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Cabinet and Electronic Restoration
#6

Hi Scott,

Unfortunately, I can't take on fixing this radio at this point in time. However, I and others will be glad to help on this website. Are you comfortable reading schematics? Do you know how to solder? Are you looking to repair the chassis or do a museum quality restoration?

Repairing an antique radio requires at a minimum:
-Replacing the electrolytic capacitors (those long metal cans, #62 and 60 on the schematic). Disconnect
the wires from the old ones before connecting to replacements. the new ones are much smaller than the
old ones. An expert restorer, doing a museum quality restoration will hollow out the original "cap"
(capacitor) and install the new ones inside. These caps (especially this variety) short when they get old.
Failure to replace them would cause a short in the "B+ supply, destroying the rectifier and power
transformer.

-Replace the 2 caps marked 67 on the schematic with "safety caps" or just remove them for now if you
don't have replacements. They provide noise suppression. However, if they short and old caps short), this
will make the chassis electrically "hot".

-Replace all of the "paper" capacitors. These may be in Bakelite blocks. The blocks have to be removed
and hollowed out. There are many threads in the Phorum on how to do this. you can use the blocks as
terminals and tack the new ones on the terminals, but the connection must be broken to the original caps
inside the block. A drill bit passed through the rivet should break the wire connecting the innards to the
terminals. Make sure that if the block contains more than one cap or contains a resistor, that these parts
are also replaced.

-Replace any resistor whose measured value is more than 20% different than the specified value.

-Replace the power cord. Add a fuse on the switched side of the cord. Fuse for 1.5 X the rated current
with a fast (AGC) fuse.

-Replace any wiring whose insulation has deteriorated. This usually occurs to rubber wire, and your radio
may contain rubber insulated wire.

Based on the pix you posted:
-The speaker needs to be repaired and likely re-coned.
-The "grille cloth" must be replaced
-The power cord must be replaced.

Getting to the tuner sub-chassis may be difficult.

Also note that your rectifier is the uncommon 5Y4, not the more common 5Y3. They are not directly interchangeable die to different pin connections for the plates. rewiring is necessary to replace a 5Y4 with a 5Y3.

If you don't do this yourself or get a hobbyist friend to do this for you, a pro job is going to be expensive, but this is an heirloom and a good performing, rather sensitive radio.

"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
"Let us begin to do good"- St. Francis

Best Regards, 

MrFixr55


Messages In This Thread
Cabinet and Electronic Restoration - by ches2195 - 01-21-2023, 07:37 PM
RE: Cabinet and Electronic Restoration - by MrFixr55 - 01-22-2023, 08:25 PM
RE: Cabinet and Electronic Restoration - by morzh - 02-12-2023, 04:14 PM



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