>At 09:57 AM 10/2/04, Wade - KR7K wrote: > > >As long as you are using 1 antenna system for TX and another antenna system > >for RX then that will work without a duplexer, if you follow a few > >guidelines. First, you have to use gain antennas (not 1/4 waves verticals). > >Unity gain, omni-directional antennas (like 1/4 wave verticals) radiate in > >all directions equally and you cannot effectively isolate one from the > >other.
Actually, the 1/4 wave ground plane antenna doesn't radiate in all directions equally. Instead it has quite a hole in the pattern directly above the vertical radiator and they work quite when they're stacked one above the other, vertically, using the top antenna for receive and mounting it upside down. Separation should be as much as you can stand but at least 30 feet. They've been used on repeaters for years. I've run several repeaters without a duplexer using 1/4 wave ground planes myself. 73, Tony W4ZT >Provided you have 2 antennas with some gain, I would recommend at > >least 9dBi, you will need enough tower or mast to vertically seperate the > >antennas by 10 or 15 feet. If you are using yagi type antennas, the same > >rules apply. > > > >Good luck > > > >Wade - KR7K > > > > > >----- Original Message ----- > >From: "Dakota Summerhawk" <[EMAIL PROTECTED]> > >To: <[email protected]> > >Sent: Friday, October 01, 2004 5:50 PM > >Subject: [Repeater-Builder] Does the R100 need duplexer if using two > >anetnnas? > > > > > > > > > > > > > I have a UHF R100 and need to know if I need a duplexer if I am going to > > > be using two antennas. Can someone help? > > > Thanks > > > Dakota 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/
