bill, i'm not positive but i'm 90% sure you won't be able to. i use my
own icom, the ic-706mkiig, as an example ... it has two antenna
connectors too, one for HF and one for uhf/vhf. if i don't connect an
antenna to the first i can't use HF, and if i don't connect an antenna
to the second i can't use uhf/vhf. well, i CAN .. but i won't hear
anything since i won't have an antenna lol. i'm betting it's the same
with the icom-m802 (nice radio btw), that it just won't do the function
if it doesn't have an antenna. what i'm saying is that in the 706mkiig
there is no switch to say, "hey, radio, use the other antenna instead
because that's all you've got", instead it simply goes to the antenna
that it's expecting to have for certain frequencies and if the antenna
isn't there then it just gets lousy reception and that's the end of it.