Gary, Duplexer of choice for me is the Sinclair Q2330E. I have had very good results with these on our 75 Watt VHF Micor stations and we use a Angle Linear preamp on the receivers.
In your situation where you have a brand new Telewave, I would be tempted to call up Telewave and order 2 more cavities and the necessary pieces to turn your TPRD1554 into a TPRD1556. I don't think you will be disappointed with the end results. The second alternative is to get your hands on one or two of the older 12" Motorola or GE pass cans and insert them between the duplexer and the receiver and transmitter. To answer your question, the difference between 77db and 90-100db of isolation is like night and day, especially if you are using a preamp on the receiver and are running 25 watts or more power with the transmitter. If your receiver has a good tight helical coil front end, sometimes you can get by with a little less duplexer if everything else is perfect. I also can not stress enough to use Heliax for your feedline and also for your interconnect cables if possible. I use Andrew LDF for the feedline and Andrew FSJ superflex for all the interconnect jumpers. If you do need flexible jumpers made out of coax, use the silver plated double shielded cable with silver plated connectors. As has been said here many times over, whatever you do, please save your self a lot of trouble and greif and do not use any LMR cable for anything near a repeater or duplexer. Joe - WA7JAW --- In Repeater-Builder@yahoogroups.com, "garyp609" <[EMAIL PROTECTED]> wrote: > > What duplexer would you recommend? I was expecting better results. Is > there a huge difference in 77db versus 100db isolation besides the > price? Performance wise. Kinda wish I would have done my homework > before buying the TPRD1554. Running 25 watts here. What is your > duplexer of choice? > Thanks & 73's Gary > >
