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I ran 6m/2m voice diplexed to a common antenna for 25 years in the
car.<br>
<br>
The antenna was a 2m 5/8. There are two ways to *tune* a 5/8 on 2m.
One is to use a tuned circuit as seen in ARRL publications. The
other (used commercially in Oz) is to add a series loading coil at
the base so the antenna appears electrically to be 3/4 wavelength -
a good match to 50 ohm coax. There is little radiation from the coil
- typically 6 turns of 18# wound over 1.5".<br>
<br>
That same antenna is close enough to resonance on 6m that any
reactance can be removed with a tuneable diplexer. My homebrew
diplexer used a band pass and a band reject circuit in each leg.
Opposite band rejection was >60dB and insertion loss <1dB. It
didn't look pretty, in its cut-down metal ice cream can, but it
worked a treat. A later version was manufactured from double-sided
PC board, soldered up as a box.<br>
<br>
Ray vk2tv<br>
<br>
<br>
On 01/03/11 08:08, Wes Johnston, AI4PX wrote:
<blockquote
cite="mid:AANLkTi=j9SwO+xuyLk2Vc5vgqVaBzw3HLXtUzoooDHGV@mail.gmail.com"
type="cite">
<div>Just to throw another fish in the kettle, you can run 9k6 on
6m. (>50mhz) . Back in the 70's in a magazine I read,
there was a such thing as a 6m/2m dual band antenna.</div>
<div><br clear="all">
Wes </div>
<div>---</div>
<div>"Language shapes the way we think, and determines what we can
think about." -- B. L. Whorf</div>
<br>
<br>
<br>
<div class="gmail_quote">On Mon, Feb 28, 2011 at 16:01, Tom <span
dir="ltr"><<a moz-do-not-send="true"
href="mailto:nineback@gmail.com">nineback@gmail.com</a>></span>
wrote:<br>
<blockquote style="border-left: 1px solid rgb(204, 204, 204);
margin: 0px 0px 0px 0.8ex; padding-left: 1ex;"
class="gmail_quote">
<div>This is what we need to figure out. No more loss of
audio on 2 meters.</div>
<div> </div>
<font color="#888888">
<div>Tom<br>
<br>
</div>
</font>
<div class="gmail_quote">
<div class="im">---------- Forwarded message ----------<br>
From: <b class="gmail_sendername">Bob Bruninga</b> <span
dir="ltr"><<a moz-do-not-send="true"
href="mailto:bruninga@usna.edu" target="_blank">bruninga@usna.edu</a>></span><br>
Date: Mon, Feb 28, 2011 at 1:00 PM<br>
Subject: Re: [aprssig] 9600 APRS<br>
</div>
<div class="im">To: TAPR APRS Mailing List <<a
moz-do-not-send="true" href="mailto:aprssig@tapr.org"
target="_blank">aprssig@tapr.org</a>>, <a
moz-do-not-send="true"
href="mailto:earl.kd5xb@gmail.com" target="_blank">earl.kd5xb@gmail.com</a><br>
<br>
<br>
My personal goal is to change my voice operations habits
to UHF repeaters<br>
(I'm tired of the same'o-same-o on the local 2m one
anyway). Its amazing to<br>
see the 2m APRS keep working even while I am talking, and
not lose syllables<br>
whenever my packet goes out. Bob, WB4APR<br>
<br>
<br>
</div>
<div class="im">_______________________________________________<br>
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target="_blank">aprssig@tapr.org</a><br>
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href="https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig"
target="_blank">https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig</a><br>
<br>
<br>
<br>
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href="https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig"
target="_blank">https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig</a><br>
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<br>
</blockquote>
</div>
<br>
<pre wrap="">
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</pre>
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