SECURED PROMISSORY NOTE


U.S. $1,800,000.00                                                  May 13, 2004

     FOR VALUE RECEIVED, the undersigned KARLNET, INC., a Delaware corporation
with a principal place of business at 525 Metro Place N, Suite 100, Dublin, Ohio
43017 (the "Obligor"), promises to pay to YDI WIRELESS, INC., a Delaware
corporation with a principal place of business at 8000 Lee Highway, Falls
Church, Virginia 22042 (together with its successors, assigns, and any future
holder or holders of this instrument collectively the "Lender"), or order, at
Lender's place of business or at such other place as the holder of this Note may
from time to time designate, the principal sum of One Million Eight Hundred
Thousand Dollars ($1,800,000.00), in lawful money of the United States of
America in immediately available funds, together with interest at the rate of
eight and one-half percent (8.50%) per annum on the outstanding principal
balance of this Note from the date hereof until such outstanding principal is
paid in full.

     This Note reflects the secured loan being made by the Lender to the Obligor
referred to in the Agreement and Plan of Merger, dated as of the date hereof
(the "Merger Agreement"), among, inter alia, the Obligor, the Lender, and KFire
      ----------------           ----- ----
Merger Corporation ("Merger Sub") pursuant to which the Obligor is merging with
                     ----------
and into Merger Sub. Execution and delivery of this Note is a condition
precedent to the obligation of the Lender to consummate the transactions
contemplated in the Merger Agreement. The obligations of the Obligor under this
Note are secured by the Security Agreement, dated as of the date hereof (the
"Security Agreement"), between the Obligor and the Lender.
 -------------------

     Scheduled Payments. Interest shall be payable monthly in arrears, the first
     ------------------
such payment of interest to be due and payable on June 1, 2004 and continuing on
the same day of each succeeding month. Principal shall be due and payable in
full in a single payment on June 1, 2006 unless extended by the Lender, as
determined in its sole and absolute discretion, by written notice to the
Obligor. Interest will be computed on the basis of a year of 365 days for the
number of days actually elapsed.

     If any payment on this Note becomes due and payable on a Saturday, Sunday
or legal holiday in Virginia, the maturity thereof shall be extended to the next
succeeding business day. Upon the consent in writing of the holder of this Note,
the maturity date for any payment due hereunder may be extended to such date as
may be specified in the written consent. Overdue principal and, to the extent
permitted by applicable law, interest will bear interest at the rate specified
above plus five percent (5%) per annum.

     The Obligor may prepay all or any portion of the amounts due hereunder
without penalty. Except as the holder (in its sole discretion) may otherwise
elect, payments received by the holder from the Obligor on this Note shall be
applied, first, to any costs, expenses or charges then owed the holder by the
Obligor, second, to accrued and unpaid interest, and third, to the unpaid
principal balance hereof.



                                       1
<PAGE>

     The entire principal balance of this Note, together with any unpaid
interest thereon and any other sums due and payable hereunder, shall become
immediately due and payable without notice or demand upon the occurrence of any
of the following events of default: (1) a merger, consolidation, sale of all or
substantially all of the Obligor's assets to another entity or entities in a
single transaction or a series of transactions or any similar transaction; (2)
the liquidation, termination or dissolution of the Obligor or its ceasing to
carry on actively its present business or the appointment of a receiver for any
of its property; (3) the adjudication of bankruptcy or the insolvency of, or the
making of an assignment or trust mortgage for the benefit of creditors by, the
Obligor; (4) the institution of bankruptcy, reorganization, arrangement,
liquidation, receivership, moratorium or similar proceedings by or against the
Obligor, and, if instituted against the Obligor, its consent thereto or the
pendency thereof for 60 days; or (5) any breach or default by the Obligor under
the Merger Agreement or the Security Agreement.

     The Obligor shall pay on demand all costs of collection, including court
costs and reasonable attorneys' fees, suffered or incurred by the holder in
enforcing this Note.

