OK, too much interperatation based on a lack of information. For 2 antennas you need vertical seperation (best) or horizantal seperation (very large), or 2 bandpass filters, one for each transceiver.
Easiest solution, if you have the vertical real estate, use at least 25-30 ft seperation (preferably 40-50ft) between the antennas. I prefer to use top of lower antenna to bottom of top antenna as the measurement of distance. Charts often say "center of antenna radiation". Horizontal seperation would require 300' for the same amount of isolation. Next best is a lesser amount of vertical seperation, coupled with bandpass cavities. See http://www.repeater-builder.com/antenna/separation.html I would suggest that you find a local elmer to assist you. Milt N3LTQ ----- Original Message ----- From: "Kc7hgn" <[email protected]> To: <[email protected]> Sent: Tuesday, July 20, 2010 5:59 AM Subject: [Repeater-Builder] Re: Duplxer, tuned cavity question. > Well they don't have to be on the same antenna. But each one would be > about 25 feet from each other. Both Copper J-Pole antennas. I guess I > would still need to buy a duplexer. Could I build one? Will be 50w on 1 > antenna and 25 on the other. I don't know much about this stuff. > Thanks, Kevin > Kc7hgn > > --- In [email protected], Joe <k1ike_m...@...> wrote: >> >> Good advice. >> >> The only thing that I would add is that you need to use good quality >> equipment for the antenna system. This includes the duplexer, jumpers, >> connectors, cable and antenna. When you have a situation where two >> transmitters can be on the air at the same time on the same antenna >> system, you always stand the chance of creating intermod. >> >> 73, Joe, K1ike >> >> On 7/19/2010 6:55 AM, Milt wrote: >> > Assuming from reading between the lines that you want to use both >> > stations >> > on the same antenna, get a 2 meter duplexer. The seperation between >> > the 2 >> > frequencies is 0.64 MHz. At bare minimum you need a notch (reject) >> > duplexer >> > but a bandpass-band reject type would probably be the better choice. >> > Tune >> > each leg to the respective frequency and connect to the respective >> > radio. >> > >> > Milt >> > N3LTQ >> > >> > >> > ----- Original Message ----- >> > From: "Kc7hgn"<kc7...@...> >> > To:<[email protected]> >> > Sent: Monday, July 19, 2010 5:48 AM >> > Subject: [Repeater-Builder] Duplxer, tuned cavity question. >> > >> > >> > >> >> I have an APRS station on 144.39. I would also like to run my Packet >> >> station on 145.03. So I need someway to run both stations. What would >> >> I >> >> need to do? Can I build what I would need? If so where would I find >> >> that >> >> info? >> >> Thanks, Kevin >> >> Kc7hgn >> >> >> >> >> >> >> >> ------------------------------------ >> >> >> >> >> >> >> >> Yahoo! Groups Links >> >> >> >> >> >> >> >> >> > > > > > ------------------------------------ > > > > Yahoo! Groups Links > > >
