11th Jun 2021, 1:28 pm | #1 |
Heptode
Join Date: Jun 2018
Location: Carmarthenshire, Wales, UK.
Posts: 569
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Pye p43
I have the above radio. But there is no sound what so ever. Not a crackle when changing frequency or use of volume nothing but a very low hum. I have changed valves all except EZ40 which I did not have all valves are glowing OK. Could it be the output transformer to the speaker. I have also tried another speaker. How do I test the speaker transformer please.
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11th Jun 2021, 3:46 pm | #2 |
Nonode
Join Date: Jun 2013
Location: Surbiton, SW London, UK.
Posts: 2,801
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Re: Pye p43
Download ; Newnes Radio Repair Questions and Answers from this list;
https://www.vintage-radio.info/books Answers are on p.64 of the pdf. The book is well worth studying. |
12th Jun 2021, 6:32 pm | #3 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,289
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Re: Pye p43
With a totally dead radio the best thing to do is check voltage readings and compare them with the service sheet. Start with the rectifier and then work backwards from the output stage towards the aerial. You'll soon see whether the primary winding of the output transformer is any good.
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
13th Jun 2021, 9:24 pm | #4 |
Hexode
Join Date: Feb 2008
Location: Wrexham, North Wales, UK.
Posts: 466
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Re: Pye p43
Start by getting the Trader sheet for this set (link at the top right hand corner of this page).
Unless you have one, get a multimeter which reads ohms and volts at least (£5 on ebay). Identify tags c, d and e of the output transformer and check them with the ohms range of your meter. d to c should be of the order of 15 ohms and d to e around 400 ohms. This is much the most likely source of faults. If these figures are around the right level, switch your meter to a high DC volts range (250V or greater), switch the set on and measure the voltage between each of tags c, d and e and the chassis. WITH CARE!!! You should be getting readings around 200V. If any of these is much lower than this, suspect the reservoir/smoothing capacitors. If the voltage is at or near zero, the likeliest culprit is the mains transformer secondary. It's unlikely to be a valve problem, these little chaps are very robust. |