Exhibit 10

January 12, 2005

Mr. Mack Traynor, President & CEO
HEI, Inc.
1495 Steiger Lake Lane
Victoria, MN 55386

Dear Mack:

Thank you for the on-going opportunity to provide a revolving credit facility
for HEI, Inc. This letter serves to confirm the continuing availability of the
credit facility provided to HEI, Inc. by Beacon Bank pursuant to the Accounts
Receivable Agreement dated May 29, 2003, on the following terms and conditions:

             
Maximum Client Account Limit:
  $5,000,000
 
           
Discount:
  Immediate discount of .50% and a daily discount of 1/25 of 1%
 
           
Part Payment:
  80% of invoice amount, subject to the completion of appropriate verification
due diligence
 
           
Terms of Contract:
  January 1, 2006
 
           
Account Relationship:
  That the primary deposit relationship for HEI, Inc. be maintained with Beacon
Bank while this credit facility is in place
 
           
Credit Guarantee:
  90-day recourse
 
           
Collateral:
  First security interest in all accounts receivable, inventory, and general
intangibles
 
           
Guaranty:
  Validity guaranty are required from:

      •   Mack Traynor, President & CEO

      •   Doug Nesbit, Chief Financial Officer

 

--------------------------------------------------------------------------------

 

January 12, 2005
HEI, Inc. Commitment Letter
Page 2 of 2

It has been our pleasure working with you and your staff during the last year.
We congratulate your accomplishments this year, and look forward to future
successes for HEI.

As you know, we will also continue to provide HEI, Inc. accounts receivable
credit and collection services, including the management of outstanding accounts
receivable balances, assistance in the development of underwriting policies,
credit approval procedures, and a full complement of accounts receivable and
cash receipts reporting.

All terms and conditions are covered in the Accounts Receivable Agreement.
Please let me know if you have any questions, or if I can be of any further
assistance. As always, we appreciate your business!

Sincerely,

Dave L. Peterka
Executive Vice President

Copy:  Partner Plusm
C/O: Karen Turnquist and Jason Lund
5217 Wayzata Boulevard #120
     Minneapolis, MN 55416