Identifican request - 3 Valve mains superhet

[Refugee]

It sounds like there is either an open circuit resistor or short circuit capacitor in the AGC line or maybe a bit of perished wiring touching the chassis.
Just try shortening the aerial and see if it comes up any more.

[Crackle]

The small round ones, photo 2 dont seem to work at all.
I would think the diodes in the 3rd photo would be more reliable, 2 out of the 5 I have seem to work with a resistance of about 4M one direction and 3M the other direction.
The most reliable seem to be the 4th photo type, 2 out of 2 seem to work.
I dont think you can test these on an ordinary Multimeter diode test.
Mike

[boater sam]

No, they need a forward voltage through them before they will respond I believe.

[boater sam]

A quick thought, could you have a faulty capacitor in the 2nd IF can? That would throw the IF way off frequency, your wire on the anode may be making up for it.

[Refugee]

Those diodes will need to be tested with an AVO with a good 15 volt battery in it.

[Sparks]

Terry,
Thanks. That is the Trader that I am using, but it is a much clearer copy than mine, but at the moment, defies all my efforts to print it out. Maybe it will print after I turn the computer off and on again!
Boater Sam,
Ideally, I would have liked to check them, but can't get the cans open. I could probably force them out of the chassis clips, but would not be able to get them back again!
Refugee
Wire touching chassis possible, as it is really in a mess with perished insulation.

So far, I have cleared 13 distinct faults, so it is quite likely there are more yet to find. Also, I must remember that I have a 6V6 in it instead of the EL38, so I will really have to change the bias to suit the 6V6.

When I do get it working properly on 220 Volts HT, I will most likely still make the new PSU 100 Volts, because I remain quite astonished at the performance on 50 Volts.

Bob

[pwdrive]

I don't think the original in these receivers was an EL38.

Lawrence.

[Crackle]

The Original output valve was equivalent to a EL33 or 6AG6G

The list is at the end of the trader sheet Terry linked to, but then you dont know if someone has already adapted it to another valve.

MIke

[boater sam]

The IF transformers should come apart easily once they are removed from the chassis completely. Try hanging a small value cap across the existing externally and see if it improves the set, then you will know.
That vertically mounted metal rectifier is bad practice, but it has worked for all these years!

[Sparks]

I haven't looked at it for two days on account of going out, and my 6 Volt LT batery needing recharging. I know that the cans would come open easily enough if removed from the chassis, but they can only be removed by brute force, and having been removed, I doubt if I could get them back! When it gets light, I will take a photograph to show you why! I could check them by disconnecting them underneath, and a connecting each half in turn to a home-made transitron oscillator to see exactly what frequency each LC circuit oscillates at! Plenty other things to look at before I have to do that though - the dreadful sate of the wiring for a start.
Bob