<PAGE>

                                     [LOGO]
                                  PROGRESS BANK

 June 29, 1999

 AM Communications, Inc.
 100 Commerce Drive
 Quakertown, PA 18951-2237

 Attention: Keith D. Schneck
            President


Dear Keith:

I am pleased to inform you that Progress Bank (hereinafter referred to as
"Bank") has approved the following secured line of credit to AM Communications,
Inc. (hereinafter referred to as "Borrower") under the terms and subject to the
conditions set forth below:

 1.      AMOUNT: $750,000

 2.      BORROWER: AM Communications, Inc.

 3.      USE OF PROCEEDS: The advances under the line of credit shall be used
         primarily for working capital and short-term borrowings.

 4.      TERMS: The line of credit will be available to the Borrower until July
         31, 2000, at which time continuation of the line will be considered by
         the Bank on the basis of the Borrower's financial statements for the
         year ended March 31, 2000, and other information available to Bank, or
         which the Bank may reasonably request.

 5.      INTEREST RATE: Wall Street Journal's Prime Rate plus 2.0% floating (an
         increase from the current pricing of WSJ Prime + 1.75%). The Wall
         Street Journal's Prime Rate is a reference rate which floats and is
         stated from time to time by the Bank and is used for the Bank as a
         reference rate with respect to different interest rates charged to
         borrowers. The rate of interest payable shall change simultaneously and
         automatically upon the Bank's designation of any change in such
         reference rate. The Bank's determination and

                                  Exhibits 10-g



<PAGE>


 AM Communications, Inc.                      2                        06/29/99

         designation from time to time of the reference rate shall not in any
         way preclude the Bank from making loans to other borrowers at a rate
         which is higher or lower or different from the reference rate.

 6.      COMMITMENT FEE: The Borrower will pay a non-refundable fee equal to
         .50% ($3,750.00) of the loan amount to the Bank at the time of
         acceptance of the commitment evidenced by the signing of this letter.
         The commitment fee is paid as consideration to the Bank for the
         issuance of this commitment whether or not the transaction contemplated
         herein is closed.

 7.      BORROWING BASE: All advances made under the line of credit will be
         limited to 80% of qualified accounts receivables up to 90 days from
         invoice as defined in the Bank's Secured Lending Operation Procedures
         (see Attachment I).

 8.      CERTIFICATION: The Bank shall require the submission of certifications
         of accounts receivable on a monthly basis. Each certification shall be
         delivered to the Bank no later than ten (10) days after the close of
         each month. Such certification shall be signed by the chief financial
         officer indicating to the best of his knowledge that the certification
         is valid, accurate, and prepared in accordance with Bank requirements.

 9.      COLLATERAL: As security for the line of credit, the Bank will require
         a first priority security interest perfected under the Uniform
         Commercial Code in all of the Borrower's corporate assets, including
         present and future accounts, chattel paper, contracts, documents,
         present and future equipment (including, but not limited to fixtures,
         office equipment, furniture and motor vehicles), and accessions,
         general intangibles, instruments, inventory, and any products and
         proceeds of the foregoing. The Bank will require evidence satisfactory
         to it and its counsel that the assets are free and clear of any and all
         security interest, except as set forth herein.

10.      COLLATERAL AUDITS: The Borrower, at the Borrower's expense, shall
         permit the Bank to examine the Borrower's books and records and perform
         audits two times per year or at any time upon reasonable notice. Should
         an out-of-trust situation occur, the Bank expects an immediate payment
         to cure this default.

11.      INSURANCE: The Borrower will provide fire and extended coverage
         insurance on all insurable assets during the term of this commitment,
         satisfactory to the Bank as to form and insurer, containing the
         standard mortgagee and loss payee clauses in favor of the Bank. The
         amount of such coverage will not be less than 80% of the insurable
         value of the assets or 100% of the loan amount, whichever is greater.
         The insurance will be in effect evidenced by a certificate of insurance
         submitted to the Bank prior to or at the settlement. The policy shall
         require a thirty (30) day notice of cancellation to the Bank.

