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                                                                  Exhibit 10.40

                                                                 [COMERICA LOGO]

                     [COMERICA BANK--CALIFORNIA LETTERHEAD]

October 8, 1997

Russ Kinsch
Chief Financial Officer
SSE Telecom Inc.
47823 Westinghouse Drive
Fremont, CA 94539

Dear Russ,

Comerica Bank -- California ("Bank") is pleased to commit to SSE Telecom Inc. 
("Borrower") the following updated and amended credit facilities which 
supersede the previous commitments:

FACILITY #1
TYPE/AMOUNT:    $5,000,000 secured revolving line of credit including a within
                line availability for letters of credit up to $1,000,000.

PURPOSE:        To provide cash for short term operating needs and letters of
                credit.

ADVANCE RATE:   a) Borrowing availability is not subject to a formula until the
                utilization, including letters of credit, exceeds $3,000,000 at
                which time the maximum availability would be the lesser of the
                commitment amount or the following borrowing formula:
                i) 80% of eligible accounts receivables, and
                ii) A percentage of raw material inventory, to be determined
                based on an audit performed by the bank, up to a maximum amount
                of $1,000,000, and
                iii) 50% on Echostar stock pledged to the bank and available for
                sale as evidenced by authorization from Echostar.
                Major ineligible receivable categories are defined as contra,
                foreign (unless backed by letter of credit or credit insurance
                acceptable to the bank), affiliated, employee, consignment,
                C.O.D., unbilled, government (unless specifically assigned to
                the bank), over 90 day accounts, accounts from accounts debtors
                with more than 25% of their accounts over 90 days as well as
                concentrations in excess of 20% of the total. BORROWER IS TO
                TAKE OUT INSURANCE COVERAGE OF FOREIGN RECEIVABLES, WHICH
                INSURANCE IS TO BE ACCEPTABLE TO THE BANK.

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                    b) This facility may be converted to a nonformula line of
                    credit provided Borrower maintains a minimum of $6,000,000
                    of accounts receivable at all times and upon achieving two
                    consecutive quarters of increasing minimum profitability
                    defined as achieving operating and net profitability of at
                    least $100,000 in one fiscal quarter and $200,000 in the
                    subsequent fiscal quarter as well as being in compliance
                    with all terms and conditions of the loan agreement.

PRICING:            Prime rate plus .75%
                    .25% p.a. fee. (15 month commitment fee of $15,625).

REPAYMENT:          Interest to be paid monthly. Principal is limited to the
                    lesser of the commitment amount or the borrowing base and is
                    due at maturity.

EXPIRATION:         February 1, 1999.

SECURITY:           Perfected first security interest in accounts receivable,
                    inventory, fixed assets and intellectual property.

OTHER CONDITIONS:

This credit facility would be subject to a preloan audit of accounts receivable
and inventory and would be governed by a loan and security agreement that would
include, but would not be limited to the following:
1) Borrower is to maintain the following financial covenants:
     a)   Minimum quick ratio of .65 increasing to .75 on 3-31-98. These amounts
          are to increase by .05 for every $1 million of after tax proceeds
          received from the sale of Echostar stock.

     b)   Minimum tangible net worth of $23,000,000 increasing by 75% of
          quarterly profits and 100% of new equity and subordinated debt raised
          after the quarter ending 6-30-97. Since the net worth covenant
          includes the before tax value of Echostar stock, the net worth
          covenant will decrease by the amount of taxes paid on the sale of
          Echostar.  THE MINIMUM TANGIBLE NET WORTH COVENANT MAY DECREASE BY
          $4,100,000 DUE TO THE RETIRING OF ECHOSTAR SUBORDINATED DEBENTURES
          FROM THE PROCEEDS FROM THE SALE OF ECHOSTAR STOCK. (THE TANGIBLE NET
          WORTH COVENANT AS OF 6-30-97 IS CALCULATED AS FOLLOWS: $21.1MM IN NET
          WORTH - $.49 MM IN FAIRCHILD INTANGIBLES - $.56MM IN CAPITALIZED
          SOFTWARE + $4.1 MM IN SUBORDINATED ECHOSTAR DEBENTURES = $24.2 MM
          ACTUAL TANGIBLE NET WORTH).

     c)   Maximum debt to tangible net worth of 1.0:1.0.

     d)   Borrower is to be profitable on an operating and after tax basis
          quarterly with the exception of the quarter ending 9-30-97 which may
          be a loss of up to $500,000 and with the exception of any one quarter
          which may be a loss of up to $250,000. Borrower is to be profitable on
          an operating and after tax basis for the fiscal year 1998.

2) Borrower is to provide Bank with:



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     a) Quarterly 10Q within 45 days of quarter end.
     
     b) Annual 10K report and unqualified CPA audited financial statements.

     c) Monthly borrowing base certificate, inventory report, accounts
        receivable and payable agings when utilization exceeds $3,000,000.
        Quarterly accounts receivable and accounts payable agings when on a
        nonformula basis.

     d) Budgets, sales projections or other financial exhibits which Bank may
        reasonably request.

     e) Copies of all SEC documents.

