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<DIV>I use BC640 PNP switches, you might cross check the max limits of the 2N907
against these. </DIV>
<DIV> </DIV>
<DIV>I use 3k3 buss resistors in the Penny DB25 line and 2k2 in the supply to
base for same reason as Phil suggested.</DIV>
<DIV>It should be a compact layout on Vero or perf board. Make sure the supply
properly decoulped to avoid modulating the switch lines.</DIV>
<DIV> </DIV>
<DIV>Shel CT1IZU</DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>----- Original Message ----- </DIV>
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<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=k1jj@comcast.net href="mailto:k1jj@comcast.net">Tom Cathey</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=hpsdr@lists.openhpsdr.org
href="mailto:hpsdr@lists.openhpsdr.org">hpsdr@lists.openhpsdr.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, March 04, 2011 2:21
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [hpsdr] Control an FT-1000D
Low Pass Filter assembly with PSDRmouse?</DIV>
<DIV><BR></DIV>***** High Performance Software Defined Radio Discussion List
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<DIV dir=ltr align=left><SPAN class=796131102-04032011>Thanks for the info,
Joe and Phil.</SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=796131102-04032011></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=796131102-04032011>Yes, I need 9V high
switched to the relays at 100 ma per band. The relays are grounded on
the board. I see the connections coming off the Penny 25 pin
connector on the schematic. Also see the software toggles required.
Good.</SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=796131102-04032011></SPAN><SPAN
class=796131102-04032011></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=796131102-04032011>That circuit looks
good, Joe. Though after a quick look, the M54581 chip is $20 and only
available from the UK. </SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=796131102-04032011></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=796131102-04032011>I was
thinking an easier way might be to use a small 2N2907 PNP
transistor which gets its base grounded from Penny, the collector to 9V and
the emitter in series with the LP relay. I would need one transistor per
band, or about seven transistors total. Not too bad. </SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=796131102-04032011></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=796131102-04032011>Does this sound like it
would work OK?</SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=796131102-04032011></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=796131102-04032011></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=796131102-04032011>Tom, K1JJ</SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=796131102-04032011></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=796131102-04032011></SPAN> </DIV>
<DIV dir=ltr align=left>
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