Low profile Comm Antenna?

[SJ]

Well, while swapping airplanes between airports and hangars yesterday to get some work done on one of them, I took the supercub out to the little 3 walled open hangar and proceeded to roll it in. I looked up and stopped the roll just in time to see that I was going to clobber the prop if I did not move it horizontal. Feeling quite proud of myself, I then proceeded to pull the plane in and snap off the comm antenna - DUH

This is the standard fiberglass whip antenna, but with the bushwheels it makes the plane about 9 feet tall. Is there a lower profile antenna I can replace it with, or one that is more flexible? A folding one would be ideal....

Any help or sources is appreciated!

sj

[StewartB]

Here's some choices.

http://www.comant.com/prodlink01.html

Stewart

[SJ]

NICE Thanks!

sj

[SJ]

http://www.comant.com/prodpages/ci292_2.html

This is what I need. One that is PRE BENT. I just need to mount it rightside up.

sj

[mmr]

sj,
I had the same problem and put the Comant CI 122
(bent config.) antenna on. It works just fine.
Mark

[StewartB]

Steve,

I'm pretty sure the 292-2 (the last one shown) is designed to top mount. It's only 8 1/2" tall. Or you could just bottom mount it. You'd be the first Cub on the block with a curb-feeler.

Stewart

[SJ]

Steve,

I'm pretty sure the 292-2 (the last one shown) is designed to top mount. It's only 8 1/2" tall. Or you could just bottom mount it. You'd be the first Cub on the block with a curb-feeler.

Stewart

HA!

[tempdoug]

Maybe they should put little springs on them in a way that they wouldnt come loose just like a car. doug

[SJ]

I AGREE, Doug!

sj

[Longwinglover]

Can't you get one of those retractable antenna's like on a car? Power off and it retracts. I venture that any new CAR valued over about 30K has them! Super Cubs are worth way more than that.

John Scott

[12 Geezer]

Longwing, We, as in 'us people', tend to think of aircraft as technologically top-drawer. How wrong - merely ultra-conservative.

The legal stuff operates to stifle technological advances. Thank goodness for EAA and that its exemption, or all of general aviation would still be in the 30's!!!!

[T.J.]

delete

[12 Geezer]

I get 1/4 wavelength at 120 mhz = .635 m = 24.6 inches. Antenna gurus, does that sound right?

[T.J.]

delete

[12 Geezer]

234 / 120 = 1.95 ' = 23.4". Sounds mighty close to what I got and what you got, but isn't either one? - - - - Antenna wizards?

'Course, I could go measure my factory bent-wire antenna duh!!!!!!

[SJ]

Now I am thinking I should get one of those LOOOOONG antennas you trail out the back of the plane with a little reel...

TJ, I like the idea. It is also removeable which would be huge bonus in this case since I don't even have 8" clearance. It will all be moot when I put on the amphibs as it won't fit anywhere near this hangar.

sj

[Ruidoso Ron]

Steve,
I flew aircrew on a P2V Neptune all during the 60's with the Naval Reserve. We had those long trailing antennas that you reeled out and (if you remembered) in. In those days, as you flew final into either Navy Jacksonville or Navy Dallas, you could see the new roofs really stand out from the old dull ones that were on either side of final. The Navy bought lots of roofs in those days. Luck we didn't kill anybody! These antenna lengths are senthicized (sp?) now. Guess the residents have to buy their own roofs.

[Greg Smith]

I was thinking something like that. A Neptune would probably drag the weight on the end through the roof or snap the antenna. In a Cub, it would be like throwing out an anchor. SPROING! THUD!

[fobjob]

What you really need is an antenna on the bottom, so you can still communicate when you flip the cub up on it's back. ...but probably not when you rip the gear off.......the correct answer is 23.4 inches..the really correct answer is whatever works the best......if you're using a naked whip, don't forget to put the 27 pf cap between the bottom of the whip and ground to terminate the coax......(26.5 pf , actually) use a 500 volt mica. Keep the leads very short. If it has a fiberglass base, it may already have a 'shunt feed' built in....
T.J., a quarter wave whip is just half of a dipole; there is really NO SUCH THING as a quarter wave antenna, so you have to pay attention to the ground plane....

[behindpropellers]

While on the subject....

What is the best way to hide an antenna on a J-3?

[Longwinglover]

http://www.aircraftspruce.com/catalo...nnasystems.php

Supposed to work inside the "cage" of the fuselage framework. Probably wouldn't work with a covering system that uses "silver" as the buildup/UV protective layers.
We've installed one in a J3 we are nearly finished with. We mounted antenna on a piece of wood "temporarily" attached to the top stringer and a bottom crosstube in as verticle orientation as possible behind the baggage compartment. I'll let you know how it works in a month or so when we get the plane flying. This J3 covered with "AirTech".


John Scott

[fobjob]

It probably won't work very well, you have to get your antenna away from conducting elements, otherwise they become part of the antenna system....a very poorly designed part....if you want to make an invisible antenna, use a small diameter piano wire whip that will flex back by wind resistance about 45 degrees....then paint it pale blue....

[Longwinglover]

fobjob,

The antenna is glued (and ty wrapped) to a long 1X2.5 piece of wood. Antenna does not come into contact with any metal structure. The manufacturer claims it will work. We'll see.

John scott

[fobjob]

I've made antennas work(somewhat) inside metal frame buildings by orienting polarization to be as anti-parallel to the metal frame members as possible. If you had a truss member equal to half-wave, I could show you how to load it up as a radiating element, but believe me, it isn't worth the effort. Are the wings of a cub(J3) all wood with no internal metal parts?
If so, that would be the place to try an internal antenna.....

[behindpropellers]

What about in the wing? I could put an antenna in the wing on my J-5. It has wood spars.

Tim

[fobjob]

Well, it would also have to not have an aluminum coating in the dope process.....also, the thickness of the wing should be 9.6 inches, this implies that the antenna would be mostly horizontal, and the standard is vertical polarization. So, you're still looking at a compromise in performance. Still better to use T.J.'s approach with a small diameter piano wire....

[Greg Smith]

Behindpropellers had a good post on this awhile back. Something I have kept in the back of my mind to try with the VOR antenna, but the trial info from the dipole antenna installation may help you.

http://www.supercub.org/phpBB2/viewt...ghlight=dipole

[behindpropellers]

Hey Eddy-

I forgot about that! Do you have a cub on floats in toledo?

Tim

[Greg Smith]

Hey Eddy-

I forgot about that! Do you have a cub on floats in toledo?

Tim

No, I'm southwest of Dayton and am currently Cubless, sad to say. The Missus decided a house and college tuition for the boy were more important. I can't believe I married a woman with such backward priorities.

Soon... But for now I'm stuck renting when I can scrape two nickels together.

The Cub in my Avatar belongs to Cubby Stewart in Waynesville. I was getting a BFR, and that was my first time on skis. What a hoot!