<PAGE>

                                  EXHIBIT 4.6

     This Preferred Security is a Book-Entry Preferred Securities Certificate
within the meaning of the Trust Agreement hereinafter referred to and is
registered in the name of The Depository Trust Company, a New York
corporation (the "Depositary") or a nominee of the Depositary. This Preferred
Security is exchangeable for Preferred Securities registered in the name of a
person other than the Depositary or its nominee only in the limited
circumstances described in the Trust Agreement (as defined below) and no
transfer of this Preferred Security (other than a transfer of this Preferred
Security as a whole by the Depositary to a nominee of the Depositary or by a
nominee of the Depositary to the Depositary or another nominee of the
Depositary) may be registered except in limited circumstances.

     Unless this Preferred Security is presented by an authorized
representative of the Depositary to Spectrum Capital Trust II or its agent
for registration of transfer, exchange or payment, and any Preferred Security
issued is registered in the name of Cede & Co., or such other name as
requested by an authorized representative of the Depositary (and any payment
hereon is made to Cede & Co. or to such other entity as is requested by an
authorized representative of the Depositary), ANY TRANSFER, PLEDGE, OR OTHER
USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as
the registered owner hereof, Cede & Co. has an interest herein.

<TABLE>
<CAPTION>
  Certificate Number                             Number of Preferred Securities
  <S>                                            <C>
      **1**                                                ____________
</TABLE>


                       CUSIP NO. _________________



               Certificate Evidencing Preferred Securities

                                    of

                        Spectrum Capital Trust II


                 _____% Cumulative Preferred Securities

              (liquidation amount $10 per Preferred Security)

<PAGE>

     SPECTRUM CAPITAL TRUST II, a statutory business trust created under the
laws of the State of Delaware (the "Trust"), hereby certifies that Cede & Co.
(the "Holder") is the registered owner of _____________ (____________)
preferred securities of the Trust representing undivided beneficial interests
in the assets of the Trust and designated the _____% Cumulative Preferred
Securities (liquidation amount $10 per Preferred Security) (the "Preferred
Securities").  The Preferred Securities are transferable on the books and
records of the Trust, in person or by a duly authorized attorney, upon
surrender of this certificate duly endorsed and in proper form for transfer
as provided in Section 504 of the Trust Agreement (as defined below).  The
designations, rights, privileges, restrictions, preferences, and other terms
and provisions of the Preferred Securities are set forth in, and this
certificate and the Preferred Securities represented hereby are issued and
shall in all respects be subject to the terms and provisions of, the Amended
and Restated Trust Agreement of the Trust dated as of ______________, 2001,
as the same may be amended from time to time (the "Trust Agreement"),
including the designation of the terms of Preferred Securities as set forth
therein.  The Holder is entitled to the benefits of the Preferred Securities
Guarantee Agreement entered into by Spectrum Bancorporation, Inc., an Iowa
corporation, and Wilmington Trust Company, as guarantee trustee, dated as of
_____________, 2001 (the "Guarantee"), to the extent provided therein.  The
Trust will furnish a copy of the Trust Agreement and the Guarantee to the
Holder without charge upon written request to the Trust at its principal
place of business or registered office.  Upon receipt of this certificate,
the Holder is bound by the Trust Agreement and is entitled to the benefits
thereunder.

     IN WITNESS WHEREOF, one of the Administrative Trustees of the Trust has
executed this certificate this ___ day of __________, 2001.

                                 SPECTRUM CAPITAL TRUST II





                                 By:

                                     ----------------------------------------
                                     Daniel A. Hamann, Administrative Trustee