[ARC5] AGC in the AN/ARC-5 receivers.

[Fuqua, Bill L]

  Yes it is delayed AGC. I was simply saying 20 Volts is way too much.
a few volts perhaps. 
   The simplest way to determine the delay voltage is simply to 
measure the cathode voltage. I remember studying AVC circuits 
in high school electronics class. And we discussed delayed AVC.
   Final exam was to draw a schematic of a superheterodyne 
receiver with BFO and approximate values for all the components.
I was one of the few that got it all right. I was also the only
ham in the class. hi hi hi. It was a heck of a class taught by
Hugh J. Phillips.  A very interesting fellow.

73
Bill wa4lav


________________________________________
From: Kenneth G. Gordon [kgordon2006 at frontier.com]
Sent: Saturday, November 02, 2013 11:51 PM
To: Fuqua, Bill L
Cc: Arc5 at mailman.qth.net
Subject: Re: [ARC5] AGC in the AN/ARC-5 receivers.

On 3 Nov 2013 at 3:23, Fuqua, Bill L wrote:

>   That would be over 50mA current for the tube.
> And around 1W dissipation in the cathode resistor.
> Does not sound right at all.

See and read page 23 of the AN 16-30ARC5-2 manual, paragraph 4-18
AUTOMATIC VOLUME CONTROL.

I thought it was a bit much myself.

I suppose there COULD be a typo.

I measured the AGC voltage with a VTVM when the RF gain control was
wide open on 5 MHz. WWV in an R-26/ARC-5 receiver recently.

AGC voltage was 8 VDC...and the audio level was WAY too loud to listen to
for more than a few seconds.

Also, however, AGC voltage didn't even begin to show up until the audio was
already too loud to listen to for very long.

There IS a big "delay" voltage...

Ken W7EKB