GE Tombstone Radio A-63

[healyc139]

Hey there everybody reading this!

I have my hands on a 1930's Tombstone radio, an A-63 to be precise. I have gone through and kinda broken things down to get a better look at everything. From what I can see; this is most likely going to be a full rebuild.. I have what I think are all the capacitors and resistors written down, but I am having trouble finding all of the components. I guess my initial question is this; does anybody have any experience with these radios? I'm still shopping for parts, but the items I am having trouble finding are below. Maybe there are close equivalents that I could source? That silver box is also a concern.. the one that says '4-8mfd 25VDC & 4mfd 450VDC. That looks like a can capacitor but I don't want to assume.

Can't find:
.08uf 450v Cap
8uf 475v Cap
.01uf 200v Cap
.05uf 200v Cap
.02uf 200v Cap
.1uf 200v Cap

Maybe this radio isn't even worth fixing up? Not sure since there is not a lot of info for this model online.

Any help or advice would be great!

 

[s-petersen]

all of the .??mfd caps can be replaced with 630v polypropylene rounded to the closest modern equivalents like the .05 cap is replaced with .047 .02uf would be .022 .08uf would be .082 etc..
The 8 mfd electrolytic, or paper would be a 10mfd @ 500v, the 4mfd @450 is likely paper, and could be replaced with (2) 2.2mfd @630v polypropylene caps in parallel

 

[Dave451]

Nice old radio--love these old cabinets, but what a nest inside! Most of the values you can't find are available in 400V or 630V film types--it's OK to use the higher voltages in place of the 200V, etc. 10 uF 475VDC would probably be OK for the 8 uF unit. Tolerances on the old electrolytics were often -20%/+50%. OK to use more modern values in some instances, like 0.047 for 0.05 uF. 0.022 for 0.02. Well within the tolerances for these old radios. The 'silver box' is no doubt an electrolytic--replace with individuals of same value. Is the "4-8" two separate segments?

Looks worth it to me--good luck with it!

 

[AlTinkster92]

Try Mark Oppat at Old radio parts, he has parts for all kinds of this sort of thing.....hard to get ahold of at times..

 

[s-petersen]

After looking at the pics, Dave451 is likely correct on the 4mfd being electrolytic. be extremely careful around those coils, I recommend putting the covers back on to protect them.

 

[Dave451]

Just Radios in Canada also a good source (no affiliation).

 

[healyc139]

After looking at the pics, Dave451 is likely correct on the 4mfd being electrolytic. be extremely careful around those coils, I recommend putting the covers back on to protect them.

Very good advice, they seem very delicate for sure. There are some resistors on them which I think I'll have to replace. They all look like lego's, not like they do today so I assume they need the boot.

 

[s-petersen]

Do not remove them, I am pretty sure they are mica caps, If you change anything on the coils, the radio will certainly need realignment. Pics of the "resistors" please.
My advice would be to just replace the electrolytic caps first, then see if the radio works, If it does, even poorly, replace a few of the coupling caps at a time and retest, then move on to checking and replacing out of spec resistors, if the radio is not working satisfactorily.

 

[healyc139]

Wow thanks so much for the quick responses everybody, this has been a great help already!

 

[healyc139]

Do not remove them, I am pretty sure they are mica caps, If you change anything on the coils, the radio will certainly need realignment. Pics of the "resistors" please.
My advice would be to just replace the electrolytic caps first, then see if the radio works, If it does, even poorly, replace a few of the coupling caps at a time and retest, then move on to checking and replacing out of spec resistors, if the radio is not working satisfactorily.

The picture attached is of the component that I thought might be a resistor. GE radio 6 has an arrow pointed at what I think is a resistor. GE radio 5 has the same looking component but it is on the underside of the chassis.

 

[s-petersen]

That is a mica capacitor, they rarely go bad, although there were some paper in that shape, it depends on the color of one of the dots, I don't remember which one off-hand

 

[healyc139]

That is a mica capacitor, they rarely go bad, although there were some paper in that shape, it depends on the color of one of the dots, I don't remember which one off-hand

Ah ok, that's awesome if I don't have to replace those. I'll take a closer look tonight and see if I can find any indication on it being paper or not. Is there an easy way (other than the component having it printed right on its side) to tell the electrolytic from the couplers? These all kinda look like old couplers :|

 

[gadget73]

Someone has been into this one. That Sprague black cap in the middle is newer than the rest. It probably dates from the 50s, positively modern stuff. Not sure about that box either, it doesn't look like it belongs unless the mounting screws have been removed before the pic was taken. Same with that other wired cap with the "ears" strapped to the back. I'm reasonably sure that should have had an aluminum can cap on top of the chassis through the open hole in the rear corner.

Generally electrolytic caps are going to be in whole numbers, paper caps are in decimals.

The domino caps in paper are usually larger, but they are also a 6 dot code. The first dot tells what its made off. Off the top of my head I want to say white or black is mica, anything else is paper.

 

[s-petersen]

Electrolytic caps are generally over 1uf (mfd) and are polarized, the others are not. This is for older tube equipment.There are some paper caps on pre 40's radio's that are like blocks mounted on the chassis,
and some paper in oil caps on higher end and military equipment that are all metal.

 

[s-petersen]

I have seen that same square box electrolytic used in a 1928 Zenith radio, as a repair

 

[Pio1980]

I have seen that same square box electrolytic used in a 1928 Zenith radio, as a repair

Older than the tubular with the clamp, the both probably need to go and perhaps the original restuffed. Bad chassis grounding points can cause problems, including coil cans.

 

[Big Harry]

I have the service information for your radio in my Riders manual book 6. If you need it, I can scan it for you. The square box electrolytic caps were common in the 30's and 40's and can be replaced with modern caps by either re stuffing the boxes or replacing with modern caps if originality isn't a problem.

 

[infullview]

The cabinet is in beautiful shape. This radio is well worth restoring. I've restored a number of cathedral radios. You can find schematics at https://www.radiomuseum.org/r/general_el_a63_1.html

 

[maxhifi]

I restored a Canadian GE A-70, which has a very similar cabinet, but also includes a magic eye tube. The performance is fantastic, and I use it a lot. On mine I changed all the paper and electrolytic caps, one noisy mica, cleaned the controls, put some heat shrink over a few damaged rubber wires, and changed three tubes.

Make sure you do use a 500V cap to replace that first filter, or do what I did and use two 300V caps in series. The voltage is so high because the field coil drops a lot of voltage.

Agree with others, put the covers back on those IF cans and don't take them off unless need arises, the coils are delicate and made of pure unobtainium.

 

[healyc139]

Thanks for the advice everybody! It is going well so far. I am wondering what those long red and long green things are now. The green one that says 5M OHMS. Worth replacing?