[Elecraft] RF gain sweet spot

[Don Wilhelm]

Ed,

I suspect he was not using a K3 because he said the S-meter did reduce 
when the RF Gain was reduced.
You could turn off the K3 preamp and turn on the attenuator and see if 
that drops the ambient noise level.  With your external preamp, I 
suspect you can reduce the K3 gain substantially.

73,
Don W3FPR

On 7/21/2011 1:13 PM, Edward R. Cole wrote:
> K7WIA's experience with his 6m receiver got me to try this with my
> K3.  I have an ARR P50VDG preamp installed and see typically S4
> flickering up to S5 for noise connected either 6m yagi.  Reducing
> RFGain immediately increases s-meter reading with the ARR preamp so I
> switched it off.  Noise is almost not readable on the s-meter and
> reducing RFGain does not result in increase in s-meter reading until
> I rotate the RFGain less than 3-oclock postion.  There is not enough
> s-meter resolution to tell if there is any reduction in noise (none
> detectable by ear until s-meter begins to rise).  Finally, I tried
> this with the internal K3 preamp turned on.  Normal noise reading is
> S3.  Reducing RFGain exhibited the same as not using any preamp
> except s-meter stays at S-3 until I rotate below 3-oclock position
> whereby the reading climbs above S3.
>
> Considering that I am in rural Alaska I should have less ambient
> noise floor than K7WIA but do not see the behavior he is
> seeing.  Comments?  I would be interested to know if he is using a K3
> (radio was not specified) and whether that was running with a preamp
> and what kind?
>
> My take on my readings is that the ARR has more than enough gain
> (maybe too much) and I am seeing amplified noise.  But I do not get
> the s-meter behavior seen by K7WIA when reducing RFGain?
>
>
> 73, Ed - KL7UW, WD2XSH/45
>