Phil Try designing a pico Amp reading Electrometer and see how much hair PS noise eliminates!
I "put my trust in Duracell" hi hi. Phil, K3IB ----- Original Message ----- From: "philip gentile" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; <[email protected]> Sent: Tuesday, August 15, 2006 10:33 AM Subject: Re: [Flexradio] Spurs and Picket Fences > i'm just guessing here, but could all these spurs and fences and such be > caused by power supply noise from the external switching or ripple from > linear power supplies? > > if the PSSR of the linear stuff is low enough or the noise high enough, it > falls within the signal dynamic range and power supply noise becomes signal. > > a lot of switchers develop a real nice wideband sinX/X noise power > distribution above the fundamental. if the noise or ripple is within the > passband of the dsp stuff it can be hard to filter out. > > in my experience of running analog into high speed analog processing > hardware is generally met with disaster after the A to D converters unless i > have extremely clean supplies from DC to well past the PS switching and > signal frequencies on the analog side. switching power supplies tend to send > noise straight through the whole circuit. > > just my 2 cents! > > phil AB2JL _______________________________________________ FlexRadio mailing list [email protected] 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
