[ARC5] Receiver current drain

[Neil]

> I know that the dynamotors are rated at 250 VDC at 60 mA, but what do the 
> receivers NORMALLY draw when in operation.

The 12A6 audio tube is the one that will draw by far the most current when it
is correctly biased to drive a loudspeaker. We must remember that in military
service, this tube was driving headphones at the 100-200 mW level so there
was no requirement to generate a large amount of audio. The 12A6 cathode
bias resistor of 1600 (?) ohms reflects this. The value is high, tending to bias
the tube somewhat further towards cutoff than it would be in normal application
where the value would be 400 ohms.

Contributors are suggesting a range of currents, but they aren't specifying the
resistor's value so we don't know the 12A6 operating conditions. OTOH, some
owners have in the past reported adequate audio output into a loudspeaker
even with the original value, so this whole issue may be moot. I thought it has
a bearing on the question, and is something that needs to be appreciated in its
own right anyway.

73 de Neil ZL1ANM