What do I do with the anteannae?

[Cpt Marvel]

Thats a word I have a problem with. We'll do it Southern. Antenner. What do I do with all that wire? I know I can't cross it over itself. Wrap around one skid, both skids or down the tailboom?

[1320fastback]

My heil would glitch like crazy when routed the way the manual says too. I ended up using a 1/8" wooden dowel to wrap the antenna around, not only does it now not cross itself it also counter-balances the ducted fan that I use on the tail.

[Cpt Marvel]

Interesting looking set up. Is that heat shrink tubing on there? I don't think that would work for me at this point. Something else to go crunch or snap. And make me cuss. A lot.

[Mikeyburger240]

why cant you just cut the wire where you need to?

[Cpt Marvel]

Heck, I don't know. I don't know how long it HAS to be. I know antennae have to be a certain length to receive the freqs they are designed for. I've never even hooked the battery up on a helli. I have jump started a UH1H. That suprised me. Flying in the door gunner pos with the MASTER CAUTION light flashing...pucker factor.

[Hellraser]

A arial tube - just a plastic straw mounted on the upright of a skid is the common way for FM arials - pass the arial down the center of the tube then wind it back in a spiral not letting the turns touch then tape off the end to hold it.

Regards David

[Mikeyburger240]

does the same thing apply to 2.4ghz

[Balr14]

does the same thing apply to 2.4ghz

The 2.4ghz antenna is about 2" long.

[Blade_Killer]

why cant you just cut the wire where you need to?
because it's a set length for the freq.

I wrap mine around the skid just as it comes stock, no issues at all.

[jasmine2501]

why cant you just cut the wire where you need to?
You can not cut the wire because it would reduce the range and sensitivity of the antenna. The 72MHz antenna is approximately 1 meter long - 1/4 of the wavelength of the signal. This allows the antenna to work much better than if it were some random length - incidentally, this is why lengthening your TV antenna usually doesn't actually help, and shortening it may give better reception. So... wrap the antenna around something and give the system a good range check.

For 2.4GHz systems, the "1/4" wavelength is really short, so the antennas are really short too, and mounting them is usually not a problem, although orientation can sometimes be an issue. I have had good luck mounting mine like it is in the photos - sticking out into the air and not blocked by carbon fiber.

[Mikeyburger240]

ohh, ok thanks guys

[Greybird]

You can not cut the wire because it would reduce the range and sensitivity of the antenna. The 72MHz antenna is approximately 1 meter long - 1/4 of the wavelength of the signal. This allows the antenna to work much better than if it were some random length - incidentally, this is why lengthening your TV antenna usually doesn't actually help, and shortening it may give better reception. So... wrap the antenna around something and give the system a good range check.

For 2.4GHz systems, the "1/4" wavelength is really short, so the antennas are really short too, and mounting them is usually not a problem, although orientation can sometimes be an issue. I have had good luck mounting mine like it is in the photos - sticking out into the air and not blocked by carbon fiber.
Actually, these are pictures of how not to do it. Coiling wires creates electrical interference and glitching. Even on 2.4. They should be loosely coiled farther away from the receiver and antennas, and never wrapped around frame components,especially carbon fiber. Loose wrapping also allows for some "give" in the event of a crash.

[carlosponti]

because it's a set length for the freq.

I wrap mine around the skid just as it comes stock, no issues at all.


this isn't entirely accurate. the antenna can be cut but it has to be precise. you can cut 25% off as long as its pretty accurate to 25% but you most certainly lose range. i think its quarters or thirds for how much you can cut off for 72 MHz but i cant remember but the range then falls off. also if you are not familiar with it they have antenna boosters that allow you to cut off the antenna shorter that boost range. Deans antenna is one that comes to mind. friend of mind flies a Rapter 30 with a shortened antenna and deans antenna.

http://www.wsdeans.com/products/antenna/index.html

ps this antenna for 72 only.

[Balr14]

For my larger outdoor helis, I use base loaded antennas.

[Skarn]

I use the small micro antenna like the ones at www.techmodelproducts.com

Skarn

[TMorita]

Use a micro antenna. A few are listed in the EHBG:

http://www.swashplate.co.uk/ehbg-v17/ch06.html#control-system

Toshi

[jasmine2501]

Actually, these are pictures of how not to do it. Coiling wires creates electrical interference and glitching. Even on 2.4. They should be loosely coiled farther away from the receiver and antennas, and never wrapped around frame components,especially carbon fiber. Loose wrapping also allows for some "give" in the event of a crash.

