Thoughts on hidden, bumper mounted, wire dipole?

[jparks29]

Looking at going low profile, only way I can think of doing that is with a wire dipole mounted behind the bumper...

Two problems I'm thinking of...

Vertical Vs. Horizontal polarization, easy 3-6db loss.... Reflection from metal bumper, which would be within about 2 inches from the antenna itself....

Looking @ vhf/uhf @ 110 watts...

Suggestions?

[jim202]

I guess the big question is just why would you want to do this? There has been a requirement
over the years to come up with some sort of covert or unseen antennas. These generally do
not perform very well and have poor range.

If your looking to just do this for no real reason, then have at it. If your looking to maintain
good communications and just don't like antennas sprouting from the roof of the vehicle,
that is a whole different prospective.

You will probably do better in obtaining suggestions, if you provided just a little more of a
hint on how you intend to use the antenna and what kind or range your expecting to obtain.

Jim

Originally Posted by jparks29

Looking at going low profile, only way I can think of doing that is with a wire dipole mounted behind the bumper...

Two problems I'm thinking of...

Vertical Vs. Horizontal polarization, easy 3-6db loss.... Reflection from metal bumper, which would be within about 2 inches from the antenna itself....

Looking @ vhf/uhf @ 110 watts...

Suggestions?

[jhooten]

Sti-Co: Custom Antenna Supplier and Manufacturer: Covert Antennas

[Fast1eddie]

Can you mount a unity gain antenna inside on the rear deck??? I am going to put one in my '07 Milan and have seen them in police cars. They work well, but can have directional and blocking tenencies due to shielding.

[zz0468]

Originally Posted by jparks29

Vertical Vs. Horizontal polarization, easy 3-6db loss....

Cross polarization losses are typically around 20 db.

Originally Posted by jparks29

Reflection from metal bumper, which would be within about 2 inches from the antenna itself....

Between cross polarization losses, and the effects of proximity to the bumper, it's a fair bet taht it won't work well, and probably lots of directions where it won't radiate at all.

Originally Posted by jparks29

Looking @ vhf/uhf @ 110 watts...

Suggestions?

That's a lot of power to waste...

Why don't you tell us what kind of car it is, so people can suggest better locations.

[fineshot1]

Originally Posted by jparks29

Looking at going low profile, only way I can think of doing that is with a wire dipole mounted behind the bumper...

Two problems I'm thinking of...

Vertical Vs. Horizontal polarization, easy 3-6db loss.... Reflection from metal bumper, which would be within about 2 inches from the antenna itself....

Looking @ vhf/uhf @ 110 watts...

Suggestions?

I installed one of these antennas once with very disapointing results for the owner
and he did not have a 110W radio. I think they are a gimmick/garbage and would not
recomend it especially with a 110W radio. Most stealth antennas are not rated for
110W and also for the reasons you stated above I would steer clear of them.

[prcguy]

Check this site out that's a friend of mine:
Disguised undercover covert license plate antenna,fender,cowel,bumper antennas
The license plate antenna is a real compromise but if its for undercover work in a large public radio system that is designed to work well with hand helds, (voter receivers, etc) it should work ok. A friend installed one for general purpose amateur/GMRS use and it was very disappointing.

I've made and used simple 1/4 wave verticals from thin wire taped to a window with two ground radials along the lower window and it works surprisingly well but 110 watts inside a vehicle would be a health hazard.
prcguy


prcguy

[radioman2001]

I second the motion for the rear deck, I installed many an antenna on the rear shelf for the DEA in the 70's and 80's. To hide them a little better we would take a Kleenex box and put it over the antenna. Problems foreseen today are rear window defoggers, creates an electric field as if it were sheet metal. You could also install the whip by the A pillars in the front of the car, I also had installed what would be described as a curb feeler antenna. Worked sufficently for the Chief of the department who didn't want an antenna seen on his car. Stay away from cross polarization, keep the antenna verticle at the very least, where ever you mount it.

[gewecke]

Years ago I installed a quarter wave nmo on the rear package shelf of my 88 dodge diplomat. Uhf was 4" from left pillar nad vhf was 4" from the right. These worked quite well as this car did not have the rear defogger! The FBI favored this idea back then on many of their covert vehicles.
N9ZAS.

[jparks29]

whip on rear deck is not good. the car creates a farraday cage, and pumps 110W into the back of my skull and goes through the defroster grid... BAD idea.

It'll be in a crown vic, stealth is a must. Can NOT use disguise fender mount antennas since they don't have any (except oddball '05 MY).

[jhooten]

In glass antenna?

Sti-Co: Custom Antenna Supplier and Manufacturer: Embedded Antenna System

[jparks29]

Originally Posted by jhooten

In glass antenna?

Sti-Co: Custom Antenna Supplier and Manufacturer: Embedded Antenna System

They've been known to crack rear glass...