Pye radio chassis - UK Vintage Radio Repair and Restoration Discussion Forum

Neil Purling · 9th Dec 2009, 11:10 am

I am thinking of buying a Pye 45A radio chassis.
I was surprised to find it is a AC/DC model as there seems to be a square hole that could have been for a transformer mounting.
I don't know what period this chassis was exactly. From searching this forum it seems late forties because there's no 'minature' valves yet and there is evidence of War Surplus American Sprague capacitors & ex WD paxolin valve holders in the example the member posted about.

It looks like the same chassis was possibly used for another model that was AC only.

Steve_P · 9th Dec 2009, 11:15 am

Yes, there was the 15A and a 45A. The 45A is the AC'DC version and 15A is the DC one.

Cheers,

Steve P.

AlanBeckett · 9th Dec 2009, 11:40 am

There's also a battery version of the 15A, the 65A.
Alan

paulsherwin · 9th Dec 2009, 11:58 am

Pye made AC and AC/DC variants of many of their sets and did indeed use the same chassis hardware. Many manufacturers did this sometimes but Pye were particularly keen on it.

Paul

Neil Purling · 9th Dec 2009, 1:19 pm

What was the HT line voltage for the 15A?
I haven't got the Trader sheet to hand. Is there two heater windings, so the rectifier has its own?

Nickthedentist · 9th Dec 2009, 1:40 pm

Hi Neil,

The 15A's HT seems to be 275V.

Yes, 3 secondary windings; HT, rectifier heater, other heaters.

Nick.

Neil Purling · 9th Dec 2009, 1:44 pm

Is the 15A a unusual model?
It is by no means certain I'll buy the chassis.
What's the rectifier of the 15A? If I did I thought of getting the proper 15A HT transformer.
Of course, I will ask in the proper place if that is what I decide to do.

Steve_P · 9th Dec 2009, 2:51 pm

On the 15A it's an AZ31. It's a CY31 on the 45A.

Cheers,

Steve P.

captain_70s · 9th Dec 2009, 10:50 pm

Quote:

Originally Posted by Neil Purling

I don't know what period this chassis was exactly. From searching this forum it seems late forties because there's no 'minature' valves yet and there is evidence of War Surplus American Sprague capacitors & ex WD paxolin valve holders in the example the member posted about.

I belive the 15A was introduced in 1945 and the 45A in 1946 although I am unsure if this is exactly correct. Its been a while since I had the chance to look at mine or indeed read up on it.

Neil Purling · 25th Dec 2009, 2:05 pm

In the Pye 15A & 45A:
How was the mains cord fitted?
In the chassis I have got there is no evidence of a cord grip.
What would you reccomend that will safely hold & retain some 5 amp round 3-core?

Neil Purling · 29th Dec 2009, 11:21 am

I have started on the renovation by changing some caps, till I ran out of capacitors & solder.
The capacitors come from the Ukraine & the solder is by post too, because it was the only way to buy the proper 60/40 Ersin Multicore.
If there is someone reading this with a Pye 15A or 45A can you comment on the tone switch positions?
As the taste of the past was for 'mellow' I wonder if the radio would thus sound like it was playing on the other side of a door in anything other than the 'Bright' position?
What I have is a orphan chassis with some original bits missing, so originality has already gone.

dr peppers · 5th Jan 2010, 12:32 am

I have a pye p43a, I dont know if there is any similarity, mine has the square cutout with the transfromer fitted, so its ac only.
Its only a 4 valve set, the audio is not so good, I suspect 'that' cap, a dodgy output tube or an offcentre speaker cone.
I have trouble with solder too, tin/lead stuff seems to be hard to obtain now, its all this lead free stuff which is real hard to work with.
You can buy cable retaining clips from maplins, they are a bit severe, the cable is bent in a tight 'u' and placed in the clip which fits into a odd-round hole in the chassis, or a round hole when I've fitted them.

dr peppers · 5th Jan 2010, 12:33 am

Oops bad edit

Neil Purling · 7th Feb 2010, 7:29 am

The current state of play on my Pye 15 A chassis is that I have added a home brew PSU arrangement, not the original Pye mains transformer. I have approx 260V HT, and all the heaters are working.The radio is still silent, apart from a very low hum. I have to say there is not much of a buzz when I touch the top cap of the EBL31, (which is a new valve). I get a crackle when I touch a screwdriver to the top cap of the EF39 IF amplifier.
There is no hiss at all from the speaker. I have not yet plugged a aerial into the set. at the time I was making this initial investigation I had a rugby match playing on my Ekco I didn't want to miss.
HT is present on the anode of the EBL31.
I am not sure of the mixer/osc. I have already found the resistor feeding the screen grid of the ECH35 to measure 56K when it should be 39K +/- 10%.
I expect to have to replace several out of spec resistors. This is no surprise.

