[ARC5] Receiver Power Supply

[Mike Hanz]

It seems pretty clear that the "optimum" B+ is a variable, Ken.  Between 
your assessment and Leslie Smith's ~60 volt suggestion, it would seem 
that  a variable supply might be a good thing.  For the one or two 
people on the planet who might be interested, I have been fiddling with 
an idea that provides at least a modicum of flexibility, and combines it 
with a way to use your old dynamotor hulks.  It is still a work in 
progress, but such as it is at the moment is at 
http://aafradio.org/garajmahal/virtual_armature.html

Buttoning up the dynamotor end bells reduces the RF noise to about what 
you get with a standard dynamotor, but some adjustment of the original 
mica capacitors on the armature ends should reduce that even further.

73,
Mike  KC4TOS

On 4/29/2015 11:40 AM, Kenneth G. Gordon wrote:
> On 28 Apr 2015 at 13:36, D C _Mac_ Macdonald wrote:
>> I believe some folks here on the ARC-5 list, recommend keeping the B+ voltage
>> down around 175V or lower to ease stress on the old capacitors in the receivers.
> In my tests on receiver plate voltage, I have found that in several cases, the
> "best" voltage was "about" 170 VDC or so, although that is most certainly not
> a "hard and fast" figure either. It seemed to vary a bit between receivers.