[MrFixr55]

Hi Morzh, History of the World Part Zero should be the "working title" for the movie "Strange Bedfellows" or visa versa.

[Chris Cusick]

Dear All,

Thanks for your interesting comments - here is a quick picture of the set minus the back, showing  the Mazda tubes in all their zinc-coated glory .

Its interesting that BTH were a subsid.  of GE originally since they were later acquired by GEC in the sixties.  I remember their Rugby plant was still going in the early eighties as part of GEC. 

(What happened after that is probably better not to discuss !)

Cheers,

Chris

[RodB]

Is that A battery a wet cell or two dry cells in series?

[morzh]

We did have some spray shield on some tubes, back in the old country.
I had one in my collection. Tried to find it on Google, no dice...

Then I asked in Russian while using "spray-coating shield" expression because I did not know the exact Russian one.
It immediately gave me some examples.

So, if you type this "2Ж2М", it will find you the images.

[Chris Cusick]

Hi Rod,

It is a 2V sealed gel type rechargeable battery. Capacity is 4.5 AH. Apparently they are used with model cars and such. It seems like a good way to replace the old glass accumulator. I think it should be good for about 10 hours between charges. We shall see !

Best Regards,

[RadioSvit]

""""One company that used North American tube types almost exclusively was Kolster-Brandes, a K-B is one of the handful of British built sets I own, they were owned by Standard Telephone and Cables, which was a division of International Telephone and Telegraph. """

Hello everyone. Arran, you surprised me with this information. I have a battery-powered British Kolster Brandes KB530 from 1936 and it is assembled on British 7-pin lamps. This is a three-lamp farm regenerator with a 120 and 2 volt battery. Here is a photo of it.
Perhaps you wrote about Canadian or American Kolster Brandes models?
   
   
   

[Arran]

That's a pre war Kolster Brandes, but almost all of their post war stuff seems to have used North American tubes, like the "Toaster" sets. It looks like they began doing this in the late 1930s, or early 40s, but then again they had their own tube plant, I'm guessing that they figured it was less expensive to manufacture octal based tubes then to make one with banana plug type pins. Pye and EKCO liked to use Mullard/Phillips style tubes, they did not manufacture EKCO sets in Canada, nor Kolster-Brandes sets, the one I own was imported from Britain and there is no provision for 120 volt operation. I'm not even certain that they manufactured Kolster sets in Canada, though one 1927 era battery model keeps popping up, usually with some bad pot metal in one of the controls. Pye briefly manufactured radios and TVs in Canada, using North American tubes rather then Phillips types, but they seem to have dropped out of the market around 1954-55 in favor of commercial equipment like taxi and marine radios.
Regards
Arran

[MrFixr55]

Hi Peter,

That set interested me, especially when you stated that it used regeneration, so I went to Radiomuseum to pull the schematic. I immediately thought of the Philco 80, 84 and 37-84 which used the same technique. I thought that was a Philco exclusive in multitube radios (Granted, most of the single tube or 2 tube radios, at last the Westinghouse and GE sets sold by RCA used the Armstrong superregenerative circuit that RCA owned the patent for), until someone mentioned the Atwater Kent 944. The major difference is that the Philcos and A-K were Superhets where the K-B you mentioned is a TRF. There were many TRF sets that were 3 tube plus rectifier in the early 1930s using a pentode RF, a pentode biased detector and a pentode audio output. Rectifiers were either 1-A, a 37 triode used as a diode or the 25Z5. These sets were popular because they were cheap and cheap was needed in 1933.

[RadioSvit]

Aran, MrFixr55, I understand you. Thank you for the interesting information.

[Arran]

Mr Fix;
Part of the reason for the low tube count in that Kolster-Brandes was obviously for battery life, but the other reason was that the B.V.A charged a "license" fee of 1 pound per valve. There was also apparently a silly stipulation that a valve could not have more then one section on the same envelope, but I think that may have ended before the mid 1930s. So they used to employ tricks like regeneration, and reflex circuits, things that were basically gone in U.S sets by the mid to late 1920s as tube prices came down, and AC sets took off.
I have noticed that Philco seemed to design circuits around patent royalty avoidance, like the infamous "autodyne" oscillator-mixer circuits, the model 19 and 89 seem to be based on this reasoning as the Model 60 debut in 1933 and used a proper pentagrid convertor 6A7. The set you mentioned I have had a few, basically city sets, the gain on one I have is actually not bad, but the selectivity is not with only a two gang tuner, they are the type that sold for under $10 in some cases in discount stores.
Regards
Arran