[ARC5] Receiver Voltages.

[Kenneth G. Gordon]

On 1 May 2015 at 0:19, AKLDGUY . wrote:

> The "power hungry" nature of the screen divider resistors is probably
> by design and intended to secure better regulation of the screen
> voltage to all stages.

I agree.

> I understand that the ARC-5 receivers had AVC, while the ARA and
> SCR-274-N receivers had manually controlled gain. The screen currents
> of the controlled tubes therefore vary with gain setting.

Yes.

I also find it interesting that the screen voltage on the RF and IF amps is 
about 125 VDC normally, whereas in the RCA tube manuals, that voltage is 
normally 100 VDC for a Class A RF amp. Perhaps this is one reason why the 
sensitivity of our receivers is quite good.

As I have repeatedly said here, in my opinion, the ARC designers were sheer 
geniuses. They, apparently, thought of everything.

Ken W7EKB