Robbert you are correct it is a PYE but they used the Astor Big Bow chassis. I have one that I totally restored and it's a tremendous performer.
Not worth much ( it was a freebie to me ) but it really performs like I can listen to the Philippines on it very clearly.
Photo 9 in post 8 is a box full of those Air Trimmers if any of you want them.

How does one tell, other than the plates coloured, red for embarrassing, blue for sheer terror; that an output tube is getting too hot?

Normally if you can't burn your fingers on them and rectifiers, there probably not powered.

Marc

Easy - the plastic case behind was getting melted. It wasn't enough to be readily noticeable, but I could see that damage was starting to occur.

So I changed the 150 ohm resistor to 330 ohm which raised the bias from -5 to -10.5 volts. Still not quite the expected -12.5, but it will do.

And I think that if a tiny 7-pin valve is much too hot to touch then there's something wrong. It's not like a physically larger valve where the heat can dissipate.

I did a bit of other work on the radio - both the 6BE6 and 6BA6 cut out when touched. Cleaning the pins fixed that. I cleaned the dust and white dots off the case and left it to dry - I'll put it back together tomorrow. The knobs that came with it are the wrong ones but I don't think I have the proper ones.

Lastly I had a look at one of the Krieslers, I opened the record cover with a loud screech, and to my surprise there was a LP record sitting there on the platter. Not exactly desirable though - one of those Reader's Digest things with somebody's orchestra performing tunes that will "never be forgotten". I've never heard of any of them. Anyway I gave the record a wash to get rid of the dirt and so on. It might get used for testing.

Next, I cleaned the case and found it wasn't wooden but bakelite - it was so dirty that I couldn't tell. There's no markings anywhere as to what model it is. I removed the cardboard base and then had to undo the wires to the turntable, there's no plugs and no slack. Although the components are ancient, the valves are 9 pin types.

6V4 (old double-decker type) hard up against the tuning capacitor; 6AD8, 6M5, 6AN7. No markings on the last 2, but they aren't exactly difficult to guess. There's lots of wax caps to replace, so I'll look at that next week.

one of those Reader's Digest things with somebody's orchestra performing tunes that will "never be forgotten". I've never heard of any of them.

Well, I guess if you've never heard of them then you can't forget them

The resistors in many mid, to latter fifties sets tended to have batch issues and were unstable. Many plastic sets were made brittle above the two seriously hot tubes. Tubes like EL 34 have a running limit of over 400degress Fahrenheit (200C) nominal is 300 Degrees F, for most output tubes. Never unusual to see an Asbestos mat above them.

The biggest issue with OP tubes is their ability to destroy control grid resistors and bias. The greatest destroyers of bias are waxed paper caps and many oil filled types. If the coupling cap is below 200Megohms working volts it will bleed positive onto the grid of the next tube: That will bring it closer to a diode and that can destroy it. I would never consider alterations to a circuit until I cleared out the feral bits.

Even after close to sixty years, I will not waste time fault finding, on a set full of worn out electrolytic caps and known to be leaky non-polarised caps. Much can be achieved by bringing the set into compliance with its factory wiring

No arguing with you, is there.

All those parts had already been replaced. I'm quite well aware of what leaky caps can do.

Besides, there's another reason to reduce the heat and wasted power consumption, that being the cost of electricity these days. If I can see a way to save 10 watts of wastage I'll take it.

The biggest consumers of power tend to be the heaters & filaments. The best you can do is get rid of the leaking caps & such. There are normally ramifications, for messing with the circuit and getting it out of compliance. Frequency changers do like their 250V to remain stable.

I sold off most of those cabinets at the last HRSA meet and more than broke even plus the buyers got a real good deal.
I had a quick look at one little cabinet and found it to be full of new old stock mustard caps so guess who got to keep them ? Oh and a massive roll of professional dial string didn't go astray either .

Had a look at the radiogram from post#18, the 6M5 was gassy and the usual leaky caps around it, after replacements it works well. Still need to replace a bunch more wax caps to complete the job.

First time I've encountered a faulty 6M5.

More from the radiogram - I've put it aside for the moment - it receives as long as it has a long-wire attached - without the wire it can only pick up my house station. The dial is way out, probably 150kHz or more. So it will need alignment when I get back to it.

The record player is stuffed - the cartridge is broken and needs replacing which I won't bother with - the rubber wheel has a knock in it, and the speed selector is faulty, unable to choose one speed. The other speeds run too slow because of the worn wheel.

Then there's the Radiola - put it back together and now it hums like crazy, so the first filter cap (at least) will need attention. I'll get back to it eventually.

And lastly, the other radiogram which hasn't been mentioned until now. It's also a Kriesler, this time in a wooden box. I haven't powered it up but the record player appears to be already non-functional, with the metal turntable falling out when I turned the thing over, and the stylus missing. Just like the other radiogram it has 4 valves in a reflex arrangement. ECH35, 6B8G, 6V6GT/G, 6X5GT. Again no indication of the model number, but someone has already recapped it with mustard caps, so perhaps it might work when I try powering it up, next week. This one has a shortwave band, too.

Accessibility is a problem with these radiograms - it took a while to find the hidden screws and so on, plus the fact you have to unsolder lots of wires before the chassis can be removed, in case you need to replace a valve or dial lamp.

you have to unsolder lots of wires before the chassis can be removed, in case you need to replace a valve or dial lamp.

What a triumph of design.

Some designs are brilliant (sic) Have an Astor car radio on the bench. There are caps in tubes through the chassis and even with tubes out its a horror story, Even has to repair one of them as the top cap was off: Tested before repair.

The "piece de resistance", also seen in a Stromberg Carlson is putting three guaranteed to be dodgy, paper caps under the tuning gang. SC put theirs under the Wave change switch box.

Well another day another discovery. While above appears to be an Astor 8662 Circa 1937 its a badge engineered job. It apparently came out of a Dodge and I know which one: Its still going.

In a moment of Zen enlightenment. GMH used Firestone radios (Air Chief); Ford England HMV / Smiths (Radiomobile ?); Chrysler-Dodge locally Astor, but in USA many were Philco.

So after realising I was overlooking that, it looks like its actually in "Rider" as a Philco "Chrysler C-1452" 1937 which the "D" ARTS&P label (or what's left of it) is consistent with.

Wow that Zenith transoceanic would've been awesome!

The second radiogram mentioned in post#25 won't be working any time soon, as the speaker transformer is blown, and I can't be bothered right now with doing anything about it.

The turntable motor runs but with a loud squeak. The rubber wheel is intact (no bumps) but is as hard as a rock. I had to disconnect all the wires for the turntable so I could gain access to the chassis.