If anyone has a Pye 15A or 45A can they tell me the switch positions of the tone switch and the band switch? At present I have no idea what band is selected.

Neil Purling · 8th Feb 2010, 12:12 pm

Some more information, in the hope that someone will be motivated enough into entering a response.
The only sound out of the speaker is a sort of pop-pop, occuring about twice a second, the pulse being visible if I stick my scope probe on the volume control.
The local oscillator is apparently running, because there is a signal on the anode of the ECH35. it is also there when I apply the probe to the top cap conn (g1) of the EF39 IF amp, so it gets that far.
No response when I applied my signal generator. I did 'scope the o/p of the sig gen to make sure that was working. I should have got a 1Kz tone in the speaker.

Can you offer me any more advice, please?

Herald1360 · 8th Feb 2010, 1:33 pm

Start at the back? Stick some audio onto the volume control.... try some modulated IF from the sig gen at the detector / IF input.

Use another rx to see if LO is running at correct offset from signal frequency.

Possibly problem(s) with IFT's?

Pop-pop sounds like motorboating- poor HT decoupling capacitors perhaps, though with only a single stage of audio there's not much gain to get upset.

Have fun!

Chris

Steve_P · 8th Feb 2010, 4:25 pm

Try working back with a sig generator (IF will be the same on all bands) and see where you lose it. Measure valve voltages and post them here.

Cheers,

Steve P.

Neil Purling · 8th Feb 2010, 10:32 pm

Would it work if I fed a signal from a cassette tape recorder to the top cap (g1) of the EBL31, or is the impedance totally wrong? I get no response from the speaker.
How else can I verify the AF stage is working?

The EBL1 and EBL31 are one and the same, except for the different base?
The o/p vale is not a Mullard EBL31. It is of Continental origin & what I heard was that it was a EBL1, but the Ct8 base was removed & a IO one fitted. The TC connection is larger diameter than the original.

Neil Purling · 9th Feb 2010, 10:28 pm

Spot the pillock time: I took a close look at what was supposed to be a EF39 sans metalisation. Marked 1005, IMXA on the glass & nowt else. I think this was a EL32/VT52.

I had a rake about and came up with a 6K7G and bunged that in.
A feint 1Kz tone when I injected a signal into the ECH35 top cap at about 460-500Khz. I am not happy about the signal generator.

I have replaced some out of tolerance resistors and all the waxies of course.
I have squirted all the valve pin holes with Servisol 10. I am not sure where to go next, but a local Forum member has generously offered assistance.
With a better sig gen maybe we can track down the source of the problem?
I need to track a signal through from RF to the AF end. On the way we can see if there are any bad contacts on the various switches & valve bases.

Neil Purling · 13th Feb 2010, 11:20 pm

I have had more of a poke around the EBL31, replacing the cathode bias resistors.
I have now got music, only it is still not blasting out at full volume, but it is there.
I found something calling itself Radio Free Asia on SW broadcasting to Tibet & RTE1 on LW with a wire aerial.
However, on local signals the sound is distorted like there is no AGC action & it sounds muffled at every step of the tone switch.
At least I have got music

9th Dec 2009, 11:10 am	#1
Neil Purling Nonode Join Date: Jul 2005 Location: Hull, East Yorkshire, UK. Posts: 2,087	Pye radio chassis I am thinking of buying a Pye 45A radio chassis. I was surprised to find it is a AC/DC model as there seems to be a square hole that could have been for a transformer mounting. I don't know what period this chassis was exactly. From searching this forum it seems late forties because there's no 'minature' valves yet and there is evidence of War Surplus American Sprague capacitors & ex WD paxolin valve holders in the example the member posted about. It looks like the same chassis was possibly used for another model that was AC only. Last edited by Station X; 9th Dec 2009 at 11:38 am. Reason: To comply with forum rules.

