TH22AT

copied from the Internet Usenews:
From: forsberg@rainbow.dfw.or.gov (Brent Forsberg)
Newsgroups: rec.radio.amateur.equipment
Subject: TH-22AT Beyond MARS ModificationDate:  November 17, 1993

This procedure will expand the transmit capabilities from 136.000 MHz to
173.995 MHz.

PROCEDURE:

This modification is provided "as is" and is subject to change witwitwithout no
tice.
no warranty of any kind with regard to this modification procedure, including,
but not limited to, the implied warranties of merchantability and fitness for a
particular purpose.  shall not be liable for any error or for incidental or
consequentialdamage in connection with the furnishing, performance, or use of
this modification procedure.

1.  Turn off the power.
2.  Remove the battery pack.
3.  Remove the two long screws from the rear of the rADIO CASE.
4.  Remove the two knobs from the top of the unit.
5.  Remove the rubber top panel.
6.  Squeeze the bottom of the front panel together and gently separate the two
    case halfs.  Use caution so that you do not damage the thin ribbon cable
    connecting the front panel to the main unit.
7.  Remove diode D208.  Located on the circuit board behind the front panel.
    See diagram.
8.  P P Place the diode you just removed [D208] in the location shown for (D212
) and
    solder in place.  Observe proper polarity.  The diode should face the same
    direction as diode D210 and D211.
9.  Reverse steps 1 - 6 to reassemble.
10.  Reset the microprocessor.

CAUTION:  This modification requires soldering equipment rated for CMOS type
circuits.  It also requires familiarity with surface mount soldering techniques
.
If you do not have the proper equipment or knowledge do not attempt this
modification yourself.  Seek qualified assistance.

Time required for this modification is 30 minutes or less.

                !                    ========  W201
                !
                !                =======  W202
                !
                !   ______________
-------------------!              !         [D206]     [D210]
                   !         !
   thin            !    CN203     !         [D207]     [D211]
   ribbon          !                   Q
              !              !         [D208]     (D212)
                   !              !
                   !              !          (D213)
                   !              !
                   !         !
                   !              !
-------------------!______________!                         ____________
                !                         _________________!            !
                !                         !                !            !
                !                         !      SP        !     MIC    !
                !_________________________!_______________!____________!______
                                                 !  !             !  !
                     X57-4370-11 (B/4)