Tarheel Antennas Stubby 75A User manual

Tarheel Antennas, Inc.
Instruction Manual
for the
Model 75A "Stubby"
Continuous Coverage
HF Antenna
18511 CR 304
St. Joseph, MO 64505
816-671-9409 / 816-662-2416 Fax
E-mail: [e-mail]
Technical Support
919-552-8788
E-mail: tarheelanten[email protected]
www.tarheelantennas.com
UNITED STATES OF AMERICA
PROUDLY MADE IN THE

Thank you for purchasing the
Model 75A Tarheel Antenna
Packing List for Model 75A
Model 75A Antenna
6 ft. Stainless Steel Whip
Up/Down Switch
20 ft. Control Cable
Ferrite Core
Fuse Holder & Fuse
1 tube of Dielectric Compound
Manual
Packing List for Model 75A Package
All of the above -- plus the following
Small MT-1 Antenna Bracket
Quick Disconnect for the Whip
21 ft. of RG-8X Coax with connectors installed
1 pack of Coax Seal
Model 75A Antenna Specifications
Lower Mast Length -- 16"
Frequency Coverage with 6' whip -- 3.5 to 30 MHz
Power Rating -- 250 waits P.E.P.
Typical SWR -- 1.5 to 1 or less
Total Height with 6' whip at 30 MHz -- 7'6"
Total Height with 6' whip at 3.7 MHz -- 8'0"
Weight 5.5 lbs.

Thank you for purchasing the Model 75A "Stubby"
When properly installed this antenna will provide continuous coverage as follows:
3.7 MHz to 34 MHz with a 5' whip
3.5 MHz to 30 MHz with a 6' whip (supplied with the antenna)
CH-1 -- Capacitance Hat
Hat only -- 3.5 MHz to 30.0 MHz
Hat with 3 ft. whip -- 3.1 MHz to 28.0 MHz
Hat with 6 ft. whip -- 2.8 MHz to 21.0 MHz
Before proceeding with the installation, make sure you have received everything.
You should have the following:
1 - Model 75A "Stubby" Antenna
1 - 6' Whip
1 - 3/8" x 24 TPI Stud
1 - 20 ft. Control Cable
1 - Ferrite Core
1 - Manual Switch Box
1 - Fuse Holder and Fuse

Photo 1
Photo 2
Installation
Before installation of this antenna there are a
few things you might have to consider. To get
peak performance you need to mount the
antenna as high as possible on the vehicle, also
try to separate it as much as possible from other
antennas that might be on the vehicle.
We designed this antenna around using a mount
that directly mounts to ground, like a ball mount
(Photo 1). This type of mount works well.
Included with the antenna is a ferrite core that
needs to be mounted on the control wire as close
as possible to the antenna. Loop the wire
through the choke at least 3 times. This choke
(Photo 2) does two things, first it helps reduce
antenna motor noise during tuning, second it
decouples the control wire from the antenna;
without this core, the antenna will be untunable.
Next is the control box and control cable. We
preassemble everything here so you'll have a
plug and play system. If for some reason you need to cut the wires, the color
codes are as follows:
Initial Tune Up
For the initial tune up a SWR analyzer is nice to have if you have access to one. If not,
make all your adjustments with low power. Now, lower your antenna until it reaches
the end stop and go to 10 meters and check your SWR, you might have to raise
the antenna a small amount to come into 10 meters, next go to 15 meters and
check your SWR, it should be low. Next, you can go to 20 meters and raise the
antenna until you get a SWR dip there. Then 40, then so on.
Keep in mind that 10-20 meters are close together. If the SWR doesn't go below
1.5 on these bands the ground is most likely the problem, remember the ground
needs to right at the base of the antenna.
If properly installed this antenna will have a standing wave below 1.5 from 3.5 to 30
MHz. We know that every antenna installation is unique and it is impossible to
describe all the scenarios in this manual. However, if you are having problems with

this initial tuning please call.
Operation
Remember that when the coil is all the way in it's resonant on the high bands and all the
way out on the low bands. It will take a little time to get use to this style of antenna, some
mark the antenna with tape to mark the approximate location of the bands, some just
listen to the noise level increase on the radio's receive when its close to resonant. When
you fine tune you need to transmit a low carrier (AM, FM, CW) at 5 to 10 watts and watch
the SWR meter till the dip.
Running an Amplifier
This antenna is designed to handle up to 250 watts P.E.P. Do not exceed these ratings.
Always do the initial tuning with low power then apply more power if needed.
Maintenance
Very little maintenance is required for your Tarheel Antenna. You should have years of
trouble free service from this antenna. You've made a large investment for a mobile
antenna. Here is a tip to help take care of your investment.
We use an automotive finish on this antenna so whenever you wash and wax your
vehicle raise your antenna and wash and wax the shaft and the bug shield (Lexan tube),
with wax on your antenna the bugs will have a harder time sticking to it.
About once per year or so, depending on how much driving you do and where the antenna is
mounted you will need to wash the coil to remove any road grime, no parts to replace. Also a
dirty coil will show vertical black streaks.
Here's how to clean the coil:
1. Run the antenna up till all the coil is exposed.
2. Remove the are 3 screws in the top Delrin Cap.
3. Then slide the Lexan bug shield down to expose the coil, next feel the coil, is it sticky?
4. If so it's dirty, now wipe the coil with alcohol.
5. Then lightly scrub the coil with a Scotch-Brite pad (available at any hardware store).
6. Then one more wipe with alcohol and that's it.
7. Reassemble the Antenna.
After you have the antenna reassembled, now is the time for a good cleaning on the outside.
Use the alcohol to remove the grime off the tube and Lexan, next get a good coat or two of
wax on it.

Relative Tuning Positions
The following photos will show you relative tuning positions of the Model 75A "Stubby"
Antenna. LEXAN COVER REMOVED FOR CLARITY
Model 75A "Stubby" -- full down position with 5 ft. whip -- 34.0 MHz
Model 75A "Stubby" -- 21.2 MHz
with 5 ft. whip
Model 75A "Stubby" -- 14.2 MHz
with 5 ft. whip @ 1/2" of coil showing

Model 75A "Stubby" -- 7.1 MHz
with 5 ft. whip @ 1 1/2" of coil showing
Model 75A "Stubby" -- 3.9 MHz
with 5 ft. whip @ 4" of coil showing
Warranty & Guarantee
IF for the 1st 30 days if for any reason you are not completely satisfied, return the
antenna undamaged for a full refund less the shipping charges. The antenna has a
ONE YEAR NO MATTER WHAT WARRANTY to the original owner. If for any reason
(other than damage due to unauthorized disassembly, negligence, improper
use, or use of Non-recommended Controllers) your Tarheel Antenna fails to
perform due to quality or workmanship Tarheel Antennas, Inc. will at our discretion
either repair or replace at no charge for parts or labor. Shipping charges are your
(the customer's) responsibility to and from Tarheel Antennas' repair shop.
We here at Tarheel Antennas hope you enjoy one of the best performing, best built, best
looking motorized antennas available.
We here at Tarheel Antennas hope you enjoy one of the best performing, best
built, best looking motorized antennas available. Please pass along any
suggestions you may have to make our antenna better. All suggestions are
appreciated. Also when you have your antenna installed please send us
pictures.
Thanks,
Tarheel Antennas