Picked up a wreck from the tip and can't resist the challenge of trying to get it going, and perhaps even looking OK.

This is a portable stereo radiogram. Style points to about 1960 but I can't find anything on AORSM, Radiomuseum or Kevinchant. Label says made by Pye in Sydney, cabinet has another maker's stamp but illegible.

Valve lineup is:
2 x 6BM8 (stereo output from gram)
1 x 6N8
1 x 6AN7
1 x rectifier - appears burned out and labels illegible, possibly 6X4 or 6V4?

Not plugging in for a while yet - will follow safe procedures to check from power forward first. Sending in a "before" picture so I can feel good about "after", however far I get with this.

Note the horrible lettering style on anodised aluminium face plate, cheesy plastic knobs. Relates to my earlier posts about Australian radio designers. Was this style ever considered chic?

A previous owner painted the speakers pink, and the insides of it smell like talcum powder! That young female owner probably in 70s by now.

Maven

You're in luck. Unhide your email address and I'll send you what I have.

(The rectifier is 6CA4).

Done. What a great resource this Forum offers!


Maven

Okay, sent.

Received with thanks

According to this advertisement from 1960, the pink speakers were originally "tangerine". The originally grey box has also acquired a greenish tinge. Thanks to decades of ultraviolet light.

I like Thumbelina jiving on the second speaker with Tom Thumb.

To be fair, while the aesthetics may be questionable, the ergonomics are quite innnovative. The ad shows one speaker half-opened, so projecting sideways, with the other speaker still closed, projecting upwards. Weird stereo!

With both speakers removed from the main case, they have metal tags on the back so they can be hung on walls if desired, about 4' apart, for "true" stereo. Stereo sound in 1960 had the status of 3D movies today - a modern marvel.

I don't really understand what they mean by the claim "8-valve performance". Perhaps I'll know when I get it running again.

Thanks for posting these pictures. Obviously Pye's Australian gramophones were quite different from the British models I remember. I doubt that the Stereo 22 was ever considered pretty. I don't think it's ugly, it just looks business-like, the sort of machine that a school might buy.

Most PYE stuff here was built by Astor. Do note with PYE and Astor (main offenders) That they had a habit of mounting a perfectly innocent looking Output transformer on an insulated mounting and then putting B+ on it.

Yes, this stereo model has two of those OP transformers with full B+ on the primary. The other end of that coil is pin 6 (pentode plate) on a 6BM8. Secondary coil of the OP feeds back to the cathode and second grid of that pentode. Beyond my understanding.

Maven

Ahhh different. They put B+ on the body of the transformer, HMV chassis 01 also used the tapped transformer with 6BM8 cant think of the amp type name at the moment but it did get a lot more noise out of them.

Marc

They put B+ on the body of the transformer

I'd categorise that as setting a lethal man-trap.

What's the justification for doing that?

To stop the transformers breaking down and developing B+ shorts to chassis. They didn't have much faith in the insulation of the transformers back then for good reason!

^ I can understand the transformer being insulated from chassis to avoid the effects of insulation breakdown, but why put B+ voltage on the transformer body -- if that's what Marc is suggesting?

I guess that if the transformer body is floating at B+ voltage rather than at ground, there won't be any potential across the insulation between coils and body. But I haven't heard of insulation material being broken down by potential - the usual factor is heat, I would think, or chemical deterioration over time. Potential-effect would have to infer some sort of electrolytic migration of molecules into or through the insulation material.

Maven

By putting B+ on the whole transformer that meant you actually only had plate to screen voltage across it. which took a lot of stress off of the insulation.

The "ISO" (insulated shielded output) transformer in the metal can quite often has its frame live: But you have to actually deliberately set out to get bitten by it.

Marc

Now I've replaced all electros and paper caps, plus a few resistors that were way off, and got an EZ81 to deliver B+.

But I seem to have a fairly gross alignment issue. Audio signal from tuned circuit is weak, and the stations I can recognise are Shortwave (BBC World Service) and what sounds like some Ham or Aviation conversations.

The docs (thanks GTC!) tell me about adjusting the IF transformers and the oscillator coil plus trimmers, which I have plastic tools to do. Before I start, I'd like to know whether I should be looking elsewhere for a tuning issue that is so far off the mark. The fixed caps in those tuned circuits are all either micas , or have been replaced. Could slightly off-spec resistors affect the tuning range?

Maven