They are a little loose - and I don't plan on crashing :)

Can you give more information about this though? I see a lot of people doing it this way, and I'm really not sure what to do with miles of gyro wire other than wrap it around things... and those aren't the antenna wires. So what is the right way to do it then? Post pics.

[Balr14]

Micro antennas are base loaded antennas.

[Greybird]

One solution. And it has worked for me. The wire gets pulled out, and unplugs instead of getting ripped out by the roots. :eek: . On my cyclics(BLS451's) I have extensions that will come apart, should the front tray get removed from the rest of the heli. Hopefully, I will not test that out. :rolleyes: ESC and BEC wires also should not be coiled in with everything else. That is asking for trouble. Run those down one side and everything else on the other side. 2.4 does not eliminate interference from electrical components. I would post pics of a 450Se, but, I would have to take them. Maybe later.

[jasmine2501]

So it's coiled up next to the servo instead of close to the receiver? Otherwise I'm not sure what I'm looking at in the photo?

[Greybird]

Receivers don't like electrical interference.
Servo's could care less.

[sting35]

also counter-balances the ducted fan that I use on the tail.

Really? You are going to mention that you have a ducted fan on the tail and then post a pic that DOESN'T show the tail?

Back on topic, secure the antenna in any fashion that is reasonably neat and works. Range check carefully and adjust if necessary. Lots of good ideas offered here but don't over-think the problem. Most of the time, it's not super critical how the antenna is routed. That's especially true if you are a beginner that is not going to be flying to far away from one's self or have a smaller heli and are keeping it close in to see it better.

[sting35]

Just to clear something up too.... Yes, the length of the antenna on most of the 72Mhz receivers is approximately 1/4 of the wavelength but it's not really as critical to the successful operation of the unit as you might imagine. Wavelength matching of antennas is primarily done for the transmitter of a receiver-transmitter. This is so the transmitted power is effectively radiated OUT of the antenna. If the antenna is poorly matched (or missing altogether) the radiated energy can be reflected back into the transmitting unit and cause damage.

If you were to cut your antenna to say 36", would you have a degraded performance? Perhaps or perhaps not. But, I can guarantee you that it would be so small that you'd have to fly WAY beyond where you could still see your model to notice a difference (assuming a full range radio system, of course). You could also add a few inches to the length of the antenna and probably notice much of a difference either.

The same goes for coiling the wires. Will you get reduced range? Certainly but in most cases so small as to be insignificant. The Hitec park flyer type Rx's even came with a bobbin specifically to wind the excess antenna wire onto. Again, coiling an antenna wire (or crossing over itself) might be deleterious for a transmitting unit but will have not much effect on a receiver.

If receiver antenna design was so absolutely critical, would a coat hanger stuck into the broken rabbit ears on a TV work so well? (Yeah, I know I'm dating myself. :rolleyes: ). Or in my pick-um-up truck would I be able to hear my a.m. station better by reaching out of the window and holding the antenna? I certainly am not a 1/4 wavelength of any frequency. (Well okay, I *AM* a 1/4 wavelength of 42.20 Mhz :p ) Honestly, for our application it's just not that critical.

To summarize, do it however looks / works best for you BUT ABSOLUTELY RANGE-CHECK IT BEFORE FLYING!!!!

Sting

**** DISCLAIMER: I am NOT REPEAT NOT advocating or advising anyone to cut or lengthen their antenna. I am NOT advising or advocating anyone to use a coat hangar or any other device in place of the factory supplied antenna on their transmitter or receiver(s). If you cut, lengthen, coil, wrap, fold, spindle or mutilate your antenna(s) without range-checking it because you mis-read something I stated here... well, boo-hoo! Check it yourself before flying!

[heli_addict]

I will say that I used the micro antennas from Tech Model Products, and had very bad luck with them. I had the wire break inside the heat shrink (twice on 2 different antennas) and didn't know it until after it had caused a loss of reception and a crash. I had much better luck with a more rigid version I found elsewhere. Sorry I have no link for that.

Of course, 2.4GHz makes this a non-issue.

[1320fastback]

Really? You are going to mention that you have a ducted fan on the tail and then post a pic that DOESN'T show the tail?


Alright keep your pants on....I am waiting on a new fan as my Heli tipped over and a piece of grass (probably a rock or two also :( ) went thru the fan and broke 3 blades off. I also added SuperSkids so the balance will change and might use the antenna tube.

[1320fastback]

Alright here she is, I tried to use a cut down 3 blade fan from the GWS EDF50 as I read they are more efficient but it didn't produce the required thrust to keep the tail from TBE. I went back to the stock fan and she behaves perfectly with much authority.

The Super Skids moved much weight forward so I had to use a smaller 1/4" socket for ballance. I am still dialing in the new parts.