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<a class="moz-txt-link-abbreviated" href="mailto:AA3JY@Winlink.org">AA3JY@Winlink.org</a> wrote:
<blockquote cite="mid5BP6X4ONBEMQ@SanDiego.winlink.org" type="cite">
<blockquote type="cite">
<pre wrap="">What I don't like about integrated GPS receivers is that you still have to
connect an external antenna...
</pre>
</blockquote>
<pre wrap=""><!---->
Look at Garmin's Rino 520 and 530....
Regards,
Clay AA3JY
(via WL2K
</pre>
</blockquote>
But that's a *hand held* where the radio is going to probably be
outdoors. It would be useless to do that with a mobile rig like a D700
where the radio chassis is inside the trunk or under a seat. <br>
<br>
<br>
The external GPS antennas used with built-in GPS receivers normally
contain 15-20 dB gain preamps to offset the horrendous loss of
small-gauge coax at 1575 MHz where GPS operates. In turn, there is
virtually no selectivity in front of these high-gain amplifiers -- the
antenna element is a very broadband patch that is not sharply
resonant. These amplifiers often overload and block every time you
get within a few blocks of a 1900 MHz PCS cell site, causing the GPS
reception to drop out every time you get near one. <br>
<br>
The combined receiver/antenna puck-type GPS devices don't use active
pre-amplified antennas because the ant is connected directly to the
receiver with no coax at all. <br>
<br>
In real life testing in RF-saturated areas like Los Angeles or Chicago,
I have seen the inexpensive GPS18 or Deluo GPSes sitting on the
dashboard inside a car far outperform expensive two-piece
"professional" units with roof-mounted active antennas. <br>
<br>
Further, a root-mounted GPS active GPS antenna will often overload,
block, and knock the GPS out of lock every time your own 25-50W two
meter or UHF rig keys up, if the antennas aren't separated far
enough. This usually isn't a problem on a ship or aircraft where the
antennas can be farther apart, but is often a problem on cars. <br>
<br>
The "hockey puck" all-in-one GPS sitting on the dash UNDER the roof of
the car will experience far less RF from your other transmitters. <br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
Stephen H. Smith wa8lmf (at) aol.com <br>
EchoLink Node: 14400 [Think bottom of the 2M band]<br>
Home Page: <a class="moz-txt-link-freetext" href="http://wa8lmf.com">http://wa8lmf.com</a><br>
<br>
NEW! UI-View Misc Notes and FAQ<br>
<a class="moz-txt-link-freetext" href="http://webs.lanset.com/wa8lmf/aprs/UIview_Notes.htm">http://webs.lanset.com/wa8lmf/aprs/UIview_Notes.htm</a> <br>
<br>
"APRS 101" Explanation of APRS Path Selection & Digipeating <br>
<a class="moz-txt-link-freetext" href="http://webs.lanset.com/wa8lmf/DigiPaths">http://webs.lanset.com/wa8lmf/DigiPaths</a> <br>
<br>
Updated "Rev G" APRS <a class="moz-txt-link-freetext" href="http://webs.lanset.com/wa8lmf/aprs">http://webs.lanset.com/wa8lmf/aprs</a><br>
Symbols Set for UI-View, <br>
UIpoint and APRSplus:<br>
<br>
<br>
<br>
<br>
<br>
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