[ARC5] Re-reading Gordon White article...

[Kenneth G. Gordon]

On 6 Jun 2013 at 12:43, J. Forster wrote:

> ???
> 
> I just looked at the print and L-2 is in the plate circuit of the 12SK7 RF
> Amplifier, and sees the received frequency.
> 
> -John

Yes. Exactly. Weird, but obviously done for some very good reason.

I would really like to know what that reason (or reasons) might have been.

One other factor here that brought this to my attention was that I was "finding" the peak in the 
RF input circuit of a 1.5 - 3.0 MHz receiver the other day (when I suspected that a previous 
hacker had modified the coils), with all the tubes removed, and found that the peak in the 
tuning of the RF stage is at least 100 KHz LOWER than the dial reading, yet with everything 
in place and operating, the RF peaks in the correct place.

I had connected my signal generator to the antenna connector, and had connected my 
'scope to the grid pin connection on the RF amplifier tube socket, then adjusted the signal 
generator frequency for a peak in the signal on the grid. The peak is actually quite sharp too.

Ken W7EKB