TS-120s Ant Transformator Replacement: New Part.
Supercedes bulletin #40 7/12/79
Transceivers subject to strong static fields, high RF, or similar high current atmospheric discharges may suddenly exhibit low sensitivity on all bands. TX will not be effected. Suspect T1 on the RF unit, X44-1260-01.
When replacing T1, L43, 0696-35, check that the value of C20 is 33pF. Early units may have a 15pF for C20, and may have T1 as L43-0696-05. In either case, replace the transformer with an L43-0929-15. If C20 is 15pF, replace it with a 33pF capacitor. Since T1 is a broadband transformer, no adjustment is necessary.
In addition, add two 1S1587 diodes after the transformer as shown to further protect the receiver.
Installation time for this procedure is approximately ½ hour.