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41-604 electrolytic
#1

Hi all,
I have recapped the 41-604. I also replaced the cord and tested the tubes.

I have neither a variac nor a dim bulb tester, so I plugged it into the wall. The bulb blew, and that was it.

After going over it again and checking all of my soldering; I now get a hum, crackling, and the smell of burning (I quickly unplugged it).

Now, back to the drawing board.

As part of this, I wanted to ask about the electrolytic. The one that came with the radio was clearly a replacement (it was an unmarked aluminum can outside the chassis). Am I correct that my replacement should be two 22uF electrolytics with separate positives but a common negative?

Any insight would be greatly appreciated. Thanks in advance!

http://www.nostalgiaair.org/pagesbymodel...013429.pdf
#2

schematic won't open,,, SORRY
#3

Let's try that again:
http://www.nostalgiaair.org/Resources/429/M0013429.htm
#4

Hi Nick,
Yes both of the - are connected together and connect to B- (the off/on switch). They don't connect to the chassis. If you did manage to connect the e caps backward they are junk now, replace w/ new.

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry
#5

http://www.nostalgiaair.org/pagesbymodel...013429.pdf

If it blew lamp as soon as powered up there is a short on the heater string...

If after warm up, short is in B+...

Tom
#6

So, I now just get a hum. This is the case regardless of turning on the radio or the phono. I do see the tubes lighting up.

From what I've read, I'm still looking at the e caps and their wiring being the culprit, correct?

I'm quite sure I've got them wired in the correct direction (they're axial, with a nipple preceding the lead on the negative side).
#7

Chances are pretty good that I completely miffed in the recap process.

Here's a pic if anyone cares to take a look:
https://photos.app.goo.gl/fvtNtfPepjQbypYv2
#8

Filters look OK connection wise. So if that isn't the issue that leaves a couple things. Cathode to grid short in one of the tubes (35A5 would be a good candidate). Or you might have miss wire a cap from ac side of thing (Ac line or heater circuit) to the grid circuit of one of the tubes. Or perhaps a bad 35Z3.

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry




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