[ARC5] mysterious find

[john rose]

The things you find looking for something else.

I've been searching the net for a scan of a manual. I stumbled across a forum site where a complete list of SCR equipment is posted. I think I found a gem, never seen the list before.

http://g503.com/forums/viewtopic.php?p=971691

Here is the mystery. There are 2 listings for things I've never heard of before.

SCR-274A Predecessor of SCR-274N Rcvrs BC-394A, 200-400 KC, 395A, 4.2-7 MC.
 Xmitters BC-392-A, 4.2-5.5 MC and BC-393-A, 5.5-7 MC 
SCR-274B Predecessor of SCR-274N Rcvrs BC-394A, 200-400 KC, 395A, 4.2-7 MC 
 Xmitters; 2 BC-932* 

Anyone ever hear of these?