In the vid I saw, the guy had his mounted in the front pocket as well, and tested it in the back and didn't see any difference. Or at least not enough difference to really make note of, I am sure if extensive testing would be done there would be but not enough for me to worry about. Now I just need to find someone with a meter to help me tune it.
I can think of at least three possible consequences of placement:
- RF in the shack (cabin).
- Asymmetric radiation pattern (really both alt/azimuth).
- Altered antenna resonance over the band(s).
One of my favorite hack stories was from
some Yaesu FT-857 user in the UK.
He had the Yaesu ATAS-120 screwdriver antenna
on the rear of his mobile for HF.
The rig supports everything from 160m on up,
but the antenna only supports 6m-40m.
However, the guy discovered that if
he cranked the antenna to be at the end of 40m,
then watched the rig's SWR as he
slowly backed into one of the parking lot's spaces
with a lamp standard right behind it,
the antenna/lamppost system would resonate on 80m.
So he loved driving his wife downtown
for Saturday morning grocery shopping,
because then he could make contacts on 80.