Don, I tried your recommendations and it makes the setup sound better than where I had it. The threshold increase makes quite a listening difference for me personally. Thank you for sharing.
Bill K9YEQ -----Original Message----- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Don Wilhelm Sent: Friday, October 08, 2010 1:56 PM To: m...@paxsen.com Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 AGC THR doesn't go low enough I seem to have trouble convincing some to raise the threshold to combat the noisy effect. Please read all below carefully, and I believe I can offer some explanation. Let's study what the AGC SLP and AGC THR settings do and try to relate them to the perception that the K3 is noisy. IF -- the threshold is so low that the noise triggers the AGC (and that will be happening if the noise is causing the S-meter to have a reading with no signal) AND -- If the slope is set to a high value which makes all the signals have more or less the same audio volume, THEN -- The noise will appear at about the SAME audio volume as the signals. RESULT -- A K3 that sounds noisy :-( ! It is a combination of both the threshold and the slope that create this condition. The cure for that situation is to increase the threshold and reduce the slope. How much? That is an individual decision, but I have mine set to the extremes of THR at 008 and SLP at 002. I really believe the defaults are OK for a band where the ambient noise level is lower, but certainly gives problems on a band that is inherently noisy. Please make your evaluation while listening to signals and the breaks between signals - if you are hearing only noise, you will naturally turn the AF Gain up, and yes the noise will increase - not only that, with only noise, the perception is that one should use a lower threshold setting. That is because as you lower the threshold, the AGC response to the noise gets stronger, and the audio level is reduced by the AGC - what you are perceiving is exactly the opposite of what you wish to achieve. In addition, turn the attenuator on and the preamp off - again, if you hear an increase in the band noise when the antenna is connected, you have all the sensitivity that you can use for that band and antenna. The K3 remembers those settings by band, so you don't have to make changes as you switch bands. 73, Don W3FPR On 10/8/2010 2:23 PM, Mike Scott wrote: > I have thought about John's wish for more AGC control. The K3 has a > lot of gain, I wonder if greater attenuator control would be more > useful. I would like to rotate in another 10 or 20 dB attenuation at > times when operating lower bands. I would guess my that wishes would > require hardware modifications and John's may not. > > > > AE6WA > > Mike Scott > > K3, KX1 > > > >> John G3XRJ said: I've played around with various AGC settings and in > particular the > > AGC THR - which if it would go 2 or 3 points lower would appear to > > address the problem. > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
