Electronics > RF, Microwave, Ham Radio

Any Value in Hanging Passive Metal Bow Ties in Trees on a Hill

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jonovid:
is there any value hanging dozens of metal bow ties in trees on a hill
as passive UHF dipole antennas. one piece dipoles or strips of metal cut to size. Hz
hanging them by non conductive cord.
for radio black spots?   improved coverage over a hill.

vk3yedotcom:
Potentially.

Haven't tried it seriously but as a proof of concept got some results from this demo:

vu2nan:
Here's a similar application.

Some good commercial VHF handhelds have only one drawback - no external antenna connector.

Modification is also a problem as the rubber ducky is either integral or screwed on to a threaded stud, with no access to ground.

The result is a frustrated, repeater-bound ham. When a fellow ham in such a predicament set me pondering, realisation dawned that another rubber ducky could be used to couple the rig to an external antenna.

My own rig (which has a BNC connector!) was used to check it out. The coupling rubber ducky was mounted on the input of a homebrew SWR meter, with a dial lamp loading the output.



Rubber ducky coupling to a bulb load

The glow of the dial lamp indicated a coupling efficiency of about 20% (2.5W to 0.5W).

A 2m external antenna was then connected instead of the dial lamp.



Rubber ducky coupling to an external antenna

On-the-air tests were successful. Comfortable simplex QSOs, not possible with the rubber ducky alone, were now possible.

Nandu.

David Hess:
The bow ties could also be used as a reflector with low wind loading.

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