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<a class="moz-txt-link-abbreviated" href="mailto:aprssig.kd5uzz@spamgourmet.com">aprssig.kd5uzz@spamgourmet.com</a> wrote:
<blockquote cite="mid6677c01005050321326a71d99e@mail.gmail.com" type="cite">
<pre wrap="">Has anyone here built a mic-e enabled voice repeater? I'm unable to
find any information with Google. My understanding is that you
basically fool the repeater controller into thinking the user has
stopped transmitting whenever a TNC detects a packet (simple OR gate
with Rcvr COR and TNC decode signal?). Any suggestions on what TNC I
should use? I'm guessing the easiest thing would be to have a TNC that
lights an LED while it decodes a packet. Will I need an audio delay
circuit in the controller? Thanks!
</pre>
</blockquote>
<font face="Arial">A search for "Mic-E Repeater" on Google netted this
page in about 2 seconds:<br>
<a class="moz-txt-link-freetext" href="http://wes.johnston.net/aprs/aprs5a.htm">http://wes.johnston.net/aprs/aprs5a.htm</a> <br>
<br>
Basically any TNC with a DCD indicator can be used to briefly mute the
repeat audio during packet bursts. The trick is that you must use true
software DCD so that the DCD doesn't false trigger on voice peaks,
touch-tone bursts, etc. (Watch how frequently, the simple hardware
energy-detect DCD on a TNC-2, MFJ, etc falses on voice peaks, squelch
crashes, etc.) False DCDs muting the repeat audio will keep punching
holes and "hiccups" into voice transmissions.<br>
<br>
The majority of Mic-E systems are built using KPC3s because they can be
set for true software DCD (i.e. run open squelch), unlike most
others. Normally the RX side of the KPC3 is wired across the repeater
receiver audio while the TX side is connected to a transceiver on
144.39. The CD OUTPUT pin of the KPC3 is used to mute repeat audio
during the packet. In turn, the squelch line of the 144.39 receiver
is connected to the EXTERNAL CD INPUT of the KPC3 in order to prevent
the TNC from keying up on 144.39 until the channel is clear. <br>
<br>
This is all assuming you want to prevent packet bursts from being
retransmitted by the repeater. If you are willing to let packets pass
through the repeater, a receiver tuned to the repeater output, a
transceiver on 144.39 and a TNC can be setup anywhere within
full-quieting range of the repeater to do the same thing. <br>
<br>
[ I am currently doing this here in southern California. I am
monitoring the 146.700 Sunset Ridge repeater with a dedicated
crystal-controlled receiver (the RX from a commercial VHF repeater
actually) from about 20 miles away. Any packets repeated by this sytem
are decoded here at my house, retransmitted on 144.39 and also gated to
the Internet. ]<br>
<br>
<br>
Stephen H. Smith wa8lmf (at) aol.com <br>
<br>
Home Page: <a class="moz-txt-link-freetext" href="http://wa8lmf.com">http://wa8lmf.com</a><br>
<br>
New APRS Symbol Chart <br>
<a class="moz-txt-link-freetext" href="http://webs.lanset.com/wa8lmf/miscinfo/APRS_Symbol_Chart.pdf">http://webs.lanset.com/wa8lmf/miscinfo/APRS_Symbol_Chart.pdf</a> <br>
<br>
New/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>
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