Pye P117 assistance requested - UK Vintage Radio Repair and Restoration Discussion Forum

tommymcg1 · 18th Jan 2019, 1:41 pm

Purchased a Pye P117 radio a few years back as I was really taken with the 1950's design and it had FM reception. Sent the set directly to a well known repair shop as the seller stated that it was not working. The set was received from the repair shop and I was slightly disappointed with the physical size, did not expect it to be so small. Set the radio on a shelf and plugged the length of cable to be used as an aerial into the rear of the set and switched on. The FM reception was good for an old set and it worked well for over a year but not much reception from AM or LW(no matter as I use FM mostly)
The set would work after being switched on for about 20mins then would go very quiet. Tried to retune and sometimes it would come back playing but did not last. Tried moving the volume control back and forward and experience crackling over the speaker. So not sure if the set is going off station tuning? or the volume control requires some sort of attention? Due to all of the capacitors etc have been changed out I am hoping it is a simple repair that I could complete myself rather than sending back to the repair shop.

Any advice would be appreciated

TrevorG3VLF · 18th Jan 2019, 3:24 pm

I looked up this set, it has a live chassis so should be treated with extreme care. Horribly complicated.

I would measure DC voltages when working and when it had gone quiet. Perhaps an electrolytic capacitor has been installed the wrong way round.

Herald1360 · 18th Jan 2019, 3:33 pm

The P117 looks like a fairly straightforward set, but it's a bit "budget" in the PSU dept with no mains isolation transformer for the HT so it has a live chassis needing a bit more care to work on safely and making it difficult to use any grounded test equipment. Battery operated test equipment with no ground connection can still be used.

What test equipment do you have? What is your skill level?

tommymcg1 · 18th Jan 2019, 5:37 pm

Hi Chaps
Thanks for your replies. I am an Instrument Technician working in the North Sea but as you can appreciate valves etc are really old hat compared to the PLC logic I am used to. Test equipment is a very modern Fluke meter but that is it.

Herald1360 · 18th Jan 2019, 11:26 pm

OK.

Modern Fluke meter is good news! Better than nothing by a long way.

Readings might be a bit higher than service sheet ones which will assume a 1,000 opv or 20,000 opv meter depending on how old the set is since the Fluke will likely be a fixed 10Megohm input resistance, so it will load most high impedance circuits less.,

If you think of valves as high voltage n-channel FETs with a few extra non signal ( except in the case of mixers and the like) connections you'll get the idea. Treat a live chassis set with the same respect as the mains side of whatever the PLC is controlling and you won't go far wrong.

Try Trevor's voltage measurement suggestion and see how they compare with any service sheet figures and report back- in as much detail as you like!

18th Jan 2019, 1:41 pm	#1
tommymcg1 Retired Dormant Member Join Date: Jun 2011 Location: Dundee, UK. Posts: 11	Pye P117 assistance requested Purchased a Pye P117 radio a few years back as I was really taken with the 1950's design and it had FM reception. Sent the set directly to a well known repair shop as the seller stated that it was not working. The set was received from the repair shop and I was slightly disappointed with the physical size, did not expect it to be so small. Set the radio on a shelf and plugged the length of cable to be used as an aerial into the rear of the set and switched on. The FM reception was good for an old set and it worked well for over a year but not much reception from AM or LW(no matter as I use FM mostly) The set would work after being switched on for about 20mins then would go very quiet. Tried to retune and sometimes it would come back playing but did not last. Tried moving the volume control back and forward and experience crackling over the speaker. So not sure if the set is going off station tuning? or the volume control requires some sort of attention? Due to all of the capacitors etc have been changed out I am hoping it is a simple repair that I could complete myself rather than sending back to the repair shop. Any advice would be appreciated

18th Jan 2019, 3:24 pm	#2
TrevorG3VLF Rest in Peace Join Date: Apr 2011 Location: Matlock, Derbyshire, UK. Posts: 1,378	Re: Pye P117 assistance requested I looked up this set, it has a live chassis so should be treated with extreme care. Horribly complicated. I would measure DC voltages when working and when it had gone quiet. Perhaps an electrolytic capacitor has been installed the wrong way round.

18th Jan 2019, 3:33 pm	#3
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,536	Re: Pye P117 assistance requested The P117 looks like a fairly straightforward set, but it's a bit "budget" in the PSU dept with no mains isolation transformer for the HT so it has a live chassis needing a bit more care to work on safely and making it difficult to use any grounded test equipment. Battery operated test equipment with no ground connection can still be used. What test equipment do you have? What is your skill level? __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

18th Jan 2019, 5:37 pm	#4
tommymcg1 Retired Dormant Member Join Date: Jun 2011 Location: Dundee, UK. Posts: 11	Re: Pye P117 assistance requested Hi Chaps Thanks for your replies. I am an Instrument Technician working in the North Sea but as you can appreciate valves etc are really old hat compared to the PLC logic I am used to. Test equipment is a very modern Fluke meter but that is it.

18th Jan 2019, 11:26 pm	#5
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,536	Re: Pye P117 assistance requested OK. Modern Fluke meter is good news! Better than nothing by a long way. Readings might be a bit higher than service sheet ones which will assume a 1,000 opv or 20,000 opv meter depending on how old the set is since the Fluke will likely be a fixed 10Megohm input resistance, so it will load most high impedance circuits less., If you think of valves as high voltage n-channel FETs with a few extra non signal ( except in the case of mixers and the like) connections you'll get the idea. Treat a live chassis set with the same respect as the mains side of whatever the PLC is controlling and you won't go far wrong. Try Trevor's voltage measurement suggestion and see how they compare with any service sheet figures and report back- in as much detail as you like! __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O