[Elecraft] RF gain sweet spot

[Wes Stewart]

I believe that all this does is prove what I have said many times for over two years---every K3 is different with respect to its RFG/AGC characteristics.

The RF Gain "calibration" is an attempt to fix this variability.

--- On Thu, 7/21/11, Edward R. Cole <kl7uw at acsalaska.net> wrote:

From: Edward R. Cole <kl7uw at acsalaska.net>
Subject: Re: [Elecraft] RF gain sweet spot
To: Elecraft at mailman.qth.net
Date: Thursday, July 21, 2011, 11:13 AM

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
======================================
BP40IQ   500 KHz - 10-GHz   www.kl7uw.com
EME: 50-1.1kw?, 144-1.4kw, 432-100w, 1296-60w, 3400-?
DUBUS Magazine USA Rep dubususa at gmail.com
======================================

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html