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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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3rd Feb 2019, 3:24 pm | #21 |
Pentode
Join Date: Nov 2018
Location: Burnley, Lancashire, UK.
Posts: 100
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Re: PYE 15A volume
Hi folks sorry for delay been decked with a chest infection for the last week. Hi Alan I have taken the voltage readings as suggested hope I have done this right V1 ECH35 pin 3 600 pin 4 479 pin 6 169, V2 EF 39 pin 3 288 pin 4 483, V3 EBL 31 pin 3 587 pin 6 627 pin 8 044. Should I change the wafer thin mint type wax caps? Once again thank you all for your patience and support. Best regards Ron H.
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3rd Feb 2019, 3:45 pm | #22 |
Hexode
Join Date: Nov 2003
Location: Ossett, West Yorkshire, UK.
Posts: 482
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Re: PYE 15A volume
Voltages are totally wrong! Don't change anything until we sort out what you are doing wrong.
Those silver mica capacitors rarely need changing. |
3rd Feb 2019, 3:57 pm | #23 |
Octode
Join Date: Dec 2018
Location: Llandeilo, West Wales, UK.
Posts: 1,092
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Re: PYE 15A volume
Hi Ron,
Yes way too high to be 'real' figures. First make sure that the 'voltage selector plug' on the mains transformer is in the highest voltage position 240 or 250 volts. Nothing lower. Check you meter is on the highest DC voltage range (1000v ?), clip the negative lead to the metal chassis and measure again please. Start with the voltage on C24 and C25 (the metal can ones) and let us know what you get. Alan
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3rd Feb 2019, 4:02 pm | #24 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
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Re: PYE 15A volume
Include the decimal point...…
Lawrence. |
3rd Feb 2019, 4:44 pm | #25 |
Pentode
Join Date: Nov 2018
Location: Burnley, Lancashire, UK.
Posts: 100
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Re: PYE 15A volume
AH just re checked don't know what happened with first readings obviously had my meter set wrong. Amended readings V1 pin 3. 270 pin 4. 80 pin 6. 56, V2 pin 3. 270 pin 4.. 77 V3 pin 3. 251 pin 6. 270 pin 8. 20. Sorry about that novice inexperience.
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3rd Feb 2019, 5:06 pm | #26 |
Pentode
Join Date: Nov 2018
Location: Burnley, Lancashire, UK.
Posts: 100
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Re: PYE 15A volume
C24 C25 271 & 328 the 271 reading was red spot to earth.
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3rd Feb 2019, 5:32 pm | #27 |
Octode
Join Date: Dec 2018
Location: Llandeilo, West Wales, UK.
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Re: PYE 15A volume
That's much better!
Not a lot wrong for this stage of the game. Have a look at the trader sheet 3rd page at the table of valve voltages. Just a little low on the screen grid (pin 4) measurements of V1 and V2. And the oscillator section (pin 6) of V1. So now do a resistance checks on R4 (39k) ohm and R3 (47k) that See Mos referred to in post no. 16. Those directly influence the low readings you have. Unplug from the mains and let the set rest 5 minute before doing the resistance checks.
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3rd Feb 2019, 6:03 pm | #28 |
Pentode
Join Date: Nov 2018
Location: Burnley, Lancashire, UK.
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Re: PYE 15A volume
Resistors as follows R4 59.2 R3 48. Best regards Ron.
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3rd Feb 2019, 6:27 pm | #29 |
Octode
Join Date: Dec 2018
Location: Llandeilo, West Wales, UK.
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Re: PYE 15A volume
Replace R4 then. Get a 39k ohm, 1 or 2 watt metal film resistor (it will be 350 volt rated). Example only https://uk.farnell.com/welwyn/mfp1-3...ilm/dp/1565384 and ebay might be cheaper.
Can you also measure R11 (150 ohms) and R12 (470 ohms) at some stage? Alan
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3rd Feb 2019, 7:43 pm | #30 |
Pentode
Join Date: Nov 2018
Location: Burnley, Lancashire, UK.
Posts: 100
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Re: PYE 15A volume
Ok Alan resistor ordered. R11 measures 143.8 & R12 336. Cheers Ron H.
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3rd Feb 2019, 9:52 pm | #31 |
Pentode
Join Date: Nov 2018
Location: Burnley, Lancashire, UK.
Posts: 100
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Re: PYE 15A volume
Sorry Allan R 3 should read 108 R.
