Exhibit 10.18

                                 PROMISSORY NOTE

Principal   Loan Date   Maturity   Loan No. Call   Collateral  Account   Officer
$3,500,000. 12-21-1997  06-30-1999 47886    220    40,42       0206190    DRB
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References  in the shaded  area are for  Lender's use only and do not limit the
applicability of this document to any particular loan or item.
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Borrower: Tower Tech, Inc.(TIN:73-1210313)  Lender: Southwestern Bank & Trust Co
          P.O.  Box 1838                            8000 South Western Ave.
          Chickasha, OK 73023                       P.O. Box 19100
                                                    Oklahoma City, OK 73138


Principal Amount: $3,500,000.00     Initial Rate: 10.500%
Date of Note: December 31, 1997

PROMISE TO PAY.  Tower Tech Inc.  ("Borrower")  promises to pay to  Southwestern
Bank & Trust Company ("Lender"),  or order, in lawful money of the United States
of America, the principal amount of Three Million,  Five Hundred Thousand 00/100
DoIIars ($3,500,000.00) or so much as may be outstanding, together with interest
on the unpaid outstanding  principal balance of each advance.  Interest shall be
calculated from the date of each advance until repayment of each advance.

PAYMENT.  Borrower  will pay this loan on demand or if no demand is made; in one
payment of all  outstanding  principal plus all accrued unpaid  interest on June
30, 1999.  In addition,  Borrower will pay regular  monthly  payments of accrued
unpaid interest beginning January 31, 1998, and all subsequent interest payments
are due on the  same  day of each  month  after  that.  Interest on this Note is
computed on a 385/360 simple interest  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.  Unless otherwise agreed or
required by applicable  law,  payments  will be applied first to accrued  unpaid
interest,  then to principal,  and any remaining amount to any unpaid collection
costs and late charges.

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  National
Prime (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 notice to Borrower.  Lender
will tell  Borrower the current  Index rate upon  Borrower's  request.  Borrower
understands  that  Lender  may make  loans  based on  other  rates as well.  The
interest  rate  change  will not occur  more  often  than  each  day.  The Index
currently  is 8.500% per annum.  The  interest  rate to be applied to the unpaid
principal balance of this Note will be at a rate of 2.000 percentage points over
the Index,  resulting in an initial rate of 10.500% per annum.  NOTICE: Under no
circumstances  will the interest rate on this Note be more than the maximum rate
allowed by applicable law.

PREPAYMENT;  MINIMUM INTEREST CHARGE. In any event, even upon full prepayment of
this Note,  Borrower  understands  that Lender is entitled to a minimum interest
charge of $7.50.  Other than Borrower's  obligation to pay any minimum  interest
charge,  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
at accrued unpaid interest. Rather, they will reduce the principal balance due.

DEFAULT.  Borrower  will  be in  default  if any of the  following  happens  (a)
Borrower  fails to make any payment when due.  (b)  Borrower  breaks any promise
Borrower has made to Lender, or Borrower fails to comply with or to perform when
due any other term,  obligation,  covenant, or condition contained in this Note,
or any  agreement  related  to this  Note,  or in any  other  agreement  or loan
Borrower has with Lender.  (c) Borrower  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.  (d) Any
representation  or  statement  made or  furnished  to Lender by  Borrower  or on
Borrower's  behalf is false or misleading in any material  respect either now or
at the time made or furnished.  (e) Borrower  becomes  insolvent,  a receiver is
appointed for any part of Borrower's property,  Borrower makes an assignment for
the benefit of creditors,  or any proceeding is commenced  either by Borrower or
against Borrower under any bankruptcy or insolvency laws. (f) Any creditor tries
to take any of Borrower's  property on or in which Lender has a lien or security
interest. This includes a garnishment of any at Borrower's accounts with Lender.
(g) Any  guarantor  dies or any of the other  events  described  in this default
section occurs with respect to any guarantor of this Note or any guarantor seeks
claims or  otherwise  attempts  to limit,  modify  or  revoke  such  guarantor's
guarantee  of this Note.  (h) A material  adverse  change  occurs in  Borrower's
financial  condition,  or Lender believes the prospect of payment or performance
of the indebtedness is impaired. (i) Lender in good faith deems itself insecure.

