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Topic: Bare aluminum wire

Phil Hill
I love my cootie bug

Posts: 7595
From: Hollywood, CA USA
Registered: Mar 2000

posted 08-08-2002 04:48 PM

It's good to finally see what we were all talking about...

Hey Paul, it sorta reminds me of the old ham radio "halo" type antenna series like the "Saturn 6". Ummmmm, but that was made of alumium tubing and tuned with big ol' capacitor plates in the "ring". Had a killer gain and pattern...even more when stacked as an array.

Also, while it is very important to make sure all high-power connections are tight, I would be *extremely* careful about tightening the service feed to any main panel, sub-panel, or meter panel. It's wise to call an electrician if not familiar with these deadly live circuits that in many cases must be serviced while engergized.

There are anti-corrosive pastes made specifically for antenna use that can be found at ham radio suppy stores.

I still would be concerned about the wood. It would suck-up the RF radiated power by absorbtion depending on length and especially when wet....even if coated.

>>> Phil

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John Anastasio
Master Film Handler

Posts: 325
From: Trenton, NJ, USA
Registered: Sep 2000

posted 08-08-2002 09:44 PM

These antennae are popular with the FM "Pirate Radio" folks because they demonstrate a high gain in the lateral direction and almost no sky wave. They're also easy to stick up and pull down real fast to avoid the authorities. The design is not unlike commercial transmitting antennas used by FM stations. I have a two-bay circular dipole that looks a lot like this one at the transmitter site I manage, only it's 450 feet in the air and made out of stainless steel pipe. If you're planning to do a little guerilla broadcasting, be warned; it's easy to exceed the legal limits with this antenna, even if you're using a transmitter operating with a legal output power.

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Paul G. Thompson
The Weenie Man

Posts: 4718
From: Mount Vernon WA USA
Registered: Nov 2000

posted 08-09-2002 04:33 AM

Phil said:

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Also, while it is very important to make sure all high-power connections are tight, I would be *extremely* careful about tightening the service feed to any main panel, sub-panel, or meter panel. It's wise to call an electrician if not familiar with these deadly live circuits that in many cases must be serviced while engergized.
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Phil, Absolutely! That's why I mentioned something about "Or at least have them checked by your electrician..."

Thanks for bringing that up again. I didn't put enough emphasis on that statement.

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John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000

posted 08-09-2002 07:51 AM

How effective would this antenna design be for use with a RECEIVER? Specifically, for use with a scanner in the aircraft band (118 to 136 MHz)? Would vertical/horizontal polarization of the signal be an issue? I live about 10 miles from the Rochester airport, and would like to use a gain antenna to get clearer reception of the tower and aircraft on the ground, while having an omnidirectional pattern for airborne planes.

Would this be a good design to use as an omnidirectional antenna with an FM stereo receiver?

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

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John Anastasio
Master Film Handler

Posts: 325
From: Trenton, NJ, USA
Registered: Sep 2000

posted 08-09-2002 08:36 AM

It would only be an excellent antenna for the one frequency for which it is tuned. It would indeed be an omnidirectional antenna. Your best bet for an antenna that you want to pick up a specific source with like the local airport tower would be directional one that exhibits high gain in one direction only, like a Yagi, parabolic or corner reflector that you could point right at the airport's antenna system. If you want to pick up the aircraft in the sky as well, they're coming from a higher reception angle. I'd say that your best bet would be a vertical antenna with a good ground plane tuned to the tower frequency....then you'll get everything. The best way to get airports is to get your antenna well-tuned and up as high as you can.

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John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000

posted 08-09-2002 09:00 AM

John:

Thanks. I've already got a vertical antenna with ground plane, but I probably should remount it higher than the 20 feet it is now at, especially since there is a hill that obstructs "line of sight" between my house and the airport. Shouldn't I tune it for the middle of the band (127 MHz.), rather than the ROC tower frequency (118.3 MHz)?

Any hints on getting the ground side of the conversations for the regional (CLEVELAND, TORONTO) Air Traffic Control (other than going up in an airplane or building a mile-high antenna tower)? Is there a listing of where the regional ATC transmitters are located, so I could aim a high gain directional antenna at them?

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John Anastasio
Master Film Handler

Posts: 325
From: Trenton, NJ, USA
Registered: Sep 2000

posted 08-09-2002 09:24 AM

Absolutely right. If you want to get all the ATC frequencies, it should be tuned to the center of the range. The information about the antenna sites is available from the FAA, but they may be a bit wary these days. You can glean tons of info for about six bucks by going to your local flight school and buying the "sectional" chart that pilots use for navigation. I think that Toronto shows up on the Lake Huron sectional chart. These charts show not only the airports, but all the frequencies for ground control, ATC, VOR, ATIS, field elevation,locations, etc. The problem with these is that they're aimed at (you guessed it) AIRPLANES, up in the sky, not antennas down on the ground. Some large airports now have their towers available for listening via RealAudio. The holding pattern for Newark International is right over Yardley, PA so there's always something to hear at my house in Trenton ( you can actually watch them circle) , but I can't get the tower from here.

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