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Success Stories If you have successfully repaired or restored a piece of equipment, why not write up what you did and post details here. Particularly if it was interesting, unusual or challenging. PLEASE DO NOT POST REQUESTS FOR HELP HERE!

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Old 19th Mar 2020, 10:36 am   #1
MurphyNut
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Default Philco A547B (1948) fixed

I have a mental list of radios Iíd like for my collection and the Philco A547B for some years was on it.
Iíd never seen one in the flesh but from the pictures on the internet it appealed me, it looks solid and purposeful and of course Iím a sucker for anything make of Bakelite.
So it came as a pleasant surprise whist strolling around the big Kempton collectors market I spotted the back of an old valve radio. When I walked around to view it from the front it was the said Philco. I was very surprised at how big this set is; from the images Iíd viewed I imagined it much smaller.
This didnít deter me, I had a good look over it, no damage and nothing missing, we agreed on a price and I proudly carried it back to my car.
Back home, on taking the chassis out from of the cabinet I quickly noticed evidence someone had worked on it, but not much, just an electrolytic capacitor and new mains lead.
On powering it up it did very little, the pilot bulbs came on and a very faint crackle when the wave change switch was selected.
I set about replacing all the wax capacitors and that radiospares electrolytic; this had completely failed and was the wrong value anyway. The smoothing caps were reading spot on so I left them. The wave change contacts were cleaned with Servisol. A few rubber components were replaced and I gave it another go.
I got some sound but not much, just two or three strong stations but very quiet and horribly congested sound.
I was thinking it might be a valve problem, I soon found out most of the valves in this set crop up other sets in my collection. So I found known good ones and tried them in this set. No change at all, so that ruled that theory out!
I wasnít sure what to do next so I contacted and good friend and experienced radio restorer and he pointed me in the direction of troublesome resistor often found in this model.
He was spot on; the 220K resistor was the culprit. (R18 Trader sheet 890) Iíve since spent time looking up people restorations of this model and on more than one occasion this resistor is mentioned.
It now sounds great, very loud and sensitive; I can even pick up stations without an aerial. Cosmetically it was easy getting it looking good, simply a good polish and itís now nice and shiny and almost looks like new.
Nice set, Iíve been listening to all the virus doom and gloom on it most of the day!
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Old 19th Mar 2020, 1:19 pm   #2
ronbryan
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Default Re: Philco A547B (1948) fixed

Clive

Did you mean R14 220k, the triode anode load on Trader Sheet 890, instead of R18, the AF feedback resistor?

Ron
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Old 19th Mar 2020, 1:50 pm   #3
Lloyd 1985
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Default Re: Philco A547B (1948) fixed

Nice work and good tip about said resistor, I’ve got 2 of these sets and neither of them work! I’ve not tried any restoration on them, in fact I was looking to part with one to free up some space.

Looks nice all polished up, maybe I’ll have to give one of mine another chance

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Old 19th Mar 2020, 4:40 pm   #4
MurphyNut
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Default Re: Philco A547B (1948) fixed

Quote:
Originally Posted by ronbryan View Post
Clive

Did you mean R14 220k, the triode anode load on Trader Sheet 890, instead of R18, the AF feedback resistor?

Ron
Thanks Ron, looks like I got that bit wrong.
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Old 30th Mar 2020, 8:26 am   #5
Phil G4SPZ
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Default Re: Philco A547B (1948) fixed

Nice work Clive, that’s a fine-looking set.
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