> -----Original Message----- > From: [email protected] [mailto:elecraft- > [email protected]] On Behalf Of wayne burdick > Sent: Friday, January 09, 2009 8:53 PM > To: Dave Yarnes > Cc: [email protected] > Subject: Re: [Elecraft] Using K3's Pre-amp > > The noise floor is your entire problem :) It's a fact that the preamp > improves the MDS of the K3 by at least several dB. But if your noise > floor is S4, it will do not good at all, because all lower signals are > already masked by the noise.
I just ran a noise experiment at my QTH yesterday. My typical noise is s7.0 S6.5 s7.5 on 80m, 40m & 20m respectively. With every circuit in the house off, except the one the radio is on, and with only the power supply and the radio on that one circuit the noise is s4.0 S4.75 s5.0. I turned on circuits one at a time and recorded to S level jump for each. The 'home entertainment center' seems to be the biggest contributor so I'll start there. Now I just need to figure out how the switch off the neighborhood transformers and silence my neighbors! :) I have some fairly large power lines across the street. Are they usually strong contributors to noise? You can see the resulting data here: http://www.ka7ark.com/20080111QTHnoise/pics.html Adam - ka7ark _______________________________________________ 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
