I'm using a square loop antenna on the rooftop of approximately 15 square meter area. I use it to communicate with a group of mobile VHF radios using a station room.

Right now I'm planning to build in the same building a separate radio room that will use a different frequency, and I'm wondering, can a second station with a different frequency use the same antenna, or do I need a separate antenna for it to work?

  • 1
    $\begingroup$ Receive? Transmit? Both? Slightly different frequency or a totally different band? The answer is generally yes, multiple radios can share an antenna, but the equipment needed to do so depends greatly on the specific requirements. $\endgroup$ – Phil Frost - W8II Jan 21 '15 at 14:37

Yes, the same antenna can be used for two radios. Case in point: full duplex repeaters.

If one of the radios is a transmitter, then you must somehow direct that transmitter power into the antenna, and not into the other receivers (which would deafen them, or cook them). If all you have are receivers the problem is somewhat simplified because you need to deal with power in only one direction, the power is very low, and each receiver already has a filter.

You will probably use some combination of duplexers, diplexers, power splitters, and other gadgets to accomplish your goal. The specifics depend on the particulars of the situation, such as:

  • How far separated are the stations in frequency or time?
  • How much isolation is necessary?
  • How much loss is acceptable?
  • What's the transmit power?

you can use the same antenna.The antenna have it's frequency range. You just need change the channels of your VHF Radio's frequency to avoid conflict.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.