Jeff, fascinating. I tried it here also and indeed the hump is all but gone using the RS 270-054 on line-in. Now I always thought that only a high spec audio isolator (as in handles way above audible frequencies well) would work on the input given the I/Q spectrum is about 90kHz wide at a sampling rate of 96kb/s (I am using the Delta-44). But I closely compared the panadapter with and without the isolator and I see no difference other than the DC hump. What am I missing?
73 de Joe - AB1DO ----- Original Message ----- From: "Jeff Anderson" <[EMAIL PROTECTED]> To: <FlexRadio@flex-radio.biz> Sent: Monday, January 22, 2007 18:18 Subject: Re: [Flexradio] spam: Spur on AM > Unfortunately I seem to have deleted the appropriate message, but I want > to > thank whoever recommended the idea of eliminating the displayed "IF hump" > by > putting the ground-loop isolator in the Line-In path. What a brilliant > idea - it works wonderfully. Many thanks!! > > With my Delta 44 the hump is down about 20 dB, and is now (when viewed at > 7 > MHz) at a level lower than my usual "ambient" noise level when an antenna > is > connected. > > Thanks again! > > - Jeff, K6JCA > > (Note: if you purchase the Radio Shack unit (SKU 270-054), you'll also > need > to purchase an additional adapter cable (female stereo 3/8" jack to dual > RCA > plugs, if I recall correctly).) > > > _______________________________________________ > FlexRadio mailing list > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > FlexRadio Homepage: http://www.flex-radio.com/ > > FlexRadio Knowledge Base: http://kb.flex-radio.com/ _______________________________________________ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com/ FlexRadio Knowledge Base: http://kb.flex-radio.com/
