Bakelite

[pwdrive]

Cheers for that Nick.

Lawrence.

[Mark Hennessy]

Hi Lawrence
I don't want to take this thread off topic so I have sent you a PM in answer to your question.
Nick

Honestly, we're really very relaxed about that sort of thing over here. If in doubt, just go for it - we can always split the thread or similar if needed, but that only happens occasionally

All the best,

Mark

[SurreyNick]

Thank you Mark, I shall keep that in mind.
I sent the following PM to Lawrence in reply to his enquiry about the three-valve TRF

Hi Lawrence

The three-valve TRF was based upon FJ Camm's book; A Beginner's Guide To Radio, of which I have a first edition. I wanted to see if, in practice, the receiver could actually be built by following his direction and how well it would work. It could be built, but only in a manner of speaking. Numerous inconsistencies and omissions in the book rendered it difficult, if not impossible, to construct the fully evolved iteration he described. But I got as close to the complete thing as I could decipher and that's what I set out to construct using original 1920s and 1930s components. The only exception I allowed myself was using a wound coil rather than just two coiled loops of wire for the tuning and reaction coils and a custom-made breadboard cabinet with the components on show. Other than that, all the components were as specified by him and took quite a while to track down.

As for the coil I used modern acrylic instead of shellac coated cardboard for the coil but other than that the design is based on one of Camm's from his book Wireless Coils, Chokes and Transformers.

I will get around to building it one day.

Nick

[Alan Douglas]

Numerous inconsistencies and omissions in the book 

I've forgotten who it was, but one of my friends referred to his magazine as "Camm's Comic."  If you're in the publishing business it's "publish or perish" even if your readers sometimes become your proofreaders and testing staff.

[SurreyNick]

Very true Alan
I think some of the errors that appeared in the first edition were later corrected, but nevertheless I think the circuit was only ever theoretical and not actually built and tested in practice. I did end up with what I believe is a workable circuit for it though. That's part of the fun for me - seeing if some of these old circuits can still be built today with original vintage components.
Nick

[Alan Douglas]

There was a weekly magazine in New York City, Radio World along those lines, where the published circuits might or might not have been built and tested. It was a one-man show for editor Herman Bernard, and I'm not sure that some of the pseudonymous authors weren't Bernard himself. Jim Millen wrote occasional pieces so he knew Bernard, and he once explained the publishing process to me. Bernard basically did everything from collecting and editing the material, to taking it to the printer and delivering the magazines to news stands. It took seven days and then started all over again. He never missed a deadline in over ten years from 1922.