Hi,
I'm an electrical engineering student looking to restore a couple old
radios. I recently acquired a few including this philco console.
I quickly tore the unit apart expecting to find shorted caps oozing
black goo, broken tubes, missing wires, etc. After checking all the
caps, they seemed fine (says my ohmmeter), xfmrs weren't open/shorted,
etc. I braved up an plugged it in in series with a 150 watt bulb.
After some steel wool on the pins of the RF tubes and a bit of
fiddling, she started to sing. Perfect!
So now that I know it works, I want to refurbish it so it will be
reliable. I have added a new line cord, and am going to buy a fuse
+holder.
I figure I should replace all the caps in the philco-style bakelite
blocks, and those flat metal caps (they're caps right?). I've found
the information for the bakelite block caps, but have yet to figure
out the specs of the flat metal caps. I guess I could just trace the
schematic, but its nice to be able to double check things.
A couple of the resistors seem to have climbed a bit past tolerance
(over 20%), so I'll replace them.
Now for my questions.. Should I replace the large input filter caps?
From what I have read ( a thread from this group circa 2002:
http://tinyurl.com/3oyrxh
) these are oil filled caps, and should be
pretty reliable. They haven't leaked, have high resistance, don't get
warm, and there's no hum. They do seem to fit the description of
being oil caps as the block is quite large, and only houses a couple .
2MF caps. (pic of block. its on the right:
http://www.pithed.org/radios/IMG_0108.JPG
)
Secondly, the wood has not fared as well as the electronics over the
years. My initial thought was to just strip and refinish it, but
after some reading, I keep hearing that salvage is often possible.
Here are some pics, I'd like to know how you guys think I should
attack the refini****ng. I'm not looking for as-new perfect, but I'd
like it to be cleaned up and look proper.
http://www.pithed.org/radios/IMG_0100.JPG
http://www.pithed.org/radios/IMG_0101.JPG
http://www.pithed.org/radios/IMG_0102.JPG
http://www.pithed.org/radios/IMG_0105.JPG
http://www.pithed.org/radios/IMG_0106.JPG
http://www.pithed.org/radios/IMG_0107.JPG
I look forward to your comments.
ps. If anyone is interested, these are the other two radios I bought
at the same time as this philco. All 3 were $20 each.
Sonora D70: http://www.pithed.org/radios/IMG_0109.JPG
Rogers 4424: http://www.pithed.org/radios/IMG_0110.JPG
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