Low or intermittent receive on the TS-430S may be caused by a poor contact on one or more of the LPF relays. In most cases the following procedure will correct this problem without having to replace relays. The procedure has two steps; first initial cleaning of the contact by passing a relatively high current through them (about 500 mA), and then installing a contact maintenance circuit that will apply a relatively low current (about 8 mA) whenever a new band is selected.
Press and hold the "UP" bandswitch of the TS-430S (ensure the 1 MHz switch is ON).
Apply 13.8V DC to the antenna terminal through the 28 ohm, 10W resistance for approximately 1 minute. This will cycle through all the relays and burn any oxidation/contamination from the contacts.
Contact maintenance circuit installation.
Part List:
Terminal Strip (E22-0371-05)
C1, C2 (CK45D2H473M) .047 �F 500V
C3 (C91-0117-05) .01 �F 50V
L1 (L33-0259-05) 470 �H
R1 (RD14CB2E102J) 1 K ohm 1/4 Watt
Small length of hookup wire, about 6 inches
Disconnect the center lead of the coaxial cable from the antenna terminal.
Install the contact maintenance circuit as shown in the accompanying diagrams.
Attach the terminal lug strip with one of the filter unit cover screws.
(I prefer to add the contact maintenance circuit to
the back side of the filter unit rather than add the terminal strip.)
Solder the 8v lead to the "JP" terminal of the Filter Unit.