Pye v4 - Page 12 - UK Vintage Radio Repair and Restoration Discussion Forum

Lloyd 1985 · 5th May 2010, 12:20 pm

its starting to look pretty good! funny thing about the cap, I've been having trouble with my TV12, I was using the trader sheet for it and it had some different values in places, and wen I got the propper bush manual, it turned out the values I thought were wrong, were actually modifications. if someone has the correct pye data for this it might be an idea to check it and see if there were any modifications. excellent work so far! I might invest in one of these sets...!

oldticktock · 5th May 2010, 12:29 pm

Hi Lloyd,

I must admit when I changed it to the trader value I thought, bet this is not the thing to do as a more experienced person built this and it's there for a reason. It's easy enough to get at so I can change it if needs be. Just managed to get myself the 1950-1960 Newnes set of books so I will check that when they arrive.

The set looks so much better in the flesh than in photos (much like the PYE LV) I'm in awe of the design and complexity, it's amazing for 1953 you would have expected that more near the end of the decade. One odd thing i'm puzzled by is why the pink glass

Chris

murphyv310 · 5th May 2010, 12:44 pm

Quote:

Originally Posted by oldticktock

C84 this was interesting, it states .01 on the trader but .005 was in circuit!!! I replaced it with the correct trader value.

Results so far.

Chris

C84 appears to be the audio coupling cap (that cap on here) you should not notice a big difference in the audio possibly a small increase of bass using a 0.01uf rather than 0.005uf. My V4 uses a 0.005uf so its either an inaccuracy in the trader sheet or possibly a mod done later on. My V4 is march 53 one of the early ones.

murphyv310 · 5th May 2010, 12:55 pm

Regarding R131 You may have a short circuit cap, a connecting wire that has been shorting or even a collapsed EF80 causing a short.
I would firstly check C101 & C18 then remove R17 and check if the fault clears, if it does the fault is "down wind" of R17 possibly C7, 11, 13 & 14 or the valves. Is R131 the only resistor overheating and what are the voltages on each side of R131?
R131 has been changed in your set did you do it? The RS wirewounds are not original the resistor should be a body tip spot carbon rated at 2/3 watts, if this had been replaced prior to you getting the set it could have been a problem before so I would doubt that a cap is u/s unless its the HT smoother C101

Kevin19 · 5th May 2010, 1:08 pm

Looking good Chris! Just looked in my Newnes and that cap in there is also a 0.01 so same as trader! As for the pink srceen! tinted perspex implosion gaurd they said it was to improve contrast under high ambient lighting conditions.

Hope to see Test Card C by the time I get back from work at 7pm!!! Great stuff

Kevin.

Boom · 5th May 2010, 1:14 pm

The pessimist in me suspects that the pink screen cover could simply have been a bit of subliminal marketing to try and associate the set with colour tv which had yet to appear in the UK.

Chris what does your meter read for Ohms from C101 to chassis?

Dave

PJL · 5th May 2010, 1:18 pm

The other caps that you probably should be loooking at are those on the heater chain, C106-C110. Mind you, I would expect them to have gone pop by now if they were very bad.

Hi Dave...We were taking a cautious approach and sorting the video and other potentially damaging bits, leaving the RF till last.

oldticktock · 5th May 2010, 1:19 pm

Hi Trevor,

The orginal R131 was a medium grey Wire wound not body tip spot. One end of the leg had broken away when I removed it the outer grey coating fell apart. It's value is 470 but I could not tell its Wattage. I put a 470 ceramic in and It lit up and glowed like an ember. I thought Ooops needs a higher wattage, then wired in series a 220R&250R 5Watt tried it again this time it gets VERY! hot and smokes. It measures on both ends 208V, which is odd as one end should be lower surely.

Chris

murphyv310 · 5th May 2010, 1:20 pm

Pye along with other manufacturers used a pink implosion screen to reduce the effect of ambient light reducing the light output of the tube, later VT4's have a clear screen but it's easier to see the wooden frame around the CRT using the clear screen, as they say the choice is yours!!

oldticktock · 5th May 2010, 1:21 pm

Quote:

Originally Posted by boom

chris what does your meter read for ohms from c101 to chassis?

Dave

84.4r

murphyv310 · 5th May 2010, 1:23 pm

Quote:

Originally Posted by oldticktock

Hi Trevor,

The orginal R131 was a medium grey Wire wound not body tip spot. One end of the leg had broken away when I removed it the outer grey coating fell apart. It's value is 470 but I could not tell its Wattage. I put a 470 ceramic in and It lit up and glowed like an ember. I thought Ooops needs a higher wattage, then wired in series a 220R&250R 5Watt tried it again this time it gets VERY! hot and smokes. It measures on both ends 208V, which is odd as one end should be lower surely.

