Re: {Collins} 75S3-B S meter seems way too optimistic

Also, the AGC threshold should be about 3uV, which is how one sets the IF
stage gain using a signal generator. Set the generator at 3 uV output on
20m, and adjust the IF gain pot until the s-meter just starts to read.  This
adjustment should be made before setting the S-meter zero and sensitivity.
The 3 uV AGC threshold is typical of nearly all vacuum tube radios. However,
if a rig is primarily to be used on 40-160m, then I like to set it about 6
uV, or even a bit more on 160m. Modern transceivers often let one set the
AGC threshold individually on each band.

Jim W8ZR

> -----Original Message-----
> From: wa1rkt@xxxxxxxxxxx [mailto:wa1rkt@xxxxxxxxxxx]
> Sent: Sunday, July 03, 2011 9:58 AM
> To: collins@xxxxxxxxxxxxx
> Subject: Re: {Collins} 75S3-B S meter seems way too optimistic
> Just for a point of reference, 50 microvolts is S-9 (it's a little
disheartening how few of
> today's hams know that). So if you have or can get access to a calibrated
signal generator,
> set it for 50 microvolts at the input to your receiver and it should read
S-9 on the meter.
> Rick WA1RKT
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