[Milsurplus] BC-348-R

[WA5CAB at cs.com]

Joe,

As others have already said, it's connected properly for a 500/600 ohm 
audio load.

They stopped doing it with what are generally known as the Korean War era 
sets and went to nominal 500/600 ohm audio transformer secondaries.  But the 
30's/40's vintage stuff had 4000 ohm (Army) or 250 ohm (Navy) outputs until 
'43 or '44 when 250 ohm taps were added to the audio output transformers in 
the Army sets.  The rationale was as follows.  The most commonly issued 
loudspeakers and headsets were 7000/8000 ohm then 500/600 ohm (Army) and 500/600 
ohm (Navy).  From one to four loads could be jacked into the source without 
more than a 2:1 impedance mismatch.  

In a message dated 3/20/2010 9:45:40 AM Central Standard Time, 
joeconnor53 at yahoo.com writes: 
> I need a little help. I just picked up a nice, unhacked BC-348-R. On the 
> front,there is a label that says: "NOTICE: connected for low impedance 
> output." What impedance is that? I used a speaker with 500-ohms impedance and 
> the output is a bit low. What should I be using?
> 

Robert & Susan Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480