Chris

Hi Chris.
Thats very odd! if the resistor is in circuit and both ends read 208v there cannot be any current drawn, unless you are doing this wrong, meter negative to tv chassis meter positive to one end of R131 first then to the other end.

oldticktock · 5th May 2010, 1:25 pm

Yup that's what i'm doing

murphyv310 · 5th May 2010, 1:28 pm

OK, if you are sure that you are getting 208v DC on either end of the resistor and its in circuit properly connected there is no way it can overheat it wont even get warm, can you please recheck it?

oldticktock · 5th May 2010, 1:32 pm

Here you go pic1 meter testing bottom of R131, pic2 meter results. Pic3 meter testing top of R131, pic4 meter results.

murphyv310 · 5th May 2010, 1:33 pm

OK. And the resistor must be cold! I would say there is something disconnected as there should be a volt drop perhaps 10v so have you left something off?

Station X · 5th May 2010, 1:37 pm

Is the resistor actually connected at both ends? Has it perhaps burned out again? You could try connecting your meter across it which will give a direct reading of volt drop.

oldticktock · 5th May 2010, 1:40 pm

shot of the r131 with bottom leg snipped from wire coming from tag

It was a simple replace, the red wire from c102 went to the top of r131, the pink wire coming from the left went to the top of r131, the bottom of r13 was connected to what was left of the broken leg that was still attached to the 2nd tag point in from the right.

murphyv310 · 5th May 2010, 1:42 pm

The lower side of the resistor goes onto the tag strip and attatches to the 47 ohm carbon resistor. The second tag from the right

Boom · 5th May 2010, 1:44 pm

You can also try measuring if there are any volts at R17 both ends which is what R131 feeds.

Dave

Ah, As Trevor says differently.

oldticktock · 5th May 2010, 1:45 pm

Quote:

Originally Posted by murphyv310

The lower side of the resistor goes onto the tag strip and attatches to the 47 ohm carbon resistor. The second tag from the right

absolutely it does and that resistor hits one end of another resistor a 33k and ends up on pin 8 of a valve (v3)

5th May 2010, 12:20 pm	#221
Lloyd 1985 Nonode Join Date: Jun 2008 Location: Coningsby, Lincolnshire, UK. Posts: 2,819	Re: Pye v4 its starting to look pretty good! funny thing about the cap, I've been having trouble with my TV12, I was using the trader sheet for it and it had some different values in places, and wen I got the propper bush manual, it turned out the values I thought were wrong, were actually modifications. if someone has the correct pye data for this it might be an idea to check it and see if there were any modifications. excellent work so far! I might invest in one of these sets...!

5th May 2010, 12:29 pm	#222
oldticktock Retired Dormant Member Join Date: Nov 2009 Location: Weardale, UK. Posts: 1,981	Re: Pye v4 Hi Lloyd, I must admit when I changed it to the trader value I thought, bet this is not the thing to do as a more experienced person built this and it's there for a reason. It's easy enough to get at so I can change it if needs be. Just managed to get myself the 1950-1960 Newnes set of books so I will check that when they arrive. The set looks so much better in the flesh than in photos (much like the PYE LV) I'm in awe of the design and complexity, it's amazing for 1953 you would have expected that more near the end of the decade. One odd thing i'm puzzled by is why the pink glass Chris

5th May 2010, 12:55 pm	#224
murphyv310 Dekatron Join Date: Sep 2006 Location: Kilmarnock, Ayrshire, UK. Posts: 5,422	Re: Pye v4 Regarding R131 You may have a short circuit cap, a connecting wire that has been shorting or even a collapsed EF80 causing a short. I would firstly check C101 & C18 then remove R17 and check if the fault clears, if it does the fault is "down wind" of R17 possibly C7, 11, 13 & 14 or the valves. Is R131 the only resistor overheating and what are the voltages on each side of R131? R131 has been changed in your set did you do it? The RS wirewounds are not original the resistor should be a body tip spot carbon rated at 2/3 watts, if this had been replaced prior to you getting the set it could have been a problem before so I would doubt that a cap is u/s unless its the HT smoother C101 __________________ Cheers, Trevor. MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member Last edited by murphyv310; 5th May 2010 at 1:10 pm. Reason: add more info

5th May 2010, 1:08 pm	#225
Kevin19 Tetrode Join Date: May 2009 Location: Cogenhoe, Northamptonshire, UK. Posts: 90	Re: Pye v4 Looking good Chris! Just looked in my Newnes and that cap in there is also a 0.01 so same as trader! As for the pink srceen! tinted perspex implosion gaurd they said it was to improve contrast under high ambient lighting conditions. Hope to see Test Card C by the time I get back from work at 7pm!!! Great stuff Kevin.

