I certainly agree with Don. There are two effects that can enhance signals at low audio levels, often dramatically.
One effect is the response of human hearing. Hearing responds more the differences in levels with low level sounds. As the sound volume increases, we perceive less and less difference in levels. (Our vision is like that too in how it responds to light levels.) The other is the system AGC configuration. If you reduce the signals below the AGC threshold, the level between the signal and noise (S/N ratio) will increase, sometimes dramatically. That's exactly why some of us turn AGC off and ride the RF gain control, relying on the K3's hard limiter function to protect us from any huge signals appearing in the band pass. (That's why Wayne included a hard limiter in the K3 under CONFIG:AF LIM. It's active any time the AGC is turned off.) 73, Ron AC7AC -----Original Message----- There is some leakage between ANT1 and ANT2 -- so you just switched in an attenuator of some unknown value. I will wager you had the preamp on too. Next time, you might want to try turning off the preamp to lower the noise, and possibly turning on the attenuator. That way, you do not have to switch to "no antenna", and you can answer the station without changing antennas. 73, Don W3FPR On 6/5/2011 4:52 PM, [email protected] wrote: > I was working a weak station with QSB that was at about my S4 noise level. > Happened to hit ant. 2 button. Now the noise is gone but I can hear the > station weak but now solid copy. Interesting indeed! 72 Geo/W2BPI > ______________________________________________________________ ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
