Posts: 811
Threads: 43
Joined: Dec 2008
City: Chicago, IL
Well it seems a quality 500K audio taper pot with solid metal shaft is a tricky thing to find. Apparently it's a common part in electric guitars and amps. NOS ones are almost non-existent and modern production looks cheap with short knurled shafts. I'll did through my used parts.
Meanwhile, I'm working on a curious issue. The volume cannot be turned all the way down. Even with the grid of the 27 DET AMP tube grounded there is significant volume. Grounding the grid of the 27 1st AF tube completely kills the sound.
I'm thinking there is some crosstalk between leaky caps. Perhaps inside of the #30 capacitor box ?
I'll start by replacing the #23 coupling cap then move on to box #30.
Messages In This Thread
RE: Philco 90 restoration - by Bob Andersen - 09-27-2021, 07:39 PM
Users browsing this thread: 9 Guest(s)
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Recent Posts
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PT-6 finished!!
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Actually the Loctal tube series, with number beginning with "14" are 12.6 volt tubes, at 150 ma, I'm not sure ...Arran — 02:14 AM |
philco predicta
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The model is the holiday without UHF It has no sound and I don't have an oscilloscope or signal generator.cgl18 — 08:51 PM |
Philco model 38 code 121 not receiving signal.
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I will definitely check my lead length and wire dressing. Thanks for the ideas.Stormlord5500 — 08:06 PM |
Philco model 38 code 121 not receiving signal.
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Do make sure that you twist the 3 wires from the chassis to the transformer, and dress away from tubes, especially audio...MrFixr55 — 07:38 PM |
Philco model 38 code 121 not receiving signal.
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The cone unfortunately got damaged when I removed it. The glue that held the cone to the basket was sloppily applied and...Stormlord5500 — 07:12 PM |
Philco model 38 code 121 not receiving signal.
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So what was wrong with the original speaker? Was the cone damaged? Unless it's totally hopeless I would put it aside as ...Arran — 05:31 PM |
My collection presentation
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There is an article on my site that introduces the first portable radios in my collection. I have only provided a link t...Vlad95 — 01:17 PM |
Electrolytic restuffing/internals
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Bridkarl
This specific cap you have is the easiset type to restuff.
I usually cut it at the upper border of the depr...morzh — 11:35 AM |
philco predicta
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Hi CGL18,
First off, welcome to the Philco Phorum. I have not worked on a TV for a while but here are some givens:
...MrFixr55 — 08:22 AM |
Another amp build - here I go again!
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Sweet!
I actually have a Dynaco Mark 4 that I had been running with 6L6s with no mods. Seemed to my 14-year-old head a...MrFixr55 — 12:57 AM |
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