Evan- done that myself, as a radioman , on more than a few occasions! they
might call it blind mound, but lots of quicksand in these modern vehicles!
Tale it you Centered on roof , drilled a hole and, there are several probs
(sepending on vehicle) to get coax down, and /or clearance for the mount.
if auto, or pickup, there is a rib that runs front to back , and (assumeing
that a headliner is installed, can be be hammered , with a screw driver to
force it lower, by 1/4/3/8 inch, so you can manouver the fitting/coax into
position. Blazers/Bronchos pose another problem, as the front seat area ,
is an opening that goes nowhere! best way I found to hide the install , is
1) there is a Second roof that must be penetrated (this kinda like a roll
bar), but, then this also doesnt go anywhere! fortunatly, there is a rubber
"coupling" to cause a seal with the fiberglass roof, and if you punch a hole
under this gasket, can feed coax to passenger compartment, and then dress,
under this rubber seal, all the way to the floor, and then to the radio,
under the door ducts!. . sadly, at one time vehicles had prepaired ways tio
get installs in, but that is NOT THE CASE TODAY! and, btw, tis violation of
law to EVEN BLOCK those GAS BAGS, and they dont even telly you WHERE THEY
HID THEM! Jim NN7K


"K9SQG" wrote in message
...
I bought an NMO style mount at Hamvention for a blind hole installation
(i.e.
no access from the back side to install it). I drilled a 3/4 inch hole
and
then discovered there isn't enough clearance to slide it in. Anybody have
any
hints or know of a brand of NMO mount that really works?

73s,

Evan