I would concur with Don. I do not use the preamp unless the noise level is very low. I use the attenuator on load bands or when there is a substantial noise level. I use AGC as I don't want to damage my hearing accidentally.
Bill K9YEQ John, I find that true too - but ONLY under the following conditions: 1 - the preamp is turned on 2 - the attenuator is off 3 - I set the K3 to hear only noise (no signal) If I set the preamp off and attenuator on (normal operation with my 80 meter antenna) and then set the AF gain to listen to normal signals, the K3 is less noisy with no signal than using other settings for the AGC Threshold. In other words, you cannot listen only to the noise level and make a valid comparison. 73, Don W3FPR On 10/8/2010 12:08 PM, John Chappell G3XRJ wrote: > Don, > > What I should have mentioned in my initial post was that the recording > was made at midday on 80m and the noise from the antenna was only s1. > For a given setting of the rf gain, increasing the threshold to 8 > increases the noise, as can be heard in the recording. > > John G3XRJ > >> The solution is to RAISE the threshold. I run mine at 008 which is the >> max. I also run the slope at 002 which makes the K3 AGC response more >> like my K2 - weak signals sound weaker than stronger signals. You can >> alter the slope without running into the situation where the K3 sounds >> noisy, but the signals will sound more nearly the same as the slope >> numbers get larger. >> >> If your local noise is high, increase the AGC threshold and the K3 will >> quiet down. >> There is yet another way - turn off the preamp, and even turn on the >> attenuator. You will have to increase your normal AF Gain a bit, but the >> noise will be reduced. If you can still hear an increase in the audio >> output when the antenna is connected, you can even reduce the RF gain. >> You are not increasing the USABLE receiver sensitivity by running >> everything at full right controls - in the presence of atmospheric >> noise, that will only reduce the usable dynamic range and will make the >> receiver sound noisy. >> >> 73, >> Don W3FPR >> >> > ______________________________________________________________ > 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 ______________________________________________________________ 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