     This Note is assignable only by the holder hereof. No amendment or waiver
of any of the provisions of this Note shall be valid unless in writing and
signed by the holder hereof. Wherever possible, each provision of this Note
shall be interpreted in such a manner as to be effective and valid under
applicable law, but if any provision of this Note shall be prohibited by or
invalid under applicable law, such provision shall be ineffective only to the
extent of such prohibition or invalidity, without invalidating the remainder of
such provision or the remaining provisions of this Note. Whenever in this Note
reference is made to the Obligor, such references shall be deemed to include a
reference to its permitted successors and assigns. The provisions of this Note
shall be binding upon the Obligor and its permitted successors and assigns and
shall inure to the benefit of the Lender.

     The Obligor, guarantors, endorsers or other persons now or hereafter liable
for the payment of any of the indebtedness evidenced by this Note, by making,
guaranteeing or endorsing this Note or by making any agreement to pay any of the
indebtedness evidenced by this Note, waive presentment for payment, protest,
demand, notice of protest, demand and dishonor and nonpayment of this Note, and
all other demands and notices in connection with the delivery, acceptance,
performance, default or enforcement hereof, and consent, without further notice
or assent, on one or more occasions, (a) to the substitution, exchange or
release of the collateral securing this Note or any part thereof at any time,
(b) to the acceptance or release by the holder or holders hereof at any time of
any additional collateral or security for this Note, (c) to the addition,
discharge, release or modification of obligation, in whole or in part, of any
party primarily or secondarily liable hereon, (d) to the modification or
amendment, at any time and from time to time, of this Note and the Security
Agreement or any other instrument securing this Note, (e) to the granting by the
holder hereof of any extension of the time for payment of this Note or for the
performance of the agreements, covenants and conditions contained in this Note,
the Security Agreement or any other instrument securing this Note, and (f) to
any and all forbearances and indulgences whatsoever. Such consent shall not
discharge, alter or diminish the liability of any person.




                                       2
<PAGE>


     No delay or omission on the part of the holder of this Note in exercising
any right hereunder shall operate as a waiver of such right or of any other
right of the holder, nor shall any delay, omission, or waiver on any one
occasion be deemed a bar to or waiver of the same or any other right on any
future occasion.

     THE OBLIGOR HEREBY IRREVOCABLY, KNOWINGLY, VOLUNTARILY AND INTENTIONALLY
WAIVES ANY RIGHTS THAT IT MAY HAVE TO A TRIAL BY JURY IN RESPECT OF ANY
LITIGATION BASED UPON THIS NOTE, ARISING OUT OF, UNDER OR IN CONNECTION WITH THE
TRANSACTIONS WHICH THE NOTE EVIDENCES OR ANY COURSE OF CONDUCT, COURSE OF
DEALINGS, STATEMENTS (WHETHER VERBAL OR WRITTEN) OR ACTIONS BY THE OBLIGOR OR
THE LENDER OR ANY OTHER PARTY RELATING HERETO.

     Any action or proceeding seeking to enforce any provision of, or based on
any right arising out of, this Note may be brought against the Obligor in the
state or federal courts whose local geographic jurisdiction includes Falls
Church, Virginia, and the Obligor consents to the jurisdiction of such courts
(and of the appropriate appellate courts) in any such action or proceeding and
waives any and all rights it may have to contest the appropriateness of any such
action or proceeding, whether based on lack of personal jurisdiction, lack or
insufficiency of service, improper venue, forum non conveniens, or any other
                                          ----- --- ----------
basis. Process in any action or proceeding referred to in the preceding sentence
may be served on the Obligor anywhere in the world.

     This Note shall be governed by and construed according to the laws of the
State of Delaware without regard to principles of conflict of laws.

     Executed as a sealed instrument as of the day and year first written above.

                                                         KARLNET, INC.


                                                         By: /s/ Douglas J. Karl
                                                             -------------------
                                                         Name:  Douglas J. Karl
                                                         Title:  President



                                       3