Everyone who voiced an opinion.....
I see the error of my ways! I shall use only (1) antenna! Just want to rec. a better signal from a 800 trunking transmitter, about 30 mi. distant. Thanks guys, for setting me straight! Best Regards, Tim Hardy W7TRH/AFA0TP Vashon Is. Wa. ----- Original Message ----- From: "Jeff DePolo" <[email protected]> To: [email protected] Sent: Wednesday, March 10, 2010 10:50:38 AM GMT -08:00 US/Canada Pacific Subject: RE: [Repeater-Builder] Antenna Phasing Question > I have three (3) Antel [BCD 80010] 806-900 mHz vertical > antennae that I would like to mount on the three legs of my > tower for omni pattern (Rec. only). Several questions come to mind. > > 1.) At the rated frequency, how many inches should the side > arm place the ant. from the tower? > > 2.)What would be the best way to phase the antennae? I have a > Andrews three port "Splitter", and will use "LDF4-50A for > feedline. I would suspect the length of the pigtail from each > antenna to splitter is going to be critical.......or not, for > receive only? Any time you start to try to phase omni antennas like you're describing, you're going to end up with nothing like the "omni" pattern you're hoping to achieve. You'll have deep nulls all over the place, it's just a bad idea. If you were willing to run the three antennas to three separate feedlines and feed three separate receivers and vote between them, that would make more sense, but passively combining the three antennas into one feedline is going to yield extremely disappointing results. You're better off with a single omni and eating whatever tower nulls you end up with... > BTW......How good of an antenna is the "Antel" BCD 80010? I'm using a BCD87010, which is the 870-960 MHz 10 dBd omni with the standard 1.25 degrees of downtilt on a ham repeater in Philly. It works well and is built well. Bought it from Tessco a few years ago. Receive performance is impaired by all of the Part 15 junk, but that's not the fault of the antenna. The BCD800 series is 806-900 MHz; I don't think I'd want to use it in the ham band if that's your intention, I'd get an 870 series. --- Jeff WN3A
