I omiitted that the IF of the 556 is 252.5kHz.

STC830,
Yes please, could you send the 556 circuit.
That really sounds close.
Much appreciated. JJ

Circuits now emailed.
Decided to look in 1938 AORSM as circuits will sometimes appear in the following year.
So now have 556 and 558 with 43 and 45 output valves respectively. Both 252.5kHz IF. and 558 circuits has voltages.

Have you got an Acca/Dacca converted to Acca?

No I’m fairly sure it is a factory installed mains transformer. So AC only.
But it has had a lot of work done to it in 85 years.
Also has a 6V6GT installed via a man made with hookup wire adapter.
That’s the first thing that will be ripped out and a 42 installed.
Thanks again. JJ

It is amazing as to how well many sets work, when you bring them back into spec.(which includes correcting adjustments).

Do be aware that plate resistors on the det first audio, and grid of a 6V6 and others; Had a massive attrition rate.

Most of those sets followed a similar plot, & it just looks different. Once you have realised what the plot is, its much easier.

Update:
Radio is again working.
Found shorted 0.1mfd filter cap on 6A7 pentagram convertor oscillator anode feed.
Fed by wire wound 22K resistor off HT rail.

Cleaned up previous repairs and have now replaced remaining 7 paper caps. USA branded.
And checked remaining resistors.

Alignment done and seems sensitive and loud.

But unfortunately I will be spending more hours on this one as the detected AM audio just does not sound right.
The tuning seems fairly narrow and critical to get expected audio quality out of this radio.

So off to the detection, reflex, agc, design or monkey possible problems.
Maybe someone has some info on the 6B7S detection foibles.

General voltages and suggested manufacturers bias voltage all seen in the ball park for the valve line-up.
JJ

That rather sounds like a paper cap of which there should be none remaining..
A wire 22K sounds odd and wire wound resistors should not be anywhere near the RF.

If the IF has been adjusted such that it creates a narrow band, that can cause issues. Too much applied signal on the pentagrids signal grid can also cause the IF to be set wrongly, as can the use of the wrong IF frequency, due to the generator being out of calibration.

Marc

Final update:
Owner wanted radio back before Christmas.
Found I got reasonable audio results by flattening the final IF response a little, on next alignment.
Owner supper happy, so I have got it out of the way, without spending more hours.
My final thoughts were that the IF had far too much gain. Plus no accurate circuit. And please don’t mention reverse engineering.
As this unit has had lots and lots of work done to it over the last 80 odd years.
Anyway have said no to any more restorations/repairs/quick fixes or whatever for another month or two.
Have some of my own radios that have been waiting for years.
JJ