In SolderSmoke 131 I talked about this old homebrew receiver. I picked it up at a radio rally in London and almost sold it at a hamfest in Virginia. A fit of UK nostalgia provoked by a screening of “The King’s Speech” caused me to hold onto it. Now it is luring me into two areas that I don’t really want to get into: high voltage and regeneration. But here we go… I turn now to our British cousins: What can you tell us about this receiver? 1920s? 30’s? What tubes should I be looking for? How would they have powered this receiver? Does anyone have a schematic that might describe this device? (Or something close?) 
The King’s Speech Regen
We just saw “El discurso del Rey” (subtitled, for the XYL’s convenience at Cinépolis), and yes, the movie is worthy, and all of the art direction, in particular, really creates a period mood. The old radios are cool. This hb regen you have is a thing of beauty. Thanks again for the components, and the mention of GDL numerous times.
The machining marks on the front panel look something like the cowling on the Spirit of Saint Louis http://www.jpbellphotography.com/images/large/SpiritOfSt.LouisLIT77B&W.jpg Maybe it was an aircraft radio… hi. Bill N5AB
Looks like you might have a British-built set there. The tube (valve) bases are British 4 or 5 pin and the plug-in coil looks to be an Eddystone type. Probably the tubes you’d need would be a PM2 in the regenerative detector, socket next to the coil and something like a PM2HL AF output stage. Those tubes had 2 volt filaments. 73 Roger/G3VKM
go to http://www.eddystoneusergroup.org.uk/ there’s lots of info…find the short wave manuals … there are also building instructions for late 20s / 30s regens [TRF in British English] It wouldn’t take you long to trace the circuit 73 ~~John g8jmb
If you are interested in a making a regenerative radio using standard transistors I have a book: http://www.webstore.com/91359,owner_id,other_items I have free circuit ideas here: http://code.google.com/p/lemontree/downloads/list http://circuitprofile.scienceontheweb.net/