05-09-2023, 05:24 PM
Paul,
I have had the occasion to work on similar RCA's. They are well documented in the RCA service notes.
I have experienced open power transformers and split open mica caps as well as IF transformers of which had internal opens to the litz windings. Individual strands, causing broad response. Replacement from salvage was the answer.
The wiring orientation must not change especially the bus wires from the oscillator coil to the band-switch. Even the slightest bend will shift sensitivity/calibration in the high HF bands. The magnetically tuned IF's have a very narrow peak if the windings and the resonating caps are in good condition.
The mica caps in the HF/OSC should be replaced only if the casing is split open and/or the HF/OSC bands do not calibrate properly. Be sure to use metal tubes where called for as capacitance changes will effect sensitivity and calibration.
FWIW, I do not stuff the electrolytics, there is plenty of room for axial or radial filter caps as well as terminal strips under chassis.
GL
Chas
I have had the occasion to work on similar RCA's. They are well documented in the RCA service notes.
I have experienced open power transformers and split open mica caps as well as IF transformers of which had internal opens to the litz windings. Individual strands, causing broad response. Replacement from salvage was the answer.
The wiring orientation must not change especially the bus wires from the oscillator coil to the band-switch. Even the slightest bend will shift sensitivity/calibration in the high HF bands. The magnetically tuned IF's have a very narrow peak if the windings and the resonating caps are in good condition.
The mica caps in the HF/OSC should be replaced only if the casing is split open and/or the HF/OSC bands do not calibrate properly. Be sure to use metal tubes where called for as capacitance changes will effect sensitivity and calibration.
FWIW, I do not stuff the electrolytics, there is plenty of room for axial or radial filter caps as well as terminal strips under chassis.
GL
Chas
Pliny the younger
“nihil novum nihil varium nihil quod non semel spectasse sufficiat”