12.      EXPENSES: The Borrower shall pay all out-of-pocket costs and expenses
         incurred by the Bank in connection with the financing arrangement
         promptly upon the Bank's submission of a statement to the Borrower.
         This will include, but not be limited to, attorney's fees and costs,
         lien search fees and filing fees.

                                  Exhibits 10-g


<PAGE>


AM Communications, Inc.                      3                          06/29/99

13.      DOCUMENTATION: Borrower shall duly execute and deliver such
         instruments, documents, certificate, opinions, assurances and do such
         other acts and things as the Bank may reasonable request, to effect the
         purpose of the transaction described in this commitment letter. All
         proceedings, agreements, instruments, documents, and other matters
         relating to the making of the loan, and all of the transactions herein
         contemplated, shall be satisfactory in form and substance to the Bank
         and its counsel. Our counsel must be satisfied with respect to the
         legality, validity, binding effect, and enforceability of all
         instruments, agreements and documents used to effect and consummate the
         loans and transactions herein contemplated.

14.      DUE AUTHORIZATION: The Borrower will obtain all necessary authorization
         of their respective boards of directors and shareholders to enter into
         the agreement evidenced by this letter and will obtain, prior to the
         making of these loans, such further authorization of their respective
         board of directors and shareholders as may be necessary or appropriate
         to the financing arrangement set forth within.

15.      FINANCIAL COVENANTS: The Bank has agreed to waive the financial
         covenant defaults for Minimum Working Capital, Minimum Tangible Net
         Worth; and Maximum Debt to Tangible Net Worth at April 3, 1999. The
         Borrower shall remit a waiver fee to the Bank for $3,000 ($1,000 per
         financial covenant default)
         The Borrower shall maintain the following financial covenants
         throughout the term of this commitment to be test on a quarterly basis
         per GAAP and to be determined:

         a) Minimum Tangible Net Worth of $175,000 at the end of fiscal 2000.

         b) Maximum Net Loss of $650,000 for Q1, $1,000,000 for year to date at
            the end of Q2; $800,000 for year to date at the end of Q3; and
            $175,000 for fiscal 2000.

         c) Minimum Working Capital of $250,000 at the end of Ql; $500,000 at
            the end of Q2; $750,000 at the end of Q3; and $1,000,000 at the end
            of Q4
            Note: The accruals payable to NeST shall be excluded from current
            liabilities for the purpose of testing this covenant, as long as no
            cash payments are made to NeST.

            *Convertible Preferred Stock to be included in Net Worth for
             convenant calculations.

16.      FINANCIAL STATEMENTS: The Borrower shall deliver its annual financial
         statements to the Bank within ninety (90) days after the close of each
         fiscal year during the term of this commitment. The financial
         statements will be audited by an independent accountant satisfactory to
         the Bank. The statements will be prepared in accordance with generally
         accepted accounting principals (GAAP). In addition, the Borrower will
         submit on a monthly basis internally prepared Balance Sheet and Profit
         and Loss Statement, which are prepared in accordance with GAAP.
         Submission of the monthly statements will be within thirty (30) days
         after the end of each period.

                                  Exhibits 10-g


<PAGE>


AM Communications, Inc.                       4                         06/29/99

17.      AGINGS: The Borrower shall deliver is accounts receivable agings to the
         Bank on a monthly basis. Submission of the monthly statements will be
         within fifteen (15) days after the end of each period.

18.      DEPOSIT RELATIONSHIP: The Borrower will maintain Progress Bank as its
         primary bank of account for the term of this commitment. The Borrower
         shall further be required to open a lock box account at Progress Bank
         which shall be utilized throughout the term of this commitment

19.      SATISFACTORY FINANCIAL CONDITION: The Borrower shall maintain, in the
         Bank's judgment, a satisfactory financial condition and shall notify
         the Bank promptly in writing of any material adverse changes in its
         financial condition since the date of issuance of this commitment.

We appreciate the opportunity of making these commitments available to you. If
the terms and conditions outlines herein are acceptable to you, please execute
the acknowledgement on the original of this letter, returning it to the
undersigned in the envelope provided. A copy is enclosed for your records.
Should you have any questions regarding this letter or if the Bank can be of
further service, please feel free to contact the undersigned at (610) 941-4893.

