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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>From my understanding, #1 is radio dependant. Although it
would be a great design rule, I recall one of the versions (or all) of the Icom
756/746’s did NOT ground the RX antenna port when it was
implemented. I may be wrong, but I remember something about a
modification for this.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Assuming the majority of the separate RX antennas would be for a
Beverage or directional loop, Pat implements a simple coax switch. 1
input into the radio, 2 beverages in use, NW, NE. Switch to the one that
hears the station the best.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Band decoders, if used to drive off the shelf devices (the 6pack
and RatPack come to mind) would probably be a bit overkill for RX’ing
antenna’s, unless you’re implementing a ton of them. Besides rx
antennas on the low bands, where else would you use a separate RX antenna from
your TX antenna? Maybe diversity? Directionality or stacking of
course could be obtained with stack matches, 6packs/rat packs, etc.
Additionally, you’ll have to contend with driving the additional decoder,
either from the rig itself, a CIV command from the computer interface, or the
software (LPT or Serial port). Some things don’t like multiple
devices connected to it.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
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color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
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<p class=MsoNormal><b><span style='font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-family:"Tahoma","sans-serif"'> lcc-bounces@louisianacontestclub.org
[mailto:lcc-bounces@louisianacontestclub.org] <b>On Behalf Of </b>Scott
Dickson, W5WZ<br>
<b>Sent:</b> Thursday, August 06, 2009 10:37 PM<br>
<b>To:</b> lcc@louisianacontestclub.org<br>
<b>Subject:</b> [LCC] Receive antenna switching - Rhyme and reason...<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span style='font-family:"Arial","sans-serif"'>Hi
guys! <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-family:"Arial","sans-serif"'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-family:"Arial","sans-serif"'>It is time
for me to add receive-only antenna switching to my thought process as I
continue planning and building. A few questions in my mind:<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-family:"Arial","sans-serif"'><o:p> </o:p></span></p>
<ol style='margin-top:0in' start=1 type=1>
<li class=MsoNormal style='mso-list:l1 level1 lfo3'><span style='font-family:
"Arial","sans-serif"'>Is it necessary to ground the receive-only antenna
(or receive-only antenna port on the XCVR) during same band transmit on
any rig in the shack? I’ve heard that some rigs only mute the
receive-only antenna port, while the RF still hits the front end of the
receiver. What method are you using?<o:p></o:p></span></li>
<li class=MsoNormal style='mso-list:l1 level1 lfo3'><span style='font-family:
"Arial","sans-serif"'>What method/device(s) are you using to switch between
multiple receive antenna, shared between 2 transceivers?<o:p></o:p></span></li>
<li class=MsoNormal style='mso-list:l1 level1 lfo3'><span style='font-family:
"Arial","sans-serif"'>Are any of the RF switching devices automated, i.e.
using a band decoder to drive switching?<o:p></o:p></span></li>
</ol>
<p class=MsoNormal><span style='font-family:"Arial","sans-serif"'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-family:"Arial","sans-serif"'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-family:"Arial","sans-serif"'>I’m
still working diligently on the station here at W5WZ. If you are
interested in the progress, please visit my journal page:<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-family:"Arial","sans-serif"'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-family:"Arial","sans-serif"'><a
href="http://w5wz.com/main/page_my_journal.html">http://w5wz.com/main/page_my_journal.html</a><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-family:"Arial","sans-serif"'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-family:"Arial","sans-serif"'>--Scott, W5WZ<o:p></o:p></span></p>
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