The AM Forum

Investigated this little jewell yesterday. Made up some techncial notes and took pics. Schematic included. Nice grid modulated AM TX set covering 2 to 4.5MHz.

A 1613 is used as a modulator. I do not find curves for it as a class A amp. Is it equivalent to something else, like a 6F6?

Has anyone tun one of these, or has an interest in this kind of thing? Not much on the WWW. It's a treasure trove of parts, but I don't want to part it. The front/exterior is not corroded yet very paintless and dirty, but inside - nice and clean.

http://www.bunkerofdoom.com/mil/bc653a/index.html

The following military VT to civilian equivalence table says the 1613 is a "selected" 6f6.

http://pages.cthome.net/fwc/VT.HTM

I had a shot at one of these beasts at the first Nearfest but when I came back from hauling out a load, it was gone. My first receiver as a novice was the receiver that goes with it, the BC-652. Only good on 80M and fast tuning but that radio was the one that got me hooked on surplus. I have since recollected one of these receivers complete with the dynamotor. see pics.

I think the 653 is screen modulated if I remember right. It may be the least power per pound of any of the WW2 radios (on AM at least)! The WW2 doctrine was CW = long range and AM was used only for short range intra-unit coms.

Mike WU2D

Does your BC-652 use the 12V or 24V dynamotor?

You should also have the matching transmitter!

I think if a DM-42 or DM-43 could not be found, a supply could be put in the slot. I do not know the current requirements, perhaps 200mA @ 1KV and 100mA @ 500V, but I do know where more dynamotors than a man can carry are secreted, and fair radio has the maintenance manual.

Its' rated 25W carrier, but the tube pair will do 50W carrier on AM at the same 1KV the rig runs at, according to the ancient and dusty tomes. With the 807 driver.. might do it.

NH is a long way for shipping 100LBS from TX, but you would not regret it. and neither would I, because some day this fine instrument will become parts or worse if someone does not care for it and restore it. I have surprisingly little in it, bought by the pound. Please PM if interested, I have too many radios and I'd like someone to have it who collects and who might actually put it in the air.

UGG! A beautiful if impractical thought! And Geez ship it to New Hampshire from TX? it would take some serious boatanchor dollars just to transport such a beast, but thanks for thinking of me!

Mike WU2D