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Yes. That's how simulcast systems work.<br><br>When you base your syncronization on a GPSDO (GPS Disciplined Oscillator)<br>such as the Trimble Thunderbolt (which has accuracy typically of 10-20 parts<br>per TRILLION, which means that if you were transmitting at 1GHz, you would<br>be no more then 0.010 to 0.020 Hz off) *and* the audio is in sync with that timing<br>source *and* the deviation is set consistently accurately between all transmitters,<br>then, yes, its quite possible.<br><br>Obviously, you need to use transmitters appropriately suited for this type of application,<br>which either by initial design or by modification, allow injection of an external (to the<br>transmitter) reference frequency. Some transmitters are designed with this in mind.<br>Others can be trivially modified to allow this.<br><br>For example, the Trimble Thunderbolt has its precise frequency output at 10 MHz.<br>Some transmitters will operate directly from the frequency reference. Others need<br>some other frequency. If this is the case, a clock generator (locked to the Thunderbolt's<br>10 Mhz output) that produces the appropriate frequency is needed.<br><br>Some radio manufacturers, such as the one that Pete Elke (WI6H) was referring to<br>make devices specifically suited for this purpose (he was using the clock generator<br>within a high stability oscillator unit from an old Motorola paging transmitter).<br><br>Another option would be to use the PCGM (Programmable Clock Generator Module) that<br>Mark at Micro-Node (K7IZA) is coming out with soon. It takes the 10 MHz input from the<br>Trimble Thunderbolt, and generates pretty much whatever reference frequency you<br>"tell it to" (from 6-200 MHz), and also, acts as a power supply for the Trimble Thunderbolt.<br><br>The reason I keep making specific reference to the Trimble Thunderbolt is because they are<br>readily available on the surplus market (rather inexpensively), and are EXTEREMELY well-suited<br>for this application (probably the best selection given all of the parameters involved here).<br><br>JIM WB6NIL<br><br><div><div id="SkyDrivePlaceholder"></div>> Date: Thu, 22 Dec 2011 12:41:11 +0200<br>> From: shaun@pmbnet.co.za<br>> To: app_rpt-users@ohnosec.org; zs5bg@harc.org.za; zs5z@harc.org.za<br>> Subject: [App_rpt-users] RADIO THIN CLIENT MODULE and "Simulcast Transmit System"<br>> <br>> Before I break open my kid's piggy-bank for a couple of "ALLSTAR RTCM <br>> (RADIO THIN CLIENT MODULE)'s " http://micro-node.com/thin-m1.html<br>> I need an important question answered. .............please?<br>> <br>> If both rptr's are in the same coverage area, and transmit at the same <br>> time on the same freq, BUT perfectly in sync using the GPS sync <br>> option...................... will the end user (client/club member) hear <br>> a perfect signal? (even if he/she where in range of both transmitters?)<br>> One would think you would hear a heterodyne of some sort with both <br>> signals reaching and mixing into the users transceiver.<br>> <br>> We all know that if 2 hams try use their local repeater at the same time <br>> (doubling) then the end result is Yucky, unless the one users tx signal <br>> is much stronger than the other user.<br>> <br>> Is this RTCM system so accurate, that the user hears a perfectly synced <br>> and clear signal?<br>> <br>> Shaun<br>> zr5s<br>> <br>> <br>> <br>> <br>> <br>> <br>> <br>> <br>> <br>> <br>> _______________________________________________<br>> App_rpt-users mailing list<br>> App_rpt-users@ohnosec.org<br>> http://ohnosec.org/cgi-bin/mailman/listinfo/app_rpt-users<br></div> </div></body>
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