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Question about RV wingtip antennae

VHS

Well Known Member
Can anyone tell me how much room you have fore-to-aft in your wing tip? Is there room for an antenna 36 inches long ( its okay if the ends have to roll a bit)

Thanks,

Allen
VHS
 
Can anyone tell me how much room you have fore-to-aft in your wing tip? Is there room for an antenna 36 inches long ( its okay if the ends have to roll a bit)

Thanks,

Allen
VHS

Allen,

There is nearly 60" in the wingtip depending on lighting that is installed and the particular style of tip. A 36" antenna should be doable.
 
Sam,

Thanks, I was wondering about running 1/2 Wave dipoles horizontally. If anyone has the need, you are welcome to my prototype...its not pretty, but it seems effective.

Allen
VHS
 
Allen, can you post a diagram? I'll be installing an MT-RTG in a Glastar wingtip within the next couple of weeks, and am looking for some sort of antenna that I can use.

Thanks,

-Dj
 
I have not the slightest clue as to how a post an image here....a very simple dipole is two 1/4 wave elements ( Nominally, 18 inches each) connected to the end of your coax; one side to the center conductor, and one side to the ground shield. Sort of in the shape of a "T". I started experimenting with these as an alternative to the rubber duck antennas people have been using in Gliders. Rubber duck whips don't load up very well, and this makes some transmitters ( like my MT-RTG) become "swamped" with power due to high SWR. Even a really awful 1/2 Dipole seems to load up enough to run my transmitters at full power, and there is a massive increase in effective radiated power. It may well be that Pete's J-pole antenna is superior, so I am hoping for some anecdotal evidence.

Allen
VHS
 
If memory serves, a 1/2 wave dipole has minimum gain along the axis of the antenna. Also, the metal structure tends to shield any antenna. So if you mount a 1/2 wave on the wingtip, you'd only be able to recieve from stations off your wingtip.

That's why composite airplanes (made of fiberglass) have their dipoles mounted in the vertical tail, and why metal airplanes have their antennas mounted on the underside (except GPS, which is on top)

In short, that might not be the best place for an antenna.
 
I almost completely agree....except the RV has a fiberglass wingtip, and most owners are reluctant to drill another hole in their belly. At altitude, horizontally polarized antennae that have a theoretical net power loss seem to work remarkably well! Since the receivers (digipeaters and I-Gates) often surround the ship in every direction, the null from metal shielding does not seem to be all that limiting a factor, working reasonably well even with out tiny 300 Milliwatt transmitter ( soon to be discontinued again, by the way)

Allen
VHS
 
Bazooka!

Here are plans for a simple coax-based antenna. I have built a few and they are not quite as good as the j-poles, but easier to build.

Might be worth a try. The screengrab is from the site above and is not my own.

2%20Meter%20Vertical%20Bazooka%20-%20Build%20A%20Vertical%20Bazooka%20from%20Coaxial%20Cable%20by%20VE3VDC%20-%20Google%20Chrome%203202011%20112249%20PM.jpg
 
Pete,

What I am talking about is a center fed 1/2 wave dipole, but the principal should be much the same.

Allen
VHS
 
Sam, thanks for posting that picture! I used to build those often when using a 2m handheld in my office, just taped to the window. I didn't recognize it by name, but I should have. At one point in time (more than a decade ago), I used to be able to make one of these in about 10 mins. Guess I'll see if I "still have it"... :)

-Dj
 
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