Re: [Repeater-Builder] Multiple receivers on one antenna
On 5/5/2010 4:34 PM, wd5etd wrote: > Sorry for the dumb question but, I have a group trying to add a link > at one site for 5 repeaters. They are not trunked. What is the > cheapest way for them to share 1 antenna? They have a very good DB > antenna but, I did not think it necessary for them to buy 5! > > They are out in the country quite a ways. So, there is not much else > to interfere. > > I know a combiner is probably the usual way but, I thought there > might be a cheaper way since it is only for receive. > > They do not have a tower for the receive antenna but, they do have a > multi-story building. So, feed line expense is not a concern if they > use multiple antennas. > > Thanks > > Rick As others mentioned, what you want is receive multicoupler. However, I do NOT recommend using any kind of TV/CATV amp on it, since they are designed for 75 ohm, and can become unstable in a 50 ohm system. I have seen this personally on a multi-channel UHF repeater system where that was done, with a UHF TV amp and one or two cavities were used with a regular TV type splitter. It was a constant battle keeping it running. Anytime the temperature changed more than 20 degrees, someone had to go out and either retune the cavities, or adjust the gain on the amps to keep it out of oscillation (usually both). Just about any of the larger antenna mfg's make rx multicouplers, as well as others. Just make sure it's a 50 ohm system, designed for LMR use, and not something someone might use in their house. Jim
Re: [Repeater-Builder] Multiple receivers on one antenna
On Wed, 5 May 2010, wd5etd wrote: > Sorry for the dumb question but, I have a group trying to add a link > at one site for 5 repeaters. They are not trunked. What is the > cheapest way for them to share 1 antenna? They have a very good DB > antenna but, I did not think it necessary for them to buy 5! > > They are out in the country quite a ways. So, there is not much else > to interfere. > > I know a combiner is probably the usual way but, I thought there might > be a cheaper way since it is only for receive. > > They do not have a tower for the receive antenna but, they do have a > multi-story building. So, feed line expense is not a concern if they > use multiple antennas. Cheapest way would be a band-pass cavity ahead of a cable TV distribution amp and a multi-port hybrid splitter. This assumes that the antenna isn't duplexed and used for transmitting as well nor are any of the transmit frequencies within the receive bandwidth. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Multiple receivers on one antenna
The device you want is a receiver multicoupler. Plus appropriate filtering ahead of it. Matthew Kaufman wd5etd wrote: > Sorry for the dumb question but, I have a group trying to add a link at one > site for 5 repeaters. They are not trunked. What is the cheapest way for > them to share 1 antenna? They have a very good DB antenna but, I did not > think it necessary for them to buy 5! > > They are out in the country quite a ways. So, there is not much else to > interfere. > > I know a combiner is probably the usual way but, I thought there might be a > cheaper way since it is only for receive. > > They do not have a tower for the receive antenna but, they do have a > multi-story building. So, feed line expense is not a concern if they use > multiple antennas. > > Thanks > > Rick >
[Repeater-Builder] Multiple receivers on one antenna
Sorry for the dumb question but, I have a group trying to add a link at one site for 5 repeaters. They are not trunked. What is the cheapest way for them to share 1 antenna? They have a very good DB antenna but, I did not think it necessary for them to buy 5! They are out in the country quite a ways. So, there is not much else to interfere. I know a combiner is probably the usual way but, I thought there might be a cheaper way since it is only for receive. They do not have a tower for the receive antenna but, they do have a multi-story building. So, feed line expense is not a concern if they use multiple antennas. Thanks Rick