Exhibit
10(a)




First
National Bank




PROMISSORY
NOTE




Principal
              $1,409,847.80
            Loan
      Date
              01-24-2008
            Maturity
              01-24-2013
            Loan
      No.
              8558911
            Call/Coll
            Account
            Officer
              1523
            InitialsReferences
      in the boxes above are for Lender’s use only and do not limit the
      applicability of this document to any particular loan or
item.
              Any
      item above containing “*****” has been omitted due to text length
      limitations.





Borrower:
            M-Tron
      Industries, Inc.
            Lender:
            First
      National Bank of OmahaPiezo
      Technology, Inc.
            
            114th
      & Dodge100
      Douglas Ave.
            
            11404
      W Dodge RDYankton,
      SD  57078
            
            Omaha,
      NE  68154





Principal
      Amount: $1,409,847.80
            Initial
      Rate: 5.385%
            Date
      of Note: January 24, 2008





PROMISE TO
PAY.  M-Tron Industries, Inc.; and Piezo Technology, Inc.
(“Borrower”) jointly and severally promise to pay to First National Bank of
Omaha (“Lender”), or order, in lawful money of the United States of America, the
principal amount of One Million Four Hundred Nine Thousand Eight Hundred
Forty-seven & 80/100 Dollars ($1,409,847.80), together with interest on the
unpaid principal balance from January 24, 2008, until paid in full.




PAYMENT. Subject to any
payment changes resulting from changes in the Index, Borrower will pay this loan
in accordance with the following payment schedule:




Monthly
Principal and interest payments starting 2/24/08 changing monthly based on
floating 30 day Libor plus 210 bps. Final payment of Principal and interest due
on 1/24/13.




Unless
otherwise agreed or required by applicable law, payments will be applied first
to any accrued unpaid interest; then to principal; and then to any late charges.
The annual interest rate for this Note is computed on a 365/360 basis; that is,
by applying the ratio of the annual interest rate over a year of 360 days,
multiplied by the outstanding principal balance, multiplied by the actual number
of days the principal balance is outstanding. Borrower will pay Lender at Lender’s
address shown above or at such other place as Lender may designate in
writing.




VARIABLE INTEREST RATE. The
interest rate on this Note is subject to change from time to time based on
changes in an independent index which is the 30 day Libor Rate per the London
Interbank Offered Rate as quoted in the Wall Street Journal (the “Index”). The
Index is not necessarily the lowest rate charged by Lender on its loans. If the
Index becomes unavailable during the term of this loan, Lender may designate a
substitute index after notifying Borrower. Lender will tell Borrower the current
Index rate upon Borrower’s request. The interest rate change will not occur more
often than each Monthly. Borrower understands that Lender may make loans based
on other rates as well. The
Index currently is 3.285% per annum. The interest rate to be applied to
the unpaid principal balance during this Note will be at a rate of 2.100
percentage points over the Index, resulting in an initial rate of 5.385% per
annum. NOTICE: Under no circumstances will the interest rate on this Note be
more than the maximum rate allowed by applicable law. Whenever increases occur
in the interest rate, Lender, at its option, may do one or more of the
following: (A) increase Borrower’s payments to ensure Borrower’s loan will pay
off by its original final maturity date, (B) increase Borrower’s payments to
cover accruing interest, (C) increase the number of Borrower’s payments, and (D)
continue Borrower’s payments at the same amount and increase Borrower’s final
payment.




PREPAYMENT. Borrower may pay
without penalty all or a portion of the amount owed earlier than it is due.
Early payments will not, unless agreed to by Lender in writing, relieve Borrower
of Borrower’s obligation to continue to make payments under the payment
schedule. Rather, early payments will reduce the principal balance due and may
result in Borrower’s making fewer payments. Borrower agrees not to send Lender
payments marked “paid in full”, “without recourse”, or similar language. If
Borrower sends such a payment, Lender may accept it without losing any of
Lender’s rights under this Note, and Borrower will remain obligated to pay any
further amount owed to Lender. All written communications concerning disputed
amounts, including any check or other payment instrument that indicates that the
payment constitutes “payment in full” of the amount owed or that is tendered
with other conditions or limitations or as full satisfaction of a disputed
amount must be mailed or delivered to: First National Bank of Omaha, PO Box
30207 Omaha, NE 68103-1307.




LATE CHARGE. If a payment is
15 days or more late, Borrower will be charged 3.000% of the regularly scheduled
payment.




INTEREST AFTER DEFAULT. Upon
default, including failure to pay upon final maturity, the interest rate on this
Note shall be increased by adding a 6.000 percentage point margin (“Default Rate
Margin”). The Default Rate Margin shall also apply to each succeeding interest
rate change that would have applied had there been no default. However, in no
event will the interest rate exceed the maximum interest rate limitations under
applicable law.