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4th Feb 2019, 8:48 am | #32 |
Octode
Join Date: Dec 2018
Location: Llandeilo, West Wales, UK.
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Re: PYE 15A volume
Umm, I assume you really mean 108K ohms?
That would help explain the low voltage on V1 pin 6. Yes replace it with a 47K ohm 1 or 2 watt jobbie. Did you replace C19 yet? If not replace it and measure R12 again. If you have replaced C19, please measure R12 again and leave your meter connected for 20 or 30 seconds. If the value increases over time wait and record the highest value you see. If you still read much less than 470 ohms, replace R12. Same as before 1 or 2 watts. Alan
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4th Feb 2019, 12:17 pm | #33 |
Hexode
Join Date: Nov 2003
Location: Ossett, West Yorkshire, UK.
Posts: 482
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Re: PYE 15A volume
R3 should be 47K so Ron's figure of 48 would be about right and the voltage agrees. R4 makes quite a difference, see further down.
The voltages on the one I now have on the desk are now roughly the same as Ron's. I pulled one of mine from the loft. Unfortunately for me it was the one that was stuck in the garage for a few years before being moved to the loft. Not surprisingly it did not work very well. The HT was down and looking at the AZ31 it looked as if one of the heaters was out. A new AZ31 soon fixed that. Reception was still poor and I found R4 measured 56K. A new 39K improved reception quite a bit but not as well as expected. The I.F. transformers in this one are not original. Some time ago I took the worst of my Pye 15A and did some mods to see if alternative I.F's would work so this set has the type with side adjustable cores like the ones used in Sobell 615 and some versions of the army 19 sets. The alignment of the I.F.T's was a bit off and realignment further improved things. Now I can receive a few station at reasonable volume on a couple of yards of aerial wire. Reception isn't brilliant and sensitivity is not very good but about what I would expect for this type of receiver. |
6th Feb 2019, 8:51 pm | #34 |
Pentode
Join Date: Nov 2018
Location: Burnley, Lancashire, UK.
Posts: 100
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Re: PYE 15A volume
Ah thanks See Mos and Allan for all your time and trouble spent on this green newbie I am keen to learn this new hobby. I have ordered the new resistors so will be back with results when they arrive. Best regards Ron H.
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6th Feb 2019, 8:54 pm | #35 |
Pentode
Join Date: Nov 2018
Location: Burnley, Lancashire, UK.
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Re: PYE 15A volume
Ah forgot to ask do resistors go in any way round?
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6th Feb 2019, 9:18 pm | #36 |
Octode
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Location: Llandeilo, West Wales, UK.
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Re: PYE 15A volume
Anyway round you like.
Alan
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6th Feb 2019, 10:27 pm | #37 |
Pentode
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Re: PYE 15A volume
Thanks Allan.
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6th Feb 2019, 11:25 pm | #38 |
Heptode
Join Date: Sep 2007
Location: Brentwood, Essex, UK.
Posts: 687
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Re: PYE 15A volume
I was working on one of these at the weekend and was surprised how well they do work -although they are a short superhet design there is plenty of volume and as sensitive as many 5 valve sets I have got.
So stick at it, well worth fixing up! Steve. |
7th Feb 2019, 3:50 pm | #39 |
Pentode
Join Date: Nov 2018
Location: Burnley, Lancashire, UK.
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Re: PYE 15A volume
Thanks for that Steve. OK progress report I have changed the old Daly 25v 25uf capacitor still same reading on R12 so changed R12 R3 & R4 at this point we seem to be making progress although not a big improvement in volume I was able to tune in one program on short wave then pop the capacitor i replaced for the Daly pope'd I installed it the same polarity as the Daly but the one I used was 22uf 100v and the Daly was 25uf 25 volts have put the Daly back in as a temporary measure but no reception at all now. Best regards Ron H.
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7th Feb 2019, 4:45 pm | #40 |
Octode
Join Date: Dec 2018
Location: Llandeilo, West Wales, UK.
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Re: PYE 15A volume
That is bad luck...
When you say 'no reception', do you mean no sound, no stations or what? I am very surprised a new 22uF 100 volt cap went pop though. The way you describe it working then failing is very much what you get if it is fitted the 'wrong way round'. Can you post pictures of the Daly cap in-situ? Back to voltages again now then. Start with V3 pin 8, you measured 20 volts before. Alan
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