[AMRadio] 2.5 Volt Tubes in 1936 HRO

[Donald Chester]

> Bama only has a manual for 6.3 volt tubes....can anyone provide the 
> 2.5 Volt
> tube complement for me? Many thanks....Jeff...W0XV


Jeff,

The only  difference is what tubes are installed in the receiver, the 
tube type numbers stamped on the tube sockets and the filament winding 
voltage on the power transformer.  Otherwise the receivers are identical 
in every respect.

The Bama manuals may be for later versions of the receiver, which did 
include some minor changes, after National went 100% to 6.3 volt tubes 
around the beginning of WWII.  The earlier receivers were available from 
the factory with either series of tubes, although they preferred the 2.5 
volt ones because they were said to be lower noise (and also because 
they had a large stock of 2.5 volt tubes on hand that they needed to get 
rid of).

Don k4kyv