Hi,

I just finished my Funtana Pro 2m plane and I have one question. Where do you guys hide your receiver antennas? After looking at the recent WC pics, I couldn't find a single plane that had an opening for the antenna. Do you just leave them inside the fuselage or do you just exit the last little bit? Thanks

Sebastian

Sebastian:

You are best not to leave the antenna inside the fuselage. In order to get the range you need, it must be fully extended and, preferably outside the fuselage. Unless you have a four foot fuselage, it won't do well inside.

What I have done is drill a small hole just aft of somewhere along the top of the fuselage behind the canope, for instance, and use about a two inch piece of very thin fuel tubing, and pass the antenna through the hole, then through the tubing, force the tubing inside the hole you drilled (the tubing acts like a conduit) then hit the tubing with a bit of CA to hold it in place. Run the antenna up to the top of the vertical stab, put a "T" pin in the vert stab, use a piece of a servo arm ( you may have had to cut one or more of the unused arms off of the servo arms. Thread the antenna wire through at least two holes in the old servo arm. Use a rubber band to attach the servo arm to the "T" pin that will act as a shock absorber for the wire. Let the remaining part of the antenna dangle behind the aircraft.

That should do it. I drew a rather poor sketch to demonstrate what I am trying to get across. Hope it helps.

DS.

Among all the pattern fliers that I know, we install the antenna inside the fuselage without any reception problems.

The way that I do it is to install a piece of clear antenna tube...from Dubro in the fuselage. Some folks glue this inside the fuse at several points. Lately, I make a block of balsa with a hole drilled at an angle so that the tube is held against the floor/top of the fuselage tail (internally). With the antenna tube installed, lubricate your antenna wire with baby powder (corn starch) and slide it into the tube. Use a piece of tape to keep it inside the tube.

That's all there is to it.

You just won't find pattern folk with an antenna on the outside of the fuselage.

Cheers,

Ken Blackwell

All outside

Very Interesting.

It must be a local thing....by country. <Grin>

Here in the USA, I've been to contests all over my region of the country and at the Nationals (NATS) and haven't seen an external antenna on a pattern airplane that I can remember in the past 5-10 years. Now most of the sport fliers do the external thing as have I on many occasions.

It's mostly an aesthetic thing, since I know of no problems with reception...at least on the frequencies on which we operate in the USA.

Cheers,

Ken B.

As you say, some do some don't. I've always had mine internally with no problems. To me, it spoils the tidy look of a well made pattern plane to have it run externally...

The Twister I have just bought from ZN comes with a tube set into the fuz for an internal aerial - saves me a job!! As long as there is no carbon in the fuz surrounding it you will have no problems with reception with an internal aerial. Most are kevlar, glass or balsa so you should be fine.

James

I personally would not put an rx aerial inside a fuz. If you have servos in the tail (as I do) it will be nearer the servo leads - a bad thing and kevlar will shield the signal slightly will it not. To my eye it doesn't detract from the appearance and if an expert who's judgement I respect tells me that it is advantageous to run the aerial outside the fuz then so be it. Best way is to run to outside and then up to the to top the fin so that at no angle does the aerial appear as a point to the tx aerial. Need to kink it.

Tons of people run them inside with no problems, but that doesn't mean it's the best way.

If you have long leads to servos in the tail, you need to separate the internal antenna and the leads. I've seen three instances (including my own where I nearly lost a plane) of interference problems when the leads and antenna were left loose. In all cases the problems were cured by putting the leads in a tube at the top or bottom of the fuse and the antenna in a tube on the opposite side.

If the leads are very long, as in a pattern plane, use heavy duty, name brand lead extensions.

I have been running antenna inside the airplane fuselage for about 10 years now, in planes ranging from 2M Pattern to 40% Scale Aerobatics stuff. Never a hint of a problem. Provided that the fuselage is not made of or covered with anything that will reflect or absorb RF energy, you should have no problems. Now think about this for a moment Suppose you do run the antenna straight outside of the airplane. For some aircraft attitudes and orientations from the transmitter, the antenna will be completely in the "shadow" of the airframe and you will have succeeded in effectively doubling the amount of airfame material in the way. So why does it work? Because RF goes through paint, monokote, balsa, ply, fiberglass, Nomex, Kevlar really well, that's why. Rumor has it that metallic colors, especially Monokote chrome can be a problem. Don't know if that is true, so duoble check if using something like that. You might have some loss of range with alot of Carbon Fiber surrounding the antenna.

Anyway, no matter what the model is made of, do a series of range checks with the antenna inside and out and see what you get. Makes sure you do this from a variety of orientations, but be 100% consistent and repeatable with the way you do the tests for each method, otherwise, your results won't mean much. Besides the neat asthetics of having the antenna inside, you also provide an extra measure of security because it can't get damaged as easily, plus you don't have to clean it. Another thing, as the antenna wire whips and vibrates outside, the wire strands will work harden, making them more brittle. Also, you aren't protecting the insulation from UV and it will harden and eventually crack. So run it inside unless the range check shows poor results!

Some of my planes have it inside the fuse and others outside. Personally I prefer it inside for esthetics. But recently I built up an MK 90 size pattern kit with the wire inside and lost control on my maiden flight(radio failure). Every single part of the plane was brand spankin new including the YS 110. I must point out that I used carbon rod for all control. Whabam!!!! The only thing that I was able use after the crash was 2 servos the rest were totalled.

In less than a weeks time I got another MK kit and again brand spankin new hardwares, YS engine, etc.... Same carbon rod set up as the previous plane. Lost it again on the maiden flight due to radio failure.

Swore to myself that would be my last pattern plane. The pattern gods were not on my side. Eventually after a month I got another 110 size pattern plane and made sure to install the wires outside. Everything went smoothly and no more radio failures for me.

Hi,

Thanks for the great info. Sorry that I didn't reply earlier but I have been very busy at work this week. The reason why I asked this question was not to ruin the nice lines on my plane. I wasn't sure where the antenna was placed in pattern flyers, but I was pretty sure that it was hidden in the fuse. Now my question is the following: I have to servos in the airfoil of the stab with extensions running through the hole rear fuselage. It was mentioned that the extensions and the antenna have to be seperated. Could someone please expand on this so that I can set up my plane correctly.

Angus: Very nice collection you've got!

Thanks

Sebastian

Hi,

How does this sounds. My turtle deck is a foam and balsa sandwich there are a couple of horizontal supports in the fuse below the turtle deck, so i can run the extensions inside the turtle deck, and the antenna in a plastic tube on the bottom of the fuse. There should be about 6 inches of seperations between the two. Would this be sufficient?

Thanks

Sebastian

Thanks, although only one is mine unfortunately. The Partner is Malcolm's and the Lazulite is David's (both younger brothers)

Angus

You will at my field.

DS

It is a good idea to separate the receiver antenna as much as possible from the servo leads. You can either use paper tubes to guide the servo extensions (a little heavy for Pattern applications) or else use a couple of those little Jtec wire guides. It's a little like building a ship in a bottle to set that up, but no harder than setting up an elevator pushrod the more traditional way. For the receiver antenna,I use a small ID plastic tube tacked to the inside of the fuselage, away from the guide system for the servo leads. The other thing to strive for is to avoid an exact parallel orientation of the antenna to the servo extensions, i.e., angle away from each other as much as you can. It gives a only slight benefit, but why not do it, it's no harder than making them exactly parallel.