two uhf's on one antenna

Low loss coaxial switches are available, just make sure it's suitable for the frequency. If you have easy access to the back of both radios it would be cheaper to just unscrew the coax from one radio and connect to the other.

Probably a converted commercial or Ham rig. I've got one here that would do 45 if modified.

Hi Gra

Can't do it with a splitter , because as you suggest power from one will damage the other.

It can be done automacitally using devices known as directional couplers which couple energy in the forward direction and cancel it out on a their 3rd port.

While there are low cost and broadband TV types devices available they are really meant for receiving , and would be marginal on 5watt and would be over powered by 35watt.

Robin Miller

P.S.
5 watts is legal max on UHF but there are many modified units around and commercial units that run a lot more power. While a few more watts
can be handy is basically not worth running a lot more power than the person
you are talking to because as long as both units are up to scratch you might send out a strong signal but can't here there weak reply signal.

I would go so far as to say that often in practise your range can be effectivily
reduced by using a high powered rig unless you are talking to a mate also with a high powered rig.

The reason for this is a little strange but its because primarily high powered units
are generally moded commercial units. Contary to what some believe commericial units as a class do not have more sensititive receiving sections to match the higher powered transmitter side.

Generally they are more concerned with reduction of interference effects with cute names like intermodulation etc. So actual receiver sensitivity is often less.

You could connect your "spare" transceiver to a low-gain antenna inside the car - get a CB Handheld antenna with a BNC plug and plug it into a coax cable with BNC-UHF adapter.

This way you can use the 2nd CB to monitor a second channel reliably (scanning means you may miss a signal)

e.g. one on Ch11 and one Ch 40

Mike