3)   Without Bank's prior written approval, Borrower will not:

     a) Pledge assets other than to Bank except for purchase money transactions
        (leases).

     b) Enter into direct borrowings or guaranties except for normal trade
        credit.

     c) Enter into merger or acquisition.

     d) Declare or pay cash dividends.

     e) Repurchase stock.

     f) Expend more than $2,000,000 in annual capital expenditures.

     g) INVEST MORE THAN AN ADDITIONAL $600,000 IN "OTHER INVESTMENTS" INCLUDING
        MEDIA 4 WHICH INVESTMENT IS TO COME FROM THE PROCEEDS FROM THE SALE OF
        ECHOSTAR STOCK. THIS INVESTMENT IS TO BE CLASSIFIED AS AN INTANGIBLE
        ASSET FOR TANGIBLE NET WORTH COVENANT CALCULATION PURPOSES.

4)   Bank shall have the right to audit Borrower's financial records. The cost
     is for the account of the Borrower.

5)   There shall be a cross default provision between this credit and any
     existing or future credit arrangements.

6)   Out of pocket costs including legal fees, filing fees, etc. incurred are
     for the account of Borrower. However, if standard loan agreement
     documentation is used there will be no legal fees associated with the loan
     agreement portion of the documentation.

7)   Borrower is to maintain its primary depository accounts with Bank.

FACILITY #2
TYPE/AMOUNT:   $1,250,000 non-revolving equipment line of credit. Initially this
               amount will be reserved under the collateral availability
               (Borrowing Base) as defined under the Advance Rate section of the
               revolving line of credit. This loan will amortize as scheduled
               below and will be broken out from the collateral availability
               formula after two consecutive quarters of increasing
               profitability, meeting the debt service requirement and being in
               compliance with the terms and conditions of the loan agreement.

PURPOSE:       To provide financing for the refinancing of the existing Union 
               Bank
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               capital equipment loan and an additional lease.

ADVANCE RATE:  100% of the take out amount for the existing equipment on the
               term loan at Union Bank and an additional lease.

PRICING:       Interest Rate: Prime rate plus .5%
               .25% commitment fee. ($3,125)

REPAYMENT:     Equal monthly principal payments with interest added during the
               36 month amortization period.

MATURITY:      September 30, 2000.

SECURITY:      Lien on all fixed assets. This facility will be cross defaulted
               and cross collateralized to the revolving line of credit
               (Facility #1)

FACILITY #3 
TYPE/AMOUNT:   $500,000 non-revolving equipment line of credit. THIS
               FACILITY BECOMES AVAILABLE AFTER THE COMPANY HAS ONE QUARTER OF
               OPERATING PROFITABILITY, IS MEETING THE DEBT SERVICE REQUIREMENT
               AND IS IN COMPLIANCE WITH THE TERMS AND CONDITIONS OF THE LOAN
               AGREEMENT.

PURPOSE:       To provide financing for new equipment.

ADVANCE RATE:  80% of the invoice price on acceptable newly purchased equipment
               excluding soft costs such as taxes, freight, installation etc.

PRICING:       Interest Rate: Prime rate plus .5%
               .25% commitment fee. ($1,250)

REPAYMENT:     Interest only during the drawdown period followed by equal
               monthly principal payments with interest added during the 36
               month amortization period.

DRAWDOWN:      Latest drawdown date June 30, 1998

MATURITY:      June 30, 2001.

SECURITY:      Lien on all fixed assets. This facility will be cross defaulted
               and cross collateralized to the revolving line of credit
               (Facility #1)

CONDITIONS:
The non-revolving equipment loans (FACILITIES #2 AND #3) will be governed by 
the loan agreement
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used to document Facility #1. The loan agreement will include financial and
operating covenants including the conditions listed above in Facility #1. In
addition to the terms and conditions in Facility #1 the Borrower is to meet a
minimum quarterly debt service covenant of 1.5 beginning with the quarter ending
12-31-97 defined as follows:

                      NPAT + Depreciation  + Amortization
                      -----------------------------------
                current principal payments on all long term debt

Comerica Bank -- California is pleased to have this opportunity to work with SSE
Telecom Inc., and to provide these credit commitments. We are glad to assist
you in your growth plans and hope that this is the beginning of a long and
mutually beneficial relationship. If the above commitment is satisfactory please
acknowledge your acceptance by signing below and returning this commitment
letter to me along with the commitment fees by October 15, 1997 at which time
this commitment will expire. Upon receipt of the above we will immediately
proceed to schedule and audit, document the loans and review the accounts and
cash management services.

Borrower                                 Bank

SSE Telecom Inc.                         Comerica Bank -- California


by: /s/ Russ Kinsch                      by: /s/ Alan Jepsen
    ---------------------------              -------------------------
Russ Kinsch                              Alan Jepsen
Chief Financial Officer                  Vice President and Assistant Manager