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<DIV>Switching power supplies when underloaded quite often present lower then normal voltages. Try a 20 ohm power resister on the 5 volt line and remeasure. This resister should be a 5 watt value. The Atlas board has a spot for just this.</DIV>
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<DIV>Brian K3PU<BR><BR><BR><BR>Jan 29, 2009 09:01:30 AM, <A class=parsedEmail href="mailto:ke9h@austin.rr.com" target=_blank>ke9h@austin.rr.com</A> wrote:<BR></DIV>
<BLOCKQUOTE style="BORDER-LEFT: rgb(102,153,204) 3px solid">***** High Performance Software Defined Radio Discussion List *****<BR><BR>Don:<BR><BR>The power supplies should be within 5 percent of the target voltage and<BR>reasonably quiet, with respect to ripple, and switching noise if you are using<BR>switching power supplies. I don't have a spec on "reasonably quiet", but<BR>I would guess something like, less than 50 milliVolts at audio frequencies<BR>and down, and a lot less than that at higher frequencies. Otherwise, you will<BR>get birdies up and down the receiver at harmonics of the switching frequencies.<BR><BR>You really don't need -12 V, since it only powers a serial port on Ozy that<BR>is not currently being used.<BR><BR>+12 and +5 is all that you need for running Ozy/Penelope/Mercury in the<BR>current configuration.<BR><BR>--- Graham / KE9H<BR><BR>==<BR>---- Don Latham <<A class="parsedEmail parsedEmail" href="mailto:djl@montana.com" target=_blank>djl@montana.com</A>> wrote: <BR>> ***** High Performance Software Defined Radio Discussion List *****<BR>> <BR>> OK, I built the Atlas backbone. Put on 3 different power supplies. All<BR>> read funny on +12 from 10 to 11.5 volts, on -12 all read about -10 volts.<BR>> Typical? Will these ps's do the job?<BR>> Thanks for helping someone too lazy to look in the archives...<BR>> <BR>> <BR>> -- <BR>> Dr. Don Latham AJ7LL<BR>> Six Mile Systems LLP<BR>> 17850 Six Mile Road<BR>> POB 134<BR>> Huson, MT, 59846<BR>> VOX 406-626-4304<BR>> <A class=parsedLink href="http://www.lightningforensics.com" target=_blank>www.lightningforensics.com</A><BR>> <A class=parsedLink href="http://www.sixmilesystems.com" target=_blank>www.sixmilesystems.com</A><BR>> <BR>> _______________________________________________<BR>> HPSDR Discussion List<BR>> To post msg: <A class="parsedEmail parsedEmail" href="mailto:hpsdr@hpsdr.org" target=_blank>hpsdr@hpsdr.org</A><BR>> Subscription help: <A class=parsedLink href="http://lists.hpsdr.org/listinfo.cgi/hpsdr-hpsdr.org" target=_blank>http://lists.hpsdr.org/listinfo.cgi/hpsdr-hpsdr.org</A><BR>> HPSDR web page: <A class=parsedLink href="http://hpsdr.org" target=_blank>http://hpsdr.org</A><BR>> Archives: <A class=parsedLink href="http://lists.hpsdr.org/pipermail/hpsdr-hpsdr.org/" target=_blank>http://lists.hpsdr.org/pipermail/hpsdr-hpsdr.org/</A><BR><BR>_______________________________________________<BR>HPSDR Discussion List<BR>To post msg: <A class="parsedEmail parsedEmail" href="mailto:hpsdr@hpsdr.org" target=_blank>hpsdr@hpsdr.org</A><BR>Subscription help: <A class=parsedLink href="http://lists.hpsdr.org/listinfo.cgi/hpsdr-hpsdr.org" target=_blank>http://lists.hpsdr.org/listinfo.cgi/hpsdr-hpsdr.org</A><BR>HPSDR web page: <A class=parsedLink href="http://hpsdr.org" target=_blank>http://hpsdr.org</A><BR>Archives: <A class=parsedLink href="http://lists.hpsdr.org/pipermail/hpsdr-hpsdr.org/" target=_blank>http://lists.hpsdr.org/pipermail/hpsdr-hpsdr.org/</A><BR></BLOCKQUOTE></BODY></html>
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