LENDER'S  RIGHTS.  Upon default,  Lender may declare the entire unpaid principal
balance on this Note and all accrued unpaid interest  immediately  due,  without
notice, and then Borrower will pay that amount. Upon default,  including failure
to pay upon final maturity,  Lender, at its option, may also, if permitted under
applicable  law,  increase  the  variable  interest  rate an this  Note to 7.000
percentage  points over the Index. The interest rate will not exceed the maximum
rate  permitted by applicable  law.  Lender may hire or pay someone else to help
collect this Note if Borrower  does not pay.  Borrower also 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  and  legal  expenses  for  bankruptcy   proceedings
(including  efforts  to modify  or vacate  any  automatic  stay or  injunction),
appeals,  and  any  anticipated   post-judgment   collection  services.  If  not
prohibited by applicable law, Borrower also will pay any court costs in addition
to all other sums  provided by law.  This Note has been  delivered to Lender and
accepted  by Lender in the State of  Oklahoma.  If there is a lawsuit,  Borrower
agrees  upon  Lender's  request to submit to the  jurisdiction  of the courts of
Oklahoma  County,  the State or  Oklahoma.  This Note shall be  governed  by and
construed in accordance with the laws of the State or Oklahoma.

RIGHT OF SETOFF.  Borrower  grants to Lender a contractual  possessory  security
interest  in, and hereby  assigns  conveys  delivers,  pledges and  transfers to
Lender all Borrower's right,  title and interest in and to, Borrower's  accounts
with Lender (whether checking, savings or some other account), including without
limitation all accounts held jointly with someone else and all accounts Borrower
may open in the future,  excluding  however all IRA and Keogh  accounts  and all
trust accounts for which the grant of a security interest would be prohibited by
law. Borrower  authorizes  Lender, to the extent permitted by applicable law, to
charge or setoff all sums owing on this Note against any and all such accounts

COLLATERAL  This Note is  secured  by All  Borrower's  accounts  other than
accounts  arising from sales to foreign (i.e.  not U.S.)  nationals,  inventory,
general  intangibles and rental fleet  inventory;  US. Patent no.  5,487,849 end
U.S. Patent no. 8,487,53l; Assignment of Life Insurance on Harold Curtis.


LINE OF CREDIT.  This Note evidences a revolving line of credit.  Advances under
this Note may be requested  orally by Borrower or as provided in this paragraph.
Lender  may,  but need not,  require  that all oral  requests  be  confirmed  in
writing.  All  communications,  instructions,  or  directions  by  telephone  or
otherwise  to Lender are to be directed  to Lender's  office  shown  above.  The
following  party or parties are authorized  as  provided  in this  paragraph  to
request advances under the line of credit until Lender receives from Borrower at
Lender's  address shown above written  notice of revocation of their  authority:
Charles D.  Whitsitt,  Chief  Financial  Officer.  Advances  under this note are
subject  to the  conditions  and  limitations  set  forth in the  Business  Loan
Agreement  of even date  herewith.  Borrower  agrees  to be liable  for all sums
either: (a) advanced in accordance with the instructions of an authorized person
or (b) credited to any of Borrower's  accounts with Lender. The unpaid principal
balance owing on this Note at any time may be evidenced by  endorsements on this
Note or by Lender's  internal  records,  including  daily  computer  print-outs.
Lender will have no obligation to advance funds under this Note if: (a) Borrower
or any  guarantor  is in default  under the terms of this Note or any  agreement
that Borrower or any guarantor has with Lender  including any agreement  made in
connection  with the signing of this Note; (b) Borrower or any guarantor  ceases
doing  business or is  insolvent;  (c) any  guarantor  seeks claims or otherwise
attempts to limit,  modify or revoke such guarantor's  guarantee of this Note or
any other loan with Lender;  (d) Borrower has applied funds provided pursuant to
this Note for purposes  other than those authorized  by Lender; or (e) Lender in
good faith deems itself insecure under this Note or any other agreement  between
Lender and Borrower.

GENERAL  PROVISIONS.  This Note is payable on demand.  The inclusion of specific
default  provisions  or rights of Lender  shall not preclude  Lender's  right to
declare payment of this Note on its demand.  Lender may delay or forgo enforcing
any of its rights or remedies under this Note without losing them.  Borrower and
any other  person who signs  guarantees  or  endorses  this Note,  to the extent
allowed by law,  waive  presentment,  demand for payment,  protest 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.

12-51-1997                   PROMISSORY NOTE                              Page 2
                               (Continued)
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PRIOR TO S1GNING THIS NOTE,  BORROWER READ AND  UNDERSTOOD ALL THE PROVISIONS OF
THIS NOTE,  INCLUDING THE VARIABLE INTEREST RATE PROVISIONS.  BORROWER AGREES TO
THE TERMS OF THE NOTE AND ACKNOWLEDGES RECEIPT OF A COMPLETED COPY OF THE NOTE.

BORROWER:

Tower Tech, Inc.

By: ss/CHARLES D. WHITSIT
___________________________________________
Charles D. Whitsitt. Chief Financial Officer