Restoring my 37-116. It plays now!
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Arran
The one that's there is 5U4G.
I use Hickok 600 and yes it does have a separate button to test rectifiers, and not only for that but for diodes too.
P3 button is the one I press. But even if I was brain-dead the tube chart actually says "P3", so I don't have to do much guessin' at all.
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Only difference is pin 1, but should make no difference in test result.
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That's what I think, I just can't fathom how two tubes of the same kind get to test exactly the same bad, while another one in a different envelope (from the same radio) tests acceptable.
Coincidence, probably, but strange.
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I'm beginning to wonder if the tube tester has some sort of defect like is out of adjustment, or someone played with the wiring, didn't you have a similar occurrence with some 6A8 tubes? If the tester was bought over fleabay you never know what someone has done to it, I've seen all kinds of strange things people have done to test equipment. The tube tester I have which is similar to a Hickock, a Canadian made Stark, has a scale setting switch needed for some tests, it can cause whacky readings if accidentally set wrong. Try testing some tubes out of a working radio and see what happens. If you can find someone with another tube tester and get a second opinion.
Regards
Arran
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Arran
I did test the other tubes.
Those were not 6A8 but 6A7.
I have good tubes and they do test as "good" on it. And when the guy sent the substitue 6A7 it testet practically as new, and the I retested the others and they still tested bad. And notice, the good and bad readings are stable - the same tube tested several times after other trubes have been tested will test the same.
And I have other 6J5, "G" that tests normally (on the low side but acceptable).
If the tester was doctored and the wiring was screwed up, and it results in 6J5GT/G testing bad the 6J5G will also test bad - there is no electrical difference there that would explain it.
And, yes, I looked inside the tester. I did not see any signs of tampering with panels or switches. If anyone took care of something it was done very professionally.
So, no, that does not explain it. I wish it would; then I could go in and fix it.
(This post was last modified: 05-24-2013, 08:12 PM by morzh.)
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Here's the tube line-up when tested to English:
6H6-GT/G - GOOD
6L7G - GOOD
6F6-GT/G - GOOD
6J5G - GOOD (Barely in the Green)
6J5-GT/G - Bad (dead)
6J5-GT/G - Bad (dead)
6K7G - Good
6K7G - Good
6K7G - Good
6K7G - Fair (Question mark)
6A8 Pent. - Fair (Question mark)
Osc - Good
6N7G - Fair (Question mark), Both halves
6A5G - Fair (Question mark)
6A5G - Fair (Question mark)
5U4G - BAD (dead)
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OK, tool apart the tuning mechanismus, boy that's a real....clockwork.
I did it because I want the cap out and I want to throw it in my dishwasher.
The dial is not just cracked, the attachment of the dis to the hub is broken so I am not even sure I can restore it....
The thing is dirty as sin!
That capacitor is indeed solder well.
Now I could use some instructions while disassembling and assembling it back.
Does anyone know of any drawing I could use?
I was making a drawing as I was going along with taking it apart but I am sure there will be some questions when I will start putting it back together.
PS. Oh and that 5U4 tube...this is the same as the Soviet 5C3S kenotron (the way the power rectifier tube is called in Russian). And I had them out the wazoo. Wish I brought them here. I could use one now.
(This post was last modified: 05-25-2013, 09:15 PM by morzh.)
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Mark Oppat makes some beautiful repros of these dials. I recently bought one of his for my 38-690.
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Yes, Brenda, thanks and I do think with damage this extensive I will have to go to a repro.
After all this will be a major effort to fix this thing, so might as well make it just a tad easier on myself.
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Tom,
getting back to your
>>Oh yes, and with respect to the 6J5, do NOT replace with a 6J5GT or 6J5 metal tubes, as they will not insert into the ones that have a tube shield base.
Not sure what you meant by that, but what I have is one "G" and two "GT/G".
Firs of, there was no metal tubes there whatsoever.
And if anything, "GT/G" goes in the shields I have without any problem; "G" does resist, and there is one tube unshielded and two shielded so I intend to use the same as I have now - 2 "GT/G" will go in the shields and 1 will be unshielded, and that can be either "G" or "GT/G" (not metal, I guess, as it may want the case grounded.
The schematic calls for "5J5G".
I could never figure that out: many of those Philco shields fo over shouldered "G" envelope with quite a bit of squeaking and I was always wondering how they did not crack. Even if you install the shield without damaging a tube, thermally it is not good to have metal against hot glass....though they heat up simultaneously so maybe that's OK, but the insertion is still hard.
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Today I contacted some folks I know from that Ukrainian website, and Peter, the guy who administers the website, said he'd send me 5C3S tube which can go in place of 5U4G.
He also said that their exchange has new Soviet tubes real cheap so he could get some for me for very low price, which I am willing to try. Soviet tubes as I remember were not bad at all. They also have 6S4S which is 6B4, 6S2S (6J5) etc.
In the meantime, here's the tuning cap I just put through my dishwasher.
Just add some lithium grease into the bearings.
(This post was last modified: 05-27-2013, 08:07 PM by morzh.)
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My bad with respect to the 6J5/6J5GT issue. This pertains to the Philco sets that had the shield base that fit very closely around the circumference of the bakelite tube base.
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