DEFAULT. Each of the following
shall constitute an event of default (“Event of Default”) under this
Note:




Payment Default. Borrower
fails to make any payment when due under this Note.




Other Defaults. Borrower fails
to comply with or to perform any other term, obligation, covenant or condition
contained in this Note or in any of the related documents or to comply with or
to perform any term, obligation, covenant or condition contained in any other
agreement between Lender and Borrower.




Default in Favor of Third
Parties. Borrower or any Grantor defaults under any loan, extension of
credit, security agreement, purchase or sales agreement, or any other agreement,
in favor of any other creditor or person that may materially affect any of
Borrower’s property or Borrower’s ability to repay this Note or perform
Borrower’s obligations under this Note or any of the related
documents.







Loan No:
      8558911
                  PROMISSORY
      NOTE
                    (Continued)
                  Page
    2
 False Statements. Any
warranty, representation or statement made or furnished to Lender by Borrower or
on Borrower’s behalf under this Note or the related documents is false or
misleading in any material respect, either now or at the time made or furnished
or becomes false or misleading at any time thereafter.


Insolvency. The dissolution or
termination of Borrower’s existence as a going business, the insolvency of
Borrower, the appointment of a receiver for any part of Borrower’s property, any
assignment for the benefit of creditors, any type of creditor workout, or the
commencement of any proceeding under any bankruptcy or insolvency laws by or
against Borrower.




Creditor or Forfeiture
Proceedings. Commencement of foreclosure or forfeiture proceedings,
whether by judicial proceeding, self-help, repossession or any other method, by
any creditor of Borrower or by any governmental agency against any collateral
securing the loan. This includes a garnishment of any of Borrower’s accounts,
including deposit accounts, with Lender. However, this Event of Default shall
not apply if there is a good faith dispute by Borrower as to the validity or
reasonableness of the claim which is the basis of the creditor or forfeiture
proceeding and if Borrower gives Lender written notice of the creditor or
forfeiture proceeding and deposits with Lender monies or a surety bond for the
creditor or forfeiture proceeding, in an amount determined by Lender, in its
sole discretion, as being an adequate reserve or bond for the
dispute.




Events Affecting Guarantor.
Any of the preceding events occurs with respect to any guarantor, endorser,
surety, or accommodation party of any of the indebtedness or any guarantor,
endorser, surety, or accommodation party dies or becomes incompetent, or revokes
or disputes the validity of, or liability under, any guaranty of the
indebtedness evidenced by this Note.




Change In Ownership. Any
change in ownership of twenty-five percent (25%) or more of the common stock of
Borrower.




Adverse Change. A material
adverse change occurs in Borrower’s financial condition, or Lender believes the
prospect of payment or performance of this Note is impaired.




Cure Provisions. If any
default, other than a default in payment is curable and if Borrower has not been
given a notice of a breach of the same provision of this Note within the
preceding twelve (12) months, it may be cured if Borrower, after receiving
written notice from Lender demanding cure of such default: (1) cures the default
within fifteen (15) days; or (2) if the cure requires more than fifteen (15)
days, immediately initiates steps which Lender deems in Lender’s sole discretion
to be sufficient to cure the default and thereafter continues and completes all
reasonable and necessary steps sufficient to produce compliance as soon as
reasonably practical.




LENDER’S RIGHTS. Upon default,
Lender may declare the entire unpaid principal balance under this Note and all
accrued unpaid interest immediately due, and then Borrower will pay that
amount.




ATTORNEYS’ FEES; EXPENSES.
Lender may hire or pay someone else to help collect this Note if Borrower does
not pay. Borrower will pay Lender that amount. This includes, subject to any
limits under applicable law, Lender’s attorneys’ fees and Lender’s legal
expenses, whether or not there is a lawsuit, including attorneys’ fees, expenses
for bankruptcy proceedings (including efforts to modify or vacate any automatic
stay or injunction), and appeals. If not prohibited by applicable law, Borrower
also will pay any court costs, in addition to all other sums provided by
law.




GOVERNING
LAW. This Note will be governed by federal law applicable to Lender and, to the
extent not preempted by federal law, the laws of the State of Nebraska without
regard to its conflicts of law provisions. This Note has been accepted by Lender
in the State of Nebraska.




CHOICE OF VENUE. If there is a
lawsuit, Borrower agrees upon Lender’s request to submit to the jurisdiction of
the courts of the State of South Dakota, in the county in which Borrower’s
following address is located: 100 Douglas Ave, Yankton, SD 57078.




RIGHT OF SETOFF. To the extent
permitted by applicable law, Lender reserves a right of setoff in all Borrower’s
accounts with Lender (whether checking, savings, or some other account). This
includes all accounts Borrower holds jointly with someone else and all accounts
Borrower may open in the future. However, this does not include any IRA or Keogh
accounts, or any trust accounts for which setoff would be prohibited by law.
Borrower authorizes Lender, to the extent permitted by applicable law, to charge
or setoff all sums owing on the debt against any and all such
accounts.