9th Dec 2009, 11:15 am	#2
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Pye radio chassis Yes, there was the 15A and a 45A. The 45A is the AC'DC version and 15A is the DC one. Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

9th Dec 2009, 11:40 am	#3
AlanBeckett Rest in Peace Join Date: Dec 2008 Location: Burton upon Trent, East Staffordshire, UK. Posts: 1,686	Re: Pye radio chassis There's also a battery version of the 15A, the 65A. Alan

9th Dec 2009, 11:58 am	#4
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,947	Re: Pye radio chassis Pye made AC and AC/DC variants of many of their sets and did indeed use the same chassis hardware. Many manufacturers did this sometimes but Pye were particularly keen on it. Paul

9th Dec 2009, 1:19 pm	#5
Neil Purling Nonode Join Date: Jul 2005 Location: Hull, East Yorkshire, UK. Posts: 2,087	Re: Pye radio chassis What was the HT line voltage for the 15A? I haven't got the Trader sheet to hand. Is there two heater windings, so the rectifier has its own?

9th Dec 2009, 1:40 pm	#6
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,846	Re: Pye radio chassis Hi Neil, The 15A's HT seems to be 275V. Yes, 3 secondary windings; HT, rectifier heater, other heaters. Nick.

9th Dec 2009, 1:44 pm	#7
Neil Purling Nonode Join Date: Jul 2005 Location: Hull, East Yorkshire, UK. Posts: 2,087	Re: Pye radio chassis Is the 15A a unusual model? It is by no means certain I'll buy the chassis. What's the rectifier of the 15A? If I did I thought of getting the proper 15A HT transformer. Of course, I will ask in the proper place if that is what I decide to do.

9th Dec 2009, 2:51 pm	#8
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Pye radio chassis On the 15A it's an AZ31. It's a CY31 on the 45A. Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

25th Dec 2009, 2:05 pm	#10
Neil Purling Nonode Join Date: Jul 2005 Location: Hull, East Yorkshire, UK. Posts: 2,087	Re: Pye radio chassis In the Pye 15A & 45A: How was the mains cord fitted? In the chassis I have got there is no evidence of a cord grip. What would you reccomend that will safely hold & retain some 5 amp round 3-core?

29th Dec 2009, 11:21 am	#11
Neil Purling Nonode Join Date: Jul 2005 Location: Hull, East Yorkshire, UK. Posts: 2,087	Re: Pye radio chassis I have started on the renovation by changing some caps, till I ran out of capacitors & solder. The capacitors come from the Ukraine & the solder is by post too, because it was the only way to buy the proper 60/40 Ersin Multicore. If there is someone reading this with a Pye 15A or 45A can you comment on the tone switch positions? As the taste of the past was for 'mellow' I wonder if the radio would thus sound like it was playing on the other side of a door in anything other than the 'Bright' position? What I have is a orphan chassis with some original bits missing, so originality has already gone.

5th Jan 2010, 12:32 am	#12
dr peppers Retired Dormant Member Join Date: Nov 2009 Location: Lancashire, UK. Posts: 67	Re: Pye radio chassis I have a pye p43a, I dont know if there is any similarity, mine has the square cutout with the transfromer fitted, so its ac only. Its only a 4 valve set, the audio is not so good, I suspect 'that' cap, a dodgy output tube or an offcentre speaker cone. I have trouble with solder too, tin/lead stuff seems to be hard to obtain now, its all this lead free stuff which is real hard to work with. You can buy cable retaining clips from maplins, they are a bit severe, the cable is bent in a tight 'u' and placed in the clip which fits into a odd-round hole in the chassis, or a round hole when I've fitted them. Last edited by dr peppers; 5th Jan 2010 at 12:38 am.

