Subject: TS440 Q33 protection
From: [email-masked] (robert.f.casey)
Date: 10 Dec 91 04:50:38 GMT
Newsgroups: rec.radio.amateur.misc

copied from packet:
 Msg# TSF  Size #Rd  Date  Time From   MsgID        To
 8731 BF   1957   0 08-Dec 0343 KD2EJ  28523_WB2QJA INFO@ALLBBS ()
 Sb: PROTECTING Q-33 ON TS-440S

SB-949
TS-440S PROTECTI   01/20/89

If pin 7 (RL) of the remote connector is accidently
connected to ground, current from the 14 volt line (14L)
will damage transistor Q33 on the IF unit. This will prevent
the radio from transmitting. To protect Q33, a 4.7 ohm
resistor should be installed in series with the RL line on
the foil side of the IF board. In the event that pin 7 is
connected to ground, the resistor will open, but the
transceiver will still be capable of transmitting.

REQUIRED PART:

4.7 OHM, 1/6 WATT RESISTOR ........ RD14CB2C4R7J

1Disconnect the power supply and antenna from the
transceiver.

2Using a #2 Phillips screw driver, remove the 9 screws
from the top cover of the transceiver. Remove the cover
and unplug the speaker wire.

3Locate connector 19 on the IF unit.

4Using a #1 Phillips screw driver, remove the 7 screws
that secure the IF unit to the chassis of the
transceiver.

5Pull the board up and rotate it towards the front of the
transceiver to expose the foil side of the board.

6On the foil side of the board, locate the trace that is
connected to pin 3 (brown wire) of connector 19.

7Using a craft knife, cut the trace comming from pin
three so as to open the foil trace.

8Solder the 4.7 ohm resistor across the now open trace
(i.e. in series with the trace).

9Assemble the transceiver by reversing steps 1 - 5.

This is an optional change that may not be covered under
warranty.
Time required for this modification is 0.5 hrs or less.
(C) 112188TKC
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Note: I haven't tried or verified this, proceed at your own risk.  WA2ISE