Pye P35 table radio.

[paoloradio]

Hi everibody,
I'm Paolo, from Roma.
I have the Pye p.35 with the impedance/output tranformer burned out.
There's someone who can tell me something about this transformer or someone who can tell me where I can find another one like it?
In Italy we have not British radios.
Can you help me?
Thank you!!
If someone needs to know something about italian radios,write me.
I have 2500 schematics from 1933 to 1957.

[Steve_P]

Well the resistance is 400 Ohms Primary / 0.4 Ohms Secondary. Don't have the number of turns to hand, but there are the inductances.

But why did it fail. Check the area fully : V4 is an EL33. I'd also check R17, R18, C34 and especially C32.

Cheers,

Steve P

[paulsherwin]

You should be able to substitute a range of output transformers. Anything designed to match a valve to a 3 or 4 ohm speaker should be OK. A transformer from another EL33 set would be ideal but most output transformers will work - EL84, 6V6 etc. The impedence won't be exactly correct but this isn't critical.

Paul

[XTC]

The IO EL33 is very similar to the B8A EL41 which was a very common O/P valve in AC only sets in the UK, and I suspect, across Europe. You should be able to track down a scrap set using an EL41 for very little.

Myself, I'd be more worried if I had a set using an EL33 with a good O.P transformer and a dead EL33.

Pete.

[peter_sol]

Hi. The impedance should be 7K to possibly 3 Ohms but anything similar should work without too much of a problem

Regards
Peter.

[yestertech]

Hi Paulo - The transformer for the P35 has a "tap" to supply the power to the rest of the set. Is this still working ? If not, and this is the only part of the transformer burnt out, you may be able to substitute a resistor for the burnt out section. Otherwise of course, you will need to replace the transformer.
To check :

1. Do you have volts on Pin 3 of EL33 ?
2. DO you have volts on Pin 4 of EL33 ?


Meantime I'll see if I've anything suitable

Andy

[paoloradio]

Hi Andy,
thanks for the answer.
When i try to connect the transformer to high voltage, I read zero volts and the rectifier plates became red.(I hear a very loud scratch and I see a long sparkle)
If I disconnect the transformer from high voltage, I read 300 volts(more or less) on the first section of the filtering condenser(32+32 mfd).
With the trasformer all disconnected but the high voltage wires, I read 300 volts on every point of the transf.
I think it's gone.
I will try to use the resistor.
Thanks again.
All the best.
Paolo.

[paoloradio]

Thank you, Paul.
The problem is in the impedance section, I think.
If I disconnect HV from the transformer,I read 300 volts more or less.
If I reconnect the HV wires to the transf. I read zero volts and the rect. plates became red.
I read 300 V on every point of the transf.

[paoloradio]

Thanks to everybody for the informations.
I hope to be a good and useful member of this forum.
I'm sorry for my non-perfect english and I am so grateful to everybody for the efforts you are making to understand me.
I'll try again with other impedances, but I think that the transformer is gone.
I'll write again to communicate you the results.
Thank you very much!!!
Paolo.

[yestertech]

Paolo, your non-perfect English is just fine !
It sounds as if your transformer has a primary to secondary short.
This would cause the symptoms you describe.
As it seems quite severe, you will probably be able to measure it with a meter set to ""ohms". If you connnect the transformer into circuit with no power applied and measure from EL33 pin 3 to chassis, you will probably get a low resistance reading ( 500 ohms or so )
If you do, then the transfomer will definitely need replacing.

Andy

[paoloradio]

Hello everybody,
EUREKA!!!
The Pye is talking again!!!
The problem was the transformer/impedance, rewinded by an old and very experienced man.
There is another little problem with the volume control that doesn't go to zero and in the minimum position it works like a tone control with a low frequencies cutting.
I have a question for everybody:do you know someone that can sell the complete valves series for the p.35?
Here, in Italy, we don't have valves of that kind.
We have "red"valves with different sockets like ebc3,el3n,ech3,az1,ecc.but not red valves with octal sockets.
Thanks to everybody.
All the best.
Paolo.

[Ed_Dinning]

Hi Paolo, these are quite common valves here, I can probably find you some used ECH35, EF39 and EBC33's. The EL33 is not uncommon and has some equivalents as does the AZ31.

Best regards, Ed

[paulsherwin]

Originally Posted by Ed_Dinning

The EL33 is not uncommon and has some equivalents as does the AZ31.

You can use a number of valves in place of an EL33 including the very common 6V6. There will probably less gain overall because the alternative valves have less gain (lower slope), but this shouldn't be audible in most cases. If you make this substitution you should check the operating conditions of the valve to ensure it isn't being overrun - you may need to increase the value of the cathode resistor.

Paul