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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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7th Aug 2008, 1:17 am | #1 |
Retired Dormant Member
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Pye 15a problem
Hello everyone.
As my plans for a 70s TV have been put on the backburner I have decided to have a shot at fixing my radio. The story is quite short, I bought it for £15 at an auction changed the plug and it worked fine from then on. Then about 7 months later it stopped working, just wouldn't turn on. Now the last time it was turned off I clicked it off at the plug rather than on the set by mistake. Could this have affected anything, I had a look inside and to my un-trained eye can't find anything visibly wrong. Cheers, Anthony |
7th Aug 2008, 8:13 am | #2 |
Hexode
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Re: Pye 15a problem
Hi Anthony !
A quick check : When you power it up, did the dial lamp light ? Ater a certain time does the valve glow ? If not, unplug, and check the fuse. If it's blown replace with SAME rating and redo a test. If it works, bingo ! If not, get a DMM, a soldering iron, the schematics and.... |
7th Aug 2008, 8:50 am | #3 |
Dekatron
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Re: Pye 15a problem
Hi Anthony, a valve set of this age should not be used without some of the capacitors being checked out and probably changed. It's possible it has already done some damage to the transformer or valves.
I am not sure if this is something you would like to try to repair yourself? |
7th Aug 2008, 10:20 am | #4 |
Rest in Peace
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Re: Pye 15a problem
Do the checks as detailed in previous postings. If all looks well, then you will have to delve a little further.
This set has a "mains" energised speaker where the energising field coil for the loudspeaker is in series with the HT line. You might want to check that the energising coil is not O/C. You can easily do this because the field coil plugs into a non-reversible socket on the back apron of the chassis. Remove the field coil plug and measure across the pins. The field coil should measure about 1k ohm This is a handy place to check HT voltage as well. Be VERY careful whilst doing this as the HT will be about 250 volts DC. The voice coil of the loudspeaker plugs into a couple of sockets on the back of the chassis. You can easily check the resistance of the voice coil by removing the two wander plugs from the chassis sockets and use a multimeter. Should be about 2 ohms. That will be a start anyway. Ian. |
7th Aug 2008, 10:28 am | #5 |
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Re: Pye 15a problem
No, there's absolutely nothing wrong with doing this. In fact, some people do this routinely, to save wear and tear on the controls.
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7th Aug 2008, 5:44 pm | #6 |
Octode
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Re: Pye 15a problem
The Wireless World test report from 1946 shows a mains energized loudspeaker, the field being used also to smooth HT ripple (choke). If your valves are lit but there's no sound, it is possible that the field winding could be o/c but there are several other causes of the same fault, such as failure of the rectifier valve or the mains transformer HT secondary. If no valves are lit, the either the transformer is faulty or, more likely, the fuse in the plug has popped, as has been suggested. Another possibility is that the on-off switch at the set has failed. Not uncommon with sets of this age.
Do some basic checks and come back to us. =-Tony |
8th Aug 2008, 1:34 pm | #7 |
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Re: Pye 15a problem
I am pretty sure there is no power getting to it, the tuning light dosen't turn on and the valves don't light or heat up.
It may just be a fuse (even in the plug), but as usuall I have become suddenly busy where my "radio fixing time " was! |
8th Aug 2008, 6:45 pm | #8 |
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Re: Pye 15a problem
Do be very carefull as there are dangerous voltages inside even if it doesn't appear to be working.
If this radio has not had any parts changed it is likely to need some work now. Do you plan to try to repair the set yourself? If you take the chassis out and post a few pictures we can help identify the components that you should check and those you should change before connecting it to the mains again. |
8th Aug 2008, 7:20 pm | #9 | |
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Re: Pye 15a problem
Quote:
I have also noted what looks like a blown fuse, the hunt is now on to find a 2 amp fuse before I do anything else. Thanks for the help, ANthony. |
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8th Aug 2008, 7:42 pm | #10 |
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Re: Pye 15a problem
Don't ever switch things on without at least checking at least fuses, mains wiring and condition. You now have a set which could have anything wrong with it, new faults as well as old. It could also have been dangerous....
Start at the mains plug. Make sure it's wired right and check the fuse. Make sure that the Single Pole On/Off switch is switching live. See if there is continuity across the mains transformer. If there is, take the set apart and check thouroughy. If not, check the wire and switch. I hope the mains transformer hasn't gone. On the secondary side, the rectifier valve is separate, so if this is out as well as the valves, then the mains transformer is at fault unless all the heaters have gone. If the Recky is lit, then the same applies on the other winding. I hope this is simple. This is a short superhet, and the EBL31 is a difficult valve to get. Change C20. I have used Trader Sheet 751. Cheers, Steve P.
