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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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16th May 2022, 3:48 pm | #1 |
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Philips 22GF813.
Does anyone have a circuit diagram for this record player?
The one I've been asked to repair has a negative earth with a couple of TO220 transistors as the output pair. The deck is a version of the UA15 and the motor acts as a transformer. Something somewhere doesn't feel right. |
16th May 2022, 5:09 pm | #2 |
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Re: 22gf813
Are you sure it's a 22GF813? I think at least some of them were labeled 13GF813, which seems to produce some search results.
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16th May 2022, 5:09 pm | #3 |
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Re: 22gf813
This early Philips transistor player from 1965 usually has the special order Philips (badged and chromed) version of the BSR UA25 with their own GP plug in head or just a bog standard UA25. Not seen one with the earlier UA15 deck. Is the motor tap giving you the correct voltage? That UA15, might just be a replacement deck.
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16th May 2022, 5:48 pm | #4 |
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Re: Philips 22GF813.
1965 is very early for TO220 transistors.
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16th May 2022, 7:53 pm | #5 |
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Re: Philips 22GF813.
Looks like it was made for the UK market: http://www.grammofoon.com/frameset.h...m&ContentFrame
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16th May 2022, 7:59 pm | #6 |
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Re: Philips 22GF813.
It was probably made in the UK.
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16th May 2022, 8:38 pm | #7 |
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Re: Philips 22GF813.
I found one of these in a skip about 30 years ago. It worked but was an unremarkable performer aimed at the teens market, so I stripped it for spares, so it may be that I have some bits from it still lying around. I'm sure the output transistors weren't TO-220 originally, probably AD161/162 or even AC128/176
Here's an ad from the NME in 1967... Last edited by Nickthedentist; 16th May 2022 at 9:02 pm. |
16th May 2022, 8:49 pm | #8 |
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Re: Philips 22GF813.
The 13GF813 looks very similar: https://www.service-data.com/product...94/5693/m20394
Or the Stella ST8003: https://www.service-data.com/section.php/7744/1/st8003 Date seems to be 1967-8ish. These have a +24V supply derived from the UA25's motor overwind, and the OP transistors are U17223/4 (no, I've not heard of them either!) developing 2W into a 25R LS. https://www.radiomuseum.org/tubes/tube_u17223.html https://www.radiomuseum.org/tubes/tube_u17224.html Yours sounds like someone's done something fairly radical to it! Last edited by Nickthedentist; 16th May 2022 at 9:01 pm. |
16th May 2022, 10:25 pm | #9 |
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Re: Philips 22GF813.
So it appears that the transistors U17223 and U17224 are germanium types probably AC141/AC142 equivalents, I think I'll probably fit these and see what happens. unless of course anyone can advise otherwise.
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16th May 2022, 11:11 pm | #10 |
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Re: Philips 22GF813.
What are the fault symptoms, Michael?
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17th May 2022, 8:11 am | #11 |
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Re: Philips 22GF813.
The sound cuts out after around 1/2 hour of playing. Its distorted for the first few seconds. i do need to do more checks on it.
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28th May 2022, 9:14 am | #12 |
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Re: Philips 22GF813.
An update:
I fitted the AC141/142 and fitted TO5 heatsinks to them, but after a few seconds, they get hot and the amplifier stops working. If you freeze them then it works for a few more seconds. Looking at the service manual it would appear that that was what was fitted originally. They probably need better heatsinking but there is no where to fit a larger heatsink. I could extend the transistor leads and fit them to the small metal panel, or I could try a different set of transistors like AC187/188. Or I could reduce the current going through them, but I dont really know how. There is no information whatsoever on the original transistors. Can anyone suggest where I go from here? |
28th May 2022, 9:17 am | #13 |
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Re: Philips 22GF813.
Are there any pots for biasing adjustment, Michael? If not there could be some resistor altered in value in the base circuit.
I assume the supply voltage in in spec from the rectifier
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28th May 2022, 9:50 am | #14 |
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Re: Philips 22GF813.
There are no presets whatsoever. The voltage from the rectifier is correct but drops right down when the transistors get hot.
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28th May 2022, 11:31 am | #15 |
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Re: Philips 22GF813.
I recall working on a Philips record player for a friend while working at Stirling University.
Some of the transistors in the amp were short and while I have no recollection of the model or transistors I do recall that they were manufactured by SGS, and Towers books had no mention of them at all. At that time I had a friend that worked in the SGS factory in Falkirk so I rang him for advice, he had also never heard of them but got back to me later in the day to say that the numbers corresponded to rejects of certain transistors, the proper ones were fitted and a repair was successful. Always stuck in my mind that any manufacturer would use rejects, but there you go. |
28th May 2022, 2:32 pm | #16 |
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Re: Philips 22GF813.
If this is a paid repair, and in the absence of info and the possibility someone has been modifying the cct, you may make it viable by using one of those cheap chinese amp modules with a 1 meg resistor on the input, rather than chase your tail on this.
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29th May 2022, 12:33 am | #17 |
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Re: Philips 22GF813.
I'd prefer to fix the original, thank you.
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29th May 2022, 9:18 am | #18 |
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Re: Philips 22GF813.
Thinking about it a bit more, the amp is a negative earth so unlikely to be germanium transistors, so I will try again with silicon TO5 types. Can anyone recommend suitable ones.
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2nd Jun 2022, 7:45 pm | #19 |
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Re: Philips 22GF813.
An update: I replaced T4 and T5 with BFX39 and BFY50 and it is working correctly.
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2nd Jun 2022, 10:12 pm | #20 |
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Re: Philips 22GF813.
Well done, I’m impressed
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