[ARC5] BC-453 Current Draw

[Bill Cromwell]

Hi Scott,

There are several reasons to run from lower B+.

My own number one reason was to use batteries and eliminate conducted 
power line crud into the radio through the AC power supply. If you have 
*clean* KW AC utilities where you live you could never understand. Lucky 
you.

At the lower current draw batteries last longer. We can take the radios 
with us camping and to the park or Field Day.

With battery operation we can still play radio when the power lines are 
down. If your power lines never go down you would never understand. 
Lucky you.

At lower current draw - lower power consumption - the radio runs much 
cooler and is more stable.

It's experimental operation (non-destructive) to determine the 
boundaries of operation. Most curious people will sooner or later wonder 
about things like this. The OP wanted to know about current draw to 
determine if his proposed power supply will be adequate. It seems so.

Dennis has pointed out that the radios can be run with the *old* 
(ancient) leaky caps with the lower voltages.

Why *waste* power when the radios give satisfactory performance with 
less power?

So there are several reasons. I hope this helps.

Among the experimental results we also found some reasons to not go too 
low..

If you must rattle the neighbors windows with *loud* audio do not use 
lower voltages <evil grin>. These radios are likely to never be quite 
that loud. Some radios will quit before others as the voltages get into 
the far lower reaches. Obviously you can't play radio at those lower 
voltage levels if yours won't. Apparently we can lower the B+ even more 
if we change the biasing - something that should be obvious if we think 
it through. Where will we draw the line for modifications? Eventually 
our super mods will not resemble a command receiver.

73,

Bill  KU8H


On 01/21/2015 01:43 AM, Scott Robinson wrote:
> Folks,
>
> I must be missing something. With KW at your friendly neighborhood 
> mains socket, what's  the interest in running a receiver with big 
> heater mains tubes (valves) on such low B+?
>
> Curiously yours,
>
> /scott
>