: /s/ James A. Luksch
                                           ----------------------------
                                           James A. Luksch
                                           President