From: wa2ise@cbnewsb.cb.att.com (robert.f.casey)
Newsgroups: rec.radio.amateur.misc
Subject: TM221a, no TX in high power mode fix
Keywords: fix
Message-ID: <1991Dec10.045531.26853@cbfsb.att.com>
Date: 10 Dec 91 04:55:31 GMT
Sender: news@cbfsb.att.com
Organization: AT&T Bell Laboratories
Lines: 36


copied from packet:
 Msg# TSF  Size #Rd  Date  Time From   MsgID        To
 8736 BF   1141   0 07-Dec 0512 KD2EJ  28379_WB2QJA INFO@ALLBBS ()
 Sb: TM-221 NO HIGH PWR TXMT.

SB-933

TM-221A No TX in High Power Due to Voltage Drop  4-11-88


Some TM-221A transceivers may intermittently not transmit in
the high power mode.   This condition may be the result of a
voltage drop at the fuse terminals on the power cord.  To 
prevent a voltage drop, solder the terminals by following 
the procedure below.


1Disconnect the antenna and power supply.

2Open and remove the plastic fuse holder.

3Remove the fuse from the terminals.

4Flow solder between the terminals and the exposed
strands of the cable.

5Allow the terminals to cool and then reinstall the
fuse and close the holder.


This modification may be covered under warranty.
Time required for this modification is 0.24 hrs or less.
(c) 42788TKC

===============================================================

   The following is a simple modification for the TM-221 rig:
 
    1- Locate the control unit board (X53-3040-XX)
      located behind the front panel.
 
    2- Right below the channel select rotary switch and opposite the M.IN
      Sw. you will find R24 and R25.(foil side)
 
    3- Remove R25 for 142.00 thru 151.995 Mhz RX TX
 
    4- Move R25 to space for R24 for 138.00 thru 154.000 Mhz TX RX
      (Range will vary slightly from set to set)
 
    Info provided by N2EYR @ WA2SNA-1 / Eddy Salvador

===============================================================

Subject: EXTENDED RANGE !!

THE GET YOUR 221A TO RECIEVE FROM 138-174 MHZ YOU
NEED TO REMOVE THE FRONT PANEL AND GAIN ACCESS TO
THE CHIP RESISTORS AND RE-ARRANGE THEM AS FOLLOWS:

   R22     R23    R24      R25

    X       O      O        X       X = CONNECTED
                                    O = LEFT OUT

IF YOU ARE RUNNING A VK VERSION REMOVAL OF R24 IS
ALL THAT IS NEEDED.  THE TX WILL REMAIN AT 144-148
MHZ EVEN AFTER THE MOD.

73...GEOFF VK3KGH @VK3RPA

=============================================================================



Msg Nr.     : 159459
Da          : EA7FHR
Per         : RIG   @WW      
Tipo/status : BF
Data/ora    : 0302/2346
Dimensione  : 3381
Bid (Mid)   : 21924_EA7FKB
Titolo      : Alcune modifiche per il TM221

Newsgroups: rec.radio.amateur.misc
Subject: TM221a, no TX in high power mode fix
Keywords: fix
Message-ID: <1991Dec10.045531.26853@cbfsb.att.com>
Date: 10 Dec 91 04:55:31 GMT
Sender: news@cbfsb.att.com
Organization: AT&T Bell Laboratories
Lines: 36


copied from packet:
 Msg# TSF  Size #Rd  Date  Time From   MsgID        To
 8736 BF   1141   0 07-Dec 0512 KD2EJ  28379_WB2QJA INFO@ALLBBS ()
 Sb: TM-221 NO HIGH PWR TXMT.

SB-933

TM-221A No TX in High Power Due to Voltage Drop  4-11-88


Some TM-221A transceivers may intermittently not transmit in
the high power mode.   This condition may be the result of a
voltage drop at the fuse terminals on the power cord.  To 
prevent a voltage drop, solder the terminals by following 
the procedure below.


1Disconnect the antenna and power supply.

2Open and remove the plastic fuse holder.

3Remove the fuse from the terminals.

4Flow solder between the terminals and the exposed
strands of the cable.

5Allow the terminals to cool and then reinstall the
fuse and close the holder.


This modification may be covered under warranty.
Time required for this modification is 0.24 hrs or less.
(c) 42788TKC
===============================================================
Note: I haven't tried or verified this, proceed at your own risk. WA2ISE


 Copied from t73he QRZ! Windows Ham Radio CDROM 
73S DE  JERONIMO  EA7FHR @EA7FKB.EAAL.ESP.EU.