You may want to search Prodel Ecos This Italian system is the best I have heard in the working enviroment.
Two methods -landline with high stability chrystal ovens or the GPS method.Later wins hands down. Regards Bardley Glen --- Mike Morris <[EMAIL PROTECTED]> wrote: > At 05:22 PM 6/4/05, you wrote: > > > >Has anyone implemented a simulcast (multiple TX's > on the same channel) system > >for a ham 440 repeater system? It looks like you > have to have TXCO's capable > >of tracking within a few hertz of each other. > > > >You can't do this with standard TCXO's, so I'm > wondering if anyone has tried > >modifying a TCXO to lock to a GPS source, or NTP > source. > > > >Steve WA6ZFT > > Years ago a group here in L.A. did the R&D and > actually > breadboarded the hardware and had a couple of > exciters > running. > > The impetus was finding 25 Panasonic color TVs that > ran > on +12v (made for RVs) in the city dump that has > smashed > picture tubes. > > They added a PLL to determine if the TV's color > burst > oscillator was locked to the off-the air signal. > This lock > signal was used to select F1 vs F2 on the exciter. > F1 had > a regular channel element, F2 had the output of the > synthesizer. The synthesizer was designed around > using > the TV color burst crystal as it's reference > oscillator, and > output a sine wave signal into a channel element > that was > modified to be a simple signal buffer (hint: the > hole in the > element cover fits one manufacturer's SMA connector > just > fine). > > The system never got built - the group was getting > free > rent at six prime privately owned sites (in exchange > for > site management and maintenance duties) and the > owner > sold out while the selling was good, and the sites > went > from zero to $250 a month. > > I have no info on the hardware design, the engineer > that was > doing the work died from emphysema a while back.... > his > smoking caught up with him. > > Mike WA6ILQ > > > > > > > Yahoo! Groups Links > > > [EMAIL PROTECTED] > > > > > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
