I have a 4*60 with a JR receiver in it. The antenae wire runs through the fuselage and out at the bottom just in front of the rear wheel. I changed the design and added a sullivan tail wheel in order to take the weight off of the rudder. My problem is that the wire extended far enough to have the tailwheel run over the wire intermittantly. Yesterday, I noticed that the wire was worn through about 2-3 inches from the end. Can this be cut back to remove the frayed end? It would mean shortening the antenae only 3-4 inches. It would then not get tied up with the wheel any longer.

Rule #1: Never cut the antenna.
Rule #2: If you should ever need to cut the antenna, see Rule #1.

Could you run the antenna out the back of the fuse then up the trailing edge of the rudder?

When my antenna wire comes out the tail, I run it through a couple of the holes in a control horn so it stays there or tape it somewhere so it doesn't come off. Don't cut it and don't wrap it in the fuse, and if you put it in a control horn, make sure it doesn't interfere with the movement on the surface.

tape the antenae to the fuselage.

I used heat shrink tubing to repair a frayed end it worked great then tape it to the fuse.

If the antena wire looks frayed, like maybe the strands of wire inside are breaking or might break soon; then I go to the hobby shop and purchase antena wire and replace it. It should always be 39 inches long. Never cut it short. Replacing the wire requires opening the reciever case and un-soildering the old wire and soildering on the new wire. Because the reciever circuit board is very crowded with other compnents a heat sink must be used to avoid damaging any other parts. You must be fast to avoid heat from building in the board, but you want a good soilder joint at the same time. If you haven't soildered much, you may want to find someone with more experience. It takes two minutes. Most antenas will get kinked or damaged at sometime or just worn from flapping in the breeze. I consider replacing the antena regular maintenance and do so about every 6 or 7 years.

I'm going to be contrary.

Range check the radio on the ground with the engine running and stopped. If it range checks fine, it's fine. Unless you are in the habit of flying nearly OOS, it won't matter.

Antenna's aren't that finely tuned on any RXs these days. In theory you want a fraction of the wave length. But if you notice, the same RX and antenna is sold for channel 12 and for channel 60. In theory, the antenna should be differnt, but it isn't. So 2-3 inches won't matter 99% of the time.

Some RX's can have up to HALF of the antenna removed with no problems. See:

https://www.fmadirect.com/site/fma.htm?body=FAQs

and click on Receivers.

I don't know about your JR RX for sure, as I don't know how sensitive JR RX's are to the antenna. I know I've not paid that much attention to the antenna length of position on my JR's and I've never had a problem.

Montague,
Not sure where that link was supposed to lead, but....

hookedonrc,
I would NOT cut the Rx antenna. Sure it MIGHT be okay, but do you want to risk your plane on that chance?

Rx antennas are often cut down to 18" on small park flyers because they hang more than a foot out the back. BUT! their range is usually reduced to a couple hundred yards too. even a 40 size trainer will get beyond that range in a hurry.
Dennis-

Actually, I am going to seal up the frayed part which is about 3 inches in from the end. There still quite a few strands of the copper wire that are connected and the central core of strands are in place. Once sealed, I will attach it in such a way that it will not drag anywhere near the tailwheel. This way I believe I can solve my problem without cutting the wire.

I do appreciate everyone's comments and advice. Thanks to everyone.

I'm just completing my first project, a GP40 Cub. The antenna is quite long and I didn't really want it hanging out the back 12" or so. I looped it inside the fuselage. Is this a mistake or will it still work OK?

murph,
Looping it inside the fuse isn't a good idea. You want that antenna stretched out.

Usual way to handle it, is to drill a small hole in the top of the fuse behind the wing and run the wire through it to the top of the vertical stab.

Do a search on mounting antenna wires. There was a good one a few days ago with illustrations showing how to do this.
Dennis-

The link I mentioned is to FMA's website. Let's try this link:
www.fmadirect.com

From there, at the top of the page click on "FAQ's" and from that page, click on "Receivers".

Doubling over the antenna is a bad idea, it's better to let it trail behind the plane. Running it up the vertical stab as suggested is usually the best option. I usually poke a hole in the fuse near the RX and run the antenna right out and back to the top of the stab, outside of the fuse.

In theory, you want the antenna as far away from the servo leads and espeically the servos themselves as you can get it.

Also, in theory, you want the antenna perfectly straight, even a 90degree bend is "bad". But in the real world, a bend like that won't matter at all, and may actually help while in the air, when the plane is orientated in different ways. After all, in theory, you want the TX and RX antenna to be parellel but not in line with each other. On some older radios, you could cause a glitch by pointing the TX antenna straight at the airplane, for example.

But the real world is a lot messier than theory, and in the real world, we aren't relying on a "perfect" antenna length or orientation. And as a result, most of the time, if you accidentally shorten an antenna, it's not a big deal. Do a range check to be safe. But if it range checks ok, you should be good to go.

Thanks for your help guys. I appreciate it. The nearest hobby shop is about 600km or 360 miles away and sometimes its difficult to find help on this stuff. This site is great though.