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If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...? |
14th Aug 2008, 9:14 pm | #11 |
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Re: Pye 15a problem
Update.
I found a 2 Amp fuse earlier today and after opening the radio up and checking none of the wires were damaged or missing and taking some electrical readings I switched it on. The set warmed up and worked perfectly, this afternoon I turned it on again and whilst turning the volume control the whole set turned off. I traced this to the fuse in the plug, it looked like it was an old one and past it anyway. I fetched my dad and we changed the fuse in the plug and checked the radio again before turning it on again. This time the new 2 amp fuse blew in a spectacular fashion. I would suspect something is shorting on the radio to cause this fuse problem, if anyone has information on the Pye "45a" this radio uses I would be most gratefull to hear from them. I am also on the lookout for a diahgram of the set, does anyone know where to order one online. (Sorry but my question mark key is broken). |
14th Aug 2008, 9:27 pm | #12 |
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Re: Pye 15a problem
I had a Pye not unlike this, which is now with Paul Sherwin (I think).
This made horrible "arcing" noises, and Paul found that the cause was some sleeving on a wire under the chassis had deteriorated, allowing the wire to spark across to the metalwork. It might be worth having a look underneath for this kind of nonsense. Nick. |
14th Aug 2008, 9:30 pm | #13 |
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Re: Pye 15a problem
Up top on the right you can order a circuit diagram and manual.
If the fuse blew in spectacular fashion then do a few checks before you try again. Check the fuseholder, wiring, On-Off switch and voltage adjustments. On the secondary side, check C24. Cheers, Steve P.
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If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...? |
14th Aug 2008, 9:36 pm | #14 |
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Re: Pye 15a problem
Thanks.
I noticed after the seccond fuse blew what I thought was the metal dis-coluring is actually filth, we struggled to get multimeter readings off it so it needs a very good clean. Also, what is the differance between a Pye 15a and 45a, because my radio says 45a on it but looks almost identical to the 15a... Last edited by captain_70s; 14th Aug 2008 at 9:53 pm. Reason: New content added |
15th Aug 2008, 7:18 pm | #15 |
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Re: Pye 15a problem
It's an AC/DC version - Pye 45A.
Things are a little different. It does not have a mains transformer, instead a 'dropper resistor'. The valves are CY31, CBL31, EF39 and CCH35. C29 needs to be checked and replaced with an X2 component. Also check wiring and R20. Cheers, Steve P.
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If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...? |
15th Aug 2008, 7:51 pm | #16 |
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Re: Pye 15a problem
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15th Aug 2008, 8:44 pm | #17 |
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Re: Pye 15a problem
Thanks for the info, I am in the progress of getting service data sheets.
Here are some pics of the set. |
23rd Aug 2008, 10:08 pm | #18 |
Hexode
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Re: Pye 15a problem
The circuit for the 15A can be found in the thin data book that came with some editions of Caxtons Modern Radio and Television, I think the 45A might be there as well. The three volume set goes for peanuts on a well known auction site and occasionally you see them with the data volume as well. My introduction to radio was when my old man gave me a set of these in the late 1950's, I was about ten at the time.
The big problem I have with two of these sets is that the dust iron cores inside the IFT's have broken away from the brass adjuster. Has anyone a good method for reattaching them? OK, in the purest sense of restoration it's a no-no but has anyone tried replacing IFT's with ones from a different set, or even of a different IF frequency Be extremely careful when working on the 45A because the chassis is connected directly to the mains supply Last edited by See_Mos; 23rd Aug 2008 at 10:14 pm. |
24th Aug 2008, 10:55 am | #19 |
Hexode
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Re: Pye 15a problem
My mistake! the 45A chassis is isolated from mains by a .01uf capacitor, still not the safest of sets to work on though.
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24th Aug 2008, 2:27 pm | #20 |
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Re: Pye 15a problem
The correct trader is 859. The mains filter is C28 0.1uF and should be X2 rated. To blow a fuse of 2A the problem isn't going to be very far into the circuit. Apart from C28, I would look at the insulation on the wiring as Steve has suggested. I guess it could be the rectifier.
C2 and C20 are 0.01uF that isolate the pick-up from mains and should be replaced with Y2 types or preferably remove them altogether. As well as not being particularly safe, as soon as you connect it to an earthed device it is going to hum like mad. |