COLLATERAL. Borrower
acknowledges this Note is secured by Security Agreement dated 10/14/2004 on
Blanket Filing on all assets. Loan agreement dated 10/14/2004 and any amendments
thereof.




U.S.A. PATRIOT ACT. IMPORTANT
NOTICE: To help the government fight the funding of terrorism and money
laundering activities, the USA PATRIOT Act requires all banks to obtain and
verify the identity of each person or business that opens an account. When I
open an account you will ask me for information that will allow you to properly
identify me and you will verify that information. If you cannot properly verify
identity within 30 calendar days, you reserve the right to deem all of the
balance and accrued interest due and payable immediately.




ERRORS AND OMISSIONS.ERRORS
AND OMISSIONS. I agree, if requested by you, to fully cooperate in the
correction, if necessary, in the reasonable discretion of you of any and all
loan closing documents so that all documents accurately describe the loan
between you and me. I agree to assume all costs including by way of illustration
and not limitation, actual expenses, legal fees and marketing losses for failing
to reasonably comply with your requests within thirty (30) days.




SWAP AGREEMENT. Swap
Agreement. The parties acknowledge that Borrower may enter into a swap agreement
in connection with the Note, which agreement shall be satisfactory to Lender In
its sole discretion. Any liability or exposure resulting from the swap agreement
will be deemed to be an obligation of Borrower secured by the Loan Documents and
subordinate in repayment to all costs and expenses, interest and principal
described in the Loan Documents.










Loan No:
      8558911
                PROMISSORY
      NOTE
                  (Continued)
                Page
    3
 SUCCESSOR INTERESTS. The terms
of this Note shall be binding upon Borrower, and upon Borrower’s heirs, personal
representatives, successors and assigns, and shall inure to the benefit of
Lender and its successors and assigns.


GENERAL PROVISIONS. If any
part of this Note cannot be enforced, this fact will not affect the rest of the
Note. Lender may delay or forgo enforcing any of its rights or remedies under
this Note without losing them. Each Borrower understands and agrees that, with
or without notice to Borrower, Lender may with respect to any other Borrower (a)
make one or more additional secured or unsecured loans or otherwise extend
additional credit; (b) alter, compromise, renew, extend, accelerate, or
otherwise change one or more times the time for payment or other terms of any
indebtedness, including increases and decreases of the rate of interest on the
indebtedness; (c) exchange, enforce, waive, subordinate, fail or decide not to
perfect, and release any security, with or without the substitution of new
collateral; (d) apply such security and direct the order or manner of sale
thereof, including without limitation, any non-judicial sale permitted by the
terms of the controlling security agreements, as Lender in its discretion may
determine; (e) release, substitute, agree not to sue, or deal with any one or
more of Borrower’s sureties, endorsers, or other guarantors on any terms or in
any manner Lender may choose; and (f) determine how, when and what application
of payments and credits shall be made on any other indebtedness owing by such
other Borrower. Borrower and any other person who signs, guarantees or endorses
this Note, to the extent allowed by law, waive presentment, demand for payment,
and notice of dishonor. Upon any change in the terms of this Note, and unless
otherwise expressly stated in writing, no party who signs this Note, whether as
maker, guarantor, accommodation maker or endorser, shall be released from
liability. All such parties agree that Lender may renew or extend (repeatedly
and for any length of time) this loan or release any party or guarantor or
collateral; or impair, fail to realize upon or perfect Lender’s security
interest in the collateral; and take any other action deemed necessary by Lender
without the consent of or notice to anyone. All such parties also agree that
Lender may modify this loan without the consent of or notice to anyone other
than the party with whom the modification is made. The obligations under this
Note are joint and several.




PRIOR
TO SIGNING THIS NOTE, EACH BORROWER READ AND UNDERSTOOD ALL THE PROVISIONS OF
THIS NOTE, INCLUDING THE VARIABLE INTEREST RATE PROVISIONS. EACH BORROWER AGREES
TO THE TERMS OF THE NOTE.




BORROWER
ACKNOWLEDGES RECEIPT OF A COMPLETED COPY OF THIS PROMISSORY NOTE.




BORROWER:M-TRON
      INDUSTRIES, INC.By:
            /s/
      David Rein
            
            By:_______________,
      ____________________of M-Tron Industries, Inc.
            
            
            _______________,
      ____________________of M-Tron Industries, Inc.PIEZO
      TECHNOLOGY, INC.By:
            /s/
      David Rein
            
            By:Authorized
      Signer for Piezo Technology, Inc.
            
            
            Authorized
      Signer for Piezo Technology, Inc.By:Authorized
      Signer for Piezo Technology, Inc.LENDER:FIRST
      NATIONAL BANK OF OMAHAX
            /s/
      Mark K. McMillanMark
      K. McMillan, Vice President