5th Jan 2010, 12:33 am	#13
dr peppers Retired Dormant Member Join Date: Nov 2009 Location: Lancashire, UK. Posts: 67	Re: Pye radio chassis Oops bad edit

7th Feb 2010, 7:29 am	#14
Neil Purling Nonode Join Date: Jul 2005 Location: Hull, East Yorkshire, UK. Posts: 2,087	Re: Pye radio chassis The current state of play on my Pye 15 A chassis is that I have added a home brew PSU arrangement, not the original Pye mains transformer. I have approx 260V HT, and all the heaters are working.The radio is still silent, apart from a very low hum. I have to say there is not much of a buzz when I touch the top cap of the EBL31, (which is a new valve). I get a crackle when I touch a screwdriver to the top cap of the EF39 IF amplifier. There is no hiss at all from the speaker. I have not yet plugged a aerial into the set. at the time I was making this initial investigation I had a rugby match playing on my Ekco I didn't want to miss. HT is present on the anode of the EBL31. I am not sure of the mixer/osc. I have already found the resistor feeding the screen grid of the ECH35 to measure 56K when it should be 39K +/- 10%. I expect to have to replace several out of spec resistors. This is no surprise. If anyone has a Pye 15A or 45A can they tell me the switch positions of the tone switch and the band switch? At present I have no idea what band is selected.

8th Feb 2010, 12:12 pm	#15
Neil Purling Nonode Join Date: Jul 2005 Location: Hull, East Yorkshire, UK. Posts: 2,087	Re: Pye radio chassis Some more information, in the hope that someone will be motivated enough into entering a response. The only sound out of the speaker is a sort of pop-pop, occuring about twice a second, the pulse being visible if I stick my scope probe on the volume control. The local oscillator is apparently running, because there is a signal on the anode of the ECH35. it is also there when I apply the probe to the top cap conn (g1) of the EF39 IF amp, so it gets that far. No response when I applied my signal generator. I did 'scope the o/p of the sig gen to make sure that was working. I should have got a 1Kz tone in the speaker. Can you offer me any more advice, please?

8th Feb 2010, 1:33 pm	#16
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,535	Re: Pye radio chassis Start at the back? Stick some audio onto the volume control.... try some modulated IF from the sig gen at the detector / IF input. Use another rx to see if LO is running at correct offset from signal frequency. Possibly problem(s) with IFT's? Pop-pop sounds like motorboating- poor HT decoupling capacitors perhaps, though with only a single stage of audio there's not much gain to get upset. Have fun! Chris __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

8th Feb 2010, 4:25 pm	#17
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Pye radio chassis Try working back with a sig generator (IF will be the same on all bands) and see where you lose it. Measure valve voltages and post them here. Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

8th Feb 2010, 10:32 pm	#18
Neil Purling Nonode Join Date: Jul 2005 Location: Hull, East Yorkshire, UK. Posts: 2,087	Re: Pye radio chassis Would it work if I fed a signal from a cassette tape recorder to the top cap (g1) of the EBL31, or is the impedance totally wrong? I get no response from the speaker. How else can I verify the AF stage is working? The EBL1 and EBL31 are one and the same, except for the different base? The o/p vale is not a Mullard EBL31. It is of Continental origin & what I heard was that it was a EBL1, but the Ct8 base was removed & a IO one fitted. The TC connection is larger diameter than the original.

9th Feb 2010, 10:28 pm	#19
Neil Purling Nonode Join Date: Jul 2005 Location: Hull, East Yorkshire, UK. Posts: 2,087	Re: Pye radio chassis Spot the pillock time: I took a close look at what was supposed to be a EF39 sans metalisation. Marked 1005, IMXA on the glass & nowt else. I think this was a EL32/VT52. I had a rake about and came up with a 6K7G and bunged that in. A feint 1Kz tone when I injected a signal into the ECH35 top cap at about 460-500Khz. I am not happy about the signal generator. I have replaced some out of tolerance resistors and all the waxies of course. I have squirted all the valve pin holes with Servisol 10. I am not sure where to go next, but a local Forum member has generously offered assistance. With a better sig gen maybe we can track down the source of the problem? I need to track a signal through from RF to the AF end. On the way we can see if there are any bad contacts on the various switches & valve bases.

13th Feb 2010, 11:20 pm	#20
Neil Purling Nonode Join Date: Jul 2005 Location: Hull, East Yorkshire, UK. Posts: 2,087	Re: Pye radio chassis I have had more of a poke around the EBL31, replacing the cathode bias resistors. I have now got music, only it is still not blasting out at full volume, but it is there. I found something calling itself Radio Free Asia on SW broadcasting to Tibet & RTE1 on LW with a wire aerial. However, on local signals the sound is distorted like there is no AGC action & it sounds muffled at every step of the tone switch. At least I have got music