[Milsurplus] BC-654

[mac]

Used in (and maybe designed for?) pre-war police radios.  The 5.5 volt  
filament was probably to accommodate voltage drop in the 6 volt auto  
systems of the period.  The Coast Guard T-100 aircraft transmitter  
also used 307A's.

Dennis D.  W7QHO
Glendale, CA

On Sep 21, 2009, at 6:18 PM, Thomas Adams wrote:

> The 1948 Editors and Engineer's Radio Handbook claims that the 307A
> was used in ONLY
> ONE hunk of equipment; the BC-654!