I have a GMRS radio and VHF/UHF radio in car. I have an antenna mount and cable installed. I install appropriate antenna for the radio in use and manually remove and attach cable to matching radio. It’s a PITA. Is there a way to split the cable to go to both radios? So I don’t have to remove connections. I saw an A/B switch. But was hoping I could use a T connector or something. See illustration.

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1 Answer 1


You need a switch. Connecting two transceivers directly to one antenna is a great way to destroy one of them — as soon as you transmit with one, the receive circuit of the other one will see several million times more power than it's designed to handle.

If you only wanted to use 2m on the ham rig then you could probably use a diplexer to send the 2m frequencies to the ham rig and the GMRS frequencies to the GMRS rig, and get enough isolation between them to avoid trouble. But the 70cm ham band and the GMRS band are too close together to make that idea practical.

  • $\begingroup$ Thank you so much. I didn’t think it would be a good idea. I will set up a A/B switch. $\endgroup$
    – Merlynda
    Jun 26, 2021 at 3:13
  • $\begingroup$ You can also get a T/R switch for each radio that would cut out one radio when the other is transmitting. Of course, some care has to be taken to make sure this is wired correctly. T/R switches are commonly used when you have a separate transmitter and receiver in a radio, or when you have a preamplifier for receive that must not be in the transmit path. $\endgroup$
    – user10489
    Jun 26, 2021 at 4:35
  • $\begingroup$ @user10489 yup. Thought about mentioning that, but a lot of mobile radios don't have keying lines :) $\endgroup$ Jun 26, 2021 at 17:08
  • $\begingroup$ T/R switches work better with keying lines, but some just key off the transmit power itself. $\endgroup$
    – user10489
    Jun 28, 2021 at 0:36

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