Fractal antenna orientation

Dr Who · 2011-08-31T23:43:57+00:00

A while back I had a slightly OT discussion regarding the practicalities offractal antennas for HDTV.I subsequently made an 8 element version and it works very well in areas of noline of sight/poor reception.I don't use a reflector on this and it's interesting that the antenna works wellon both the horizontal and vertical plane indoors.See below using on the horizontal. any insight into which plane is optimum for this type of design ?I was quite surprised that it works in the alignment seen in the picture.Could it be used as a beam antenna with a suitable reflector at one end ?Maybe it's just picking up a reflected/multipath signal from the metal roof ?

Aug 31, 2011 24 Replies

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Jeff Liebermann 15 years ago

Nope. Up to about 1975, it was a movable dish in the nose. Afterwards, it's mostly electrically steerable phased arrays (some of which can be tilted downward for terrain following).

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AES 15 years ago

Is the "sugar scoop antenna" considered to be a horn? -- because there certainly once were tons of those around.

A great starting point for telco history is

And then there's

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Jeff Liebermann 15 years ago

Yep. It's a horn with an added reflector at the top:

They would work from 4-12GHz (with different waveguides attached).

43dBi gain at 6GHz with about 1 degree beamwidth. Zero side lobes, which was necessary to prevent co-channel interference. I worked on a few of those in my checkered past. Aiming them was difficult. Dealing with temperature drift was tricky. Dealing with the moisture condensation problem was worse.

Many years ago, I had to deal with a 2.4GHz interference problem, which turned out to be a plastic injection molding machine pre-heater. It used a horn antenna feed by a microwave oven magnetron to evaporate out any water in the feedstock before molding. They're still around, but were moved to a different frequency a few years ago.

Also, there are moisture meters that use horns:

An angled horn is used because it covers a wide area.

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miso 15 years ago

I've seen lots of "sugar scoop" antennas in the boonies, but not powered. I've been told the liability of keeping any antenna site "legal" (as in strobe lights) far outweighs the cost of dismantlement of the antenna, but it seems these sugar scoops don't follow that rule. Now to be fair, many of these sites don't have strobes. The telcos seem to favor serviceability of their sites over say being on the highest peak. [Note how the telcos like to use microflects.] But a few I've found strobes, but otherwise in use.

Come to think of it, I recall seeing those sugar scoops on a building. Maybe in Stockton.

There is an antenna site in Hayward off of Santos Rd. that was an old fly swatter site. Roughly N 37.65950 W 121.93320 Obviously re-purposed into a comm site.

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