Parabolic Antenna Idea

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Azoic
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Location: Underwater in the Clarence River

Parabolic Antenna Idea

Post by Azoic » Wed Apr 27, 2011 12:12 am

Im working on a new design and wondered if anyone might be interested, the basic idea is a foldable parabolic, im working on a 4.5 foot golf umbrella as the support, and metal flyscreen as the receptor. I assume the feed will run up the much shortened handle, but due to feedline resistance, and tx echo, im not sure as to the suitability of that idea yet. I might end feed it via a choke, and make it receive only to test the idea. I think i should get a resonable coverage, with high directivity from anything above 200Mhz into the microwave bands, and in an antenna that can be collapsed in seconds, and tossed in the boot. Should be a good travel antenna, open to mounting via a fixed mast, or guy wires to temporary masts, or even tossed up a tree on a camping trip. What do you guys think ???

Any suggestions are welcome ( also thinking of a SOLELY indoor version, made from aluminium foil )

RADIOHEAD
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Re: Parabolic Antenna Idea

Post by RADIOHEAD » Tue Nov 08, 2011 6:28 pm

I think that you will have much more success with receive only, as getting one feed to cover the massive frequency range you are suggesting would be quite a task. Even if you could get the VSWR acceptable across that range, the illumination of your " dish " would be all over the place.

If built well, you can expect around 5db gain @ 200 MHz, adding 6db for every doubling of operating frequency.

Hope this gives you something to think about. Good Luck with it, and if you have any more questions regarding this, feel free to ask.

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Azoic
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Joined: Sat Dec 11, 2010 8:41 pm
Location: Underwater in the Clarence River

Re: Parabolic Antenna Idea

Post by Azoic » Tue Nov 22, 2011 10:10 am

It worked, but not all that well. Receives fine around 800Mhz, but no noticeable improvement below that, no noticeable Gain over a dipole between 280Mhz and 500Mhz, but it does show a Gain of around 1.1Db between 560Mhz and 700Mhz. Oh well, it was JUST and idea. Nothing ventured, nothing gained. As they say.

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