Sincerely,

PROGRESS BANK

Kathleen W. Coviello
Vice President
Specialized Lending

/s/ Kathleen W. Coviello
------------------------

KWC/slp

ACKNOWLEDGEMENT:

We hereby accept the terms and conditions outlined herein this day of
July 1, 1999.

BORROWER:                                AM Communications,

                                         By: /s/ Keith Schneck
                                            -----------------------

                                         Attest: /s/ Patricia Eynin
                                                 ------------------

                                  Exhibits 10-g


<PAGE>




AM Communications, Inc.                       5                         06/29/99

                                  ATTACHMENT I
                                  PROGRESS BANK
                     SECURED LENDING - OPERATING PROCEDURES

This is an outline of the procedures which will facilitate the paperwork that
will flow between your office and the Bank. Normally, what is required will
simply be a by-product of which is already being done by your bookkeeping
department

Borrower's Collateral and Loan Certification: A Borrower's Certification must be
completed monthly, per the terms and conditions stated in the proposal dated
June 29, 1999. Please be sure that accounts receivable are covered on this
report and the balance of the receivables agrees with your control.

Aged Trial Balance: As of the end of each month you are to furnish the Bank with
an Aged Trial Balance of accounts receivable according to their date of origin.
Agings should be mailed on or before the 15th of the following month. Following
is an example of the format to be used for normal terms of 30 days.

A/R Aged Trial Balance as of 5/30/XX

<TABLE>
<CAPTION>
                                             1-30             31-60             61-90             Over 90
Debtor Name                Total             April            March             Feb.              Jan. & Prior
-----------                -----             -----            -----             -----             ------------
<S>                        <C>               <C>              <C>               <C>                 <C>
XYZ Co.                    $7,000            $5,000           $1,000            $500                $500
</TABLE>

Aged Accounts Payable-Trial Balance: Each month and at year end, an aged
accounts payable - trial balance is to be submitted to the Bank, similar in
format of above A/R Aging.

Unqualified Accounts: The following accounts receivable, as well as others
specifically discussed, shall not be considered qualified accounts: (a) contra
accounts, (b) offset accounts, (c) C.O.D. or sight draft accounts, (d)
commission accounts, (e) employee and salesmen accounts, (f) consignment
accounts, (g) guaranteed sales accounts, (h) inter-company accounts, (i) any
amount known to be not readily collectible for any reason, (j) any invoice
without a definite due date, (k) pre-billed invoices, (1) all amounts which are
more than 90 days past invoice date, (m) accounts in litigation or arbitration,
(n) all retainers (including, but not limited to construction retainages), (o)
accounts with 50% or more of the balance 90 days past invoice date, (p) accounts
not generated in the ordinary course of business, (q) interest, (r) finance
charges, (s) accounts arising out of a contract with any department or
instrumentality of the United States of America, unless such account has been
assigned to the Bank under the provisions of the Federal Assignment of Claims
Act, (t) accounts in which the Bank does not have a first lien, and (u) such
other accounts deemed to be unqualified by the Bank. Though the above items are
deemed unqualified for advance purposes, they remain part of the collateral
pledged to the Bank and perfected under the UCC. In computing the unqualified
receivables, in addition to the above, all credit memos are to be added back to
the total unqualified amount.

                                  Exhibits 10-g


<PAGE>


AM Communications, Inc.                        6                        06/29/99

Field Audit: At any time upon reasonable notice, a representative from the
Bank's Field Audit Department will examine your books and records and perform
periodic audits. He will need access to the records of your company to complete
this examination.

Summary: On a monthly basis you are to furnish a Borrower's Certificate
reconciling collateral vs. borrowings at month end.

If you have any questions regarding the correct procedure for the completing of
our forms, please call either myself at (610) 941-4893 or my Assistant Beth
Shemonski at (610) 941-4803. Any and all mail should be addressed to the
attention of Kathleen W. Coviello.

                                  Exhibits 10-g