That is what DUPLEXERS are for! Tho, not to radios, on the same band.
they will allow one antenna (multiband) to be used by 2 , or 3 separate
radios at the same time! Comet, and couple other outfits make them.
(for vhf /uhf radios, some with an AM radio port for car radio).



Chuck W. wrote:
I'm wondering what is the best practice for connecting two transceivers
to a single transmission line/antenna, or even if it is advisable to
do?

What would be great is if there was a switch that would share the line
between the 2 transceivers when no outgoing RF is present, and switch
everything to one rig when RF is sensed. However, I haven't seen a
product that does this!

thanks for any thoughts,

73,

Chuck
KB5GC