TS120.1

TS-120S FULL CW OUTPUT IN SSB MODE

Hight reverse leakage, ou shorting of D2 and sometime D3 on the RF UNIT X44-1260-01, will provide an unwanted DC voltage path which gives full CW output while in the SSB mode. Carrier control has no effect, and RX is not affected.

Replace D2, 1S2588, check D3, 1s1587, and install an additional diodo, D8, a 1S1585 on the foil side of the RF unit.

To install, swing the rf unit up. Remove the shield from under the IF unit, exposing the foil side of the RF unit.
Using a razor or X-ACTO Knife, carefuly cut the land between C4 and C20.
Solder the additional 1S1585 across the the cut and observe polarity
Replace D2, the 1S2588. Some RF units have a 12 PF cap soldered on the foil side of the board, across T1; C20 will be missing.
Remove the 12 PF cap, and install C20, 33 PF in the board.

Production later than 080001 has this change.