Antenna system for todays FM technology

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Jeff
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Antenna system for todays FM technology

Post by Jeff »

Hi
We broadcast on the 88.0 frequency at 10 watts and looking at changing our current omni diapole.
Our tower is 35 ft / 11 metres off the ground, we use 60ft / 36 metres solid core copper cable with shielding with N plugs at both ends
Tower is on a plateau:
To the east the land is flat and is classified as national park and goes for 7 miles /11 km before it drops significantly to sea level, audience in this direction makes up 5 %
To the north the land is a gradually slope, audience in this direction makes up 30 %
To the west the land goes for less than 1/2 mile / 800 metres and drops sheer cliff face, audience in this direction makes up 35 %
To the south the land goes for less than 3/4 mile /1100 metres and drops sheer cliff face, audience in this direction makes up 30 %

I would like an antenna that can get the signal to the potential audience that lays under the cliff face to the west and south (demographics put it at 27,000 folk plus highway audience of 130,000 per day (one way) who sit in their cars at peak time)
I see your exterminator has to be placed 70ft above the ground to get better ground hugging penetration however our tower is half that height so I'm thinking that perhaps the circular dipole antenna or PCS-0210 single circular dipole configurations may be suitable. My reasoning is based purely on the variety of modern car aerials that are shaped to the curviture of the car and smart phones that are tucked away in a variety of postions ie.. ones shirt or pants pocket or hand bag plus the traditional home stereo units owner continues to lets the FM aerial wires hang down or stick to the wall with drawing pins. The consequence I feel is I/we require an antenna that can put out a simultaneous vertical and horizontal signal to cater for todays technology. As always welcome your thoughts and suggestions.
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pcs
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Post by pcs »

PCS-0210 works, but is dirt-cheap low cost antenna, the problem when placing it on a tower on a hill like that is that wind will break it pretty soon.

You will have to use something like this:
http://www.pcs-electronics.com/500w-nar ... -1929.html

This one has the added bonus of being wideband so you don't have to tune it:
http://www.pcs-electronics.com/wide-ban ... -1909.html

What people use nowadays mostly are 4-8 bays of circular dipoles, some of these are listed here:
http://www.pcs-electronics.com/multibay ... -1931.html

If you can afford stainless steel wideband circular dipoles, go for those. If your budget
is tight you have to compromise so tunable narrowband dipoles come into play.

Very salty environment, close to seaside, can eat aluminum antennas eventually. Steel
is more durable.

At least 4 bays would be great.

You can also give Exterminator a try of course. It will give more range per $ invested,
but circular polarization, as you correctly noted, has its advantages.
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
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