5th May 2010, 1:14 pm	#226
Boom Retired Dormant Member Join Date: Jan 2007 Location: Westbury, Wiltshire, UK. Posts: 2,451	Re: Pye v4 The pessimist in me suspects that the pink screen cover could simply have been a bit of subliminal marketing to try and associate the set with colour tv which had yet to appear in the UK. Chris what does your meter read for Ohms from C101 to chassis? Dave

5th May 2010, 1:18 pm	#227
PJL Dekatron Join Date: Sep 2005 Location: Seaford, East Sussex, UK. Posts: 5,997	Re: Pye v4 The other caps that you probably should be loooking at are those on the heater chain, C106-C110. Mind you, I would expect them to have gone pop by now if they were very bad. Hi Dave...We were taking a cautious approach and sorting the video and other potentially damaging bits, leaving the RF till last.

5th May 2010, 1:19 pm	#228
oldticktock Retired Dormant Member Join Date: Nov 2009 Location: Weardale, UK. Posts: 1,981	Re: Pye v4 Hi Trevor, The orginal R131 was a medium grey Wire wound not body tip spot. One end of the leg had broken away when I removed it the outer grey coating fell apart. It's value is 470 but I could not tell its Wattage. I put a 470 ceramic in and It lit up and glowed like an ember. I thought Ooops needs a higher wattage, then wired in series a 220R&250R 5Watt tried it again this time it gets VERY! hot and smokes. It measures on both ends 208V, which is odd as one end should be lower surely. Chris

5th May 2010, 1:20 pm	#229
murphyv310 Dekatron Join Date: Sep 2006 Location: Kilmarnock, Ayrshire, UK. Posts: 5,422	Re: Pye v4 Pye along with other manufacturers used a pink implosion screen to reduce the effect of ambient light reducing the light output of the tube, later VT4's have a clear screen but it's easier to see the wooden frame around the CRT using the clear screen, as they say the choice is yours!! __________________ Cheers, Trevor. MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member

5th May 2010, 1:25 pm	#232
oldticktock Retired Dormant Member Join Date: Nov 2009 Location: Weardale, UK. Posts: 1,981	Re: Pye v4 Yup that's what i'm doing

5th May 2010, 1:28 pm	#233
murphyv310 Dekatron Join Date: Sep 2006 Location: Kilmarnock, Ayrshire, UK. Posts: 5,422	Re: Pye v4 OK, if you are sure that you are getting 208v DC on either end of the resistor and its in circuit properly connected there is no way it can overheat it wont even get warm, can you please recheck it? __________________ Cheers, Trevor. MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member

5th May 2010, 1:32 pm	#234
oldticktock Retired Dormant Member Join Date: Nov 2009 Location: Weardale, UK. Posts: 1,981	Re: Pye v4 Here you go pic1 meter testing bottom of R131, pic2 meter results. Pic3 meter testing top of R131, pic4 meter results. Attached Thumbnails

5th May 2010, 1:33 pm	#235
murphyv310 Dekatron Join Date: Sep 2006 Location: Kilmarnock, Ayrshire, UK. Posts: 5,422	Re: Pye v4 OK. And the resistor must be cold! I would say there is something disconnected as there should be a volt drop perhaps 10v so have you left something off? __________________ Cheers, Trevor. MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member

5th May 2010, 1:37 pm	#236
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Pye v4 Is the resistor actually connected at both ends? Has it perhaps burned out again? You could try connecting your meter across it which will give a direct reading of volt drop. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

5th May 2010, 1:40 pm	#237
oldticktock Retired Dormant Member Join Date: Nov 2009 Location: Weardale, UK. Posts: 1,981	Re: Pye v4 shot of the r131 with bottom leg snipped from wire coming from tag It was a simple replace, the red wire from c102 went to the top of r131, the pink wire coming from the left went to the top of r131, the bottom of r13 was connected to what was left of the broken leg that was still attached to the 2nd tag point in from the right. Attached Thumbnails

5th May 2010, 1:42 pm	#238
murphyv310 Dekatron Join Date: Sep 2006 Location: Kilmarnock, Ayrshire, UK. Posts: 5,422	Re: Pye v4 The lower side of the resistor goes onto the tag strip and attatches to the 47 ohm carbon resistor. The second tag from the right __________________ Cheers, Trevor. MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member

5th May 2010, 1:44 pm	#239
Boom Retired Dormant Member Join Date: Jan 2007 Location: Westbury, Wiltshire, UK. Posts: 2,451	Re: Pye v4 You can also try measuring if there are any volts at R17 both ends which is what R131 feeds. Dave Ah, As Trevor says differently.