We Recommend
using nothing smaller than 2" by 2" by 3/16" wall thickness....square tube for all
right angle mounts that are attached to the frame of the vehicle and extend out to the side of the
vehicle.
Please
Do Not take a chance with a lighter or smaller mounting material for your mount....it could
break off and go through someone's windshield !
"S
ee our mobile photo gallery
" and "
Antenna Mounting
" for more ideas.
In our accessories page we have a 1"
national pipe thread
stainless Pipe Adaptor with a 1" pipe
thread on one end and 3/4" standard bolt thread on the other used for antenna mounting.
Heavy wall threaded pipe "
Electrical or Plumbing type
" of your choice can be screwed into our
stainless pipe adaptor. The antenna threaded rod along with the 3/4" by 10 TPI stainless threaded
rod is screwed on to the other end of the stainless Pipe Adaptor.
We have customers that use two of the stainless Pipe Adaptors for mounting the antenna.....one
adaptor is used at the bottom of the antenna and the other is mounted or welded to a plate that is
bolted to the vehicle. This allows you to use different length pre-cut and pre-threaded pipe nipple
for your install from Home Depot.
If the threaded pipe nipple is longer than 6 inches you will need to support the pipe nipple! "See
our mobile install photo gallery for these type mounts."
The RF Choke
The motor control leads on our HF mobile antennas are in close proximity to the RF current traveling on the
stainless tube. These leads must have the RF or common mode removed to stop the travel of RF on these
control leads. We decouple them with clamp on 31 type material beads so the antenna does not see them as an
active radiating part of the antenna. By doing so we also help to stop common mode from migrating into the cab
of the vehicle. This is accomplished by installing the two supplied 31 type clamp on chokes. These chokes are
ample for 100 watts of power. Additional chokes will be needed if higher RF power is used.
Install one of the two supplied 3/4 inch ID 31 type material clamp type chokes on the coax and one on the
antenna control cable.
5 to 6 turns of RG-8X providing 4 inch loops through the choke is needed to decouple the coax from the
antenna.
If higher power is used, install two 3/4 inch ID 31 material clamp type chokes one on the coax and one on the
control cable inside the vehicle where the coax and antenna control wire just enter the vehicle. This will help
stop Common Mode from entering the vehicle. With 500 watts of power you may need to install additional
chokes. If you have any other antenna installed on the vehicle with coax entering the vehicle it will need to be
choked also, to stop any common mode that occurs in the near field that will migrate onto the outside shield of
of any coax used!
If you have an 18 gage two conductor wire at hand and wind at least ten turns through a 31 material 3/4 inch ID
clamp style choke, it will increase the impedance of the choke many times over. For every loop through the
choke the impendence will square. This will help if you are experiencing common mode current or high SWR.
Use the #18 gage 2 conductor wire instead of the 2 conductor cable that is supplied with the antenna.
In cases when high power is used, it become necessary to decouple the coax and the control cables just as they
enter the inside of the vehicle.
Remember: the coax and control cable are in the near field!
The #31 material
clamp type choke will work well for this issue. Make sure both coax and control cable have the chokes installed