What am I hearing on my K2/100 when on exactly 7.000 plus or minus a few KC's I hear a steady tone when switched to the dummy load? At first I thought it was coming from my computer monitor but it's not. When I switch back to the antenna system the tone is gone or at least so attenuated I can't hear it.
k3ey Ron D'Eau Claire <[EMAIL PROTECTED]> wrote: Keith KD1E wrote: But is it the AF amp? I *think* (not sure) that I did a test with my K2. Listen to a dummy load and hear the hiss. Turn down the RF gain and the hiss goes away. I KNOW that was the case with my Omni V and I *think* that's the case with the K2 as well. If that's true, then the hiss is from the IF stages and changing the audio amp will do little. --------------------------- True, but you must turn down both the RF and AF gains controls. The "RF" gain control (actually it controls the gain of the I.F. amplifier) has a finite range. It won't silence the receiver. The AF gain control is also at the *input* to the audio amp, so turn it all the way down as well to hear the real noise output of the audio amplifier. On my K2, using sensitive headphones, there's no background hiss from the audio amp. It's all coming from the I.F and RF stages. I can hear the background noise increase when enabling the Preamp with a dummy load connected to the antenna port, so some of the background is originating all they way back in the RF stage. Of course, that noise level is way below the band noise even up on 10 meters, so it's not limiting the sensitivity of the receiver. But with the RF and AF gain controls at minimum, so I'll I'd hear is the noise from the audio amplifier, my K2 is completely quiet. Ron AC7AC _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
