06-11-2019, 08:09 PM
If the lozenge shaped mica caps were replaced. Then a complete alignment is required. Any piston cap. adjuster that has no effect, that L/C circuit associated with it has a problem. Any IF can that the slug tuning is very broad, has broken wires in the litz windings and/or leaking/drifted tuning cap. The values posted for the Lozenge caps are not necessarily the ones used. RCA tuned the radio by using cap values that worked for the radio. If any of the wiring was disturbed in the RF/OSC sections including that in/out of the band switch could seriously miss align the radio. FWIR this radio has rubber wiring.
Was the band switch sprayed with "sooper-gloopo Tuner cleaner", WD-40 or similar? Saturated band switch wafers will have a serious effect on sensitivity. Some radios have B+ on contacts, could easily arc and burn out the band switch. De-gook with 91% propanol alcohol, stuff from Walmart, pack clean cotton rag carefully under band switch to catch excess, use an acid brush to scrub the wafers and the center blades. Blow dry with gentile compressed air. Do not tun o power until completely dry and any bristles from brush removed...
If any tube sockets got the same treatment do the same cleaning.
Do check the Antenna coils on all bands, an open coil can be a problem.
If this chassis uses any chassis grounds via a rivet, solder this rivet to the chassis or drill out use fresh hardware with toothed washers. FWIR RCA uses a punched tang from the chassis for grounds but that may not be so in the RF/OSC sections.
GL
Chas
Was the band switch sprayed with "sooper-gloopo Tuner cleaner", WD-40 or similar? Saturated band switch wafers will have a serious effect on sensitivity. Some radios have B+ on contacts, could easily arc and burn out the band switch. De-gook with 91% propanol alcohol, stuff from Walmart, pack clean cotton rag carefully under band switch to catch excess, use an acid brush to scrub the wafers and the center blades. Blow dry with gentile compressed air. Do not tun o power until completely dry and any bristles from brush removed...
If any tube sockets got the same treatment do the same cleaning.
Do check the Antenna coils on all bands, an open coil can be a problem.
If this chassis uses any chassis grounds via a rivet, solder this rivet to the chassis or drill out use fresh hardware with toothed washers. FWIR RCA uses a punched tang from the chassis for grounds but that may not be so in the RF/OSC sections.
GL
Chas
Pliny the younger
“nihil novum nihil varium nihil quod non semel spectasse sufficiat”
