sea157

My Feedback: (30)

Will this be a good placement for the antenna on a 2.4 GHz system?
I routed them out the bottom of the plane, put them 90 degrees apart and taped them to the bottom of the plane.
Will this work all right?

pilotpete2

That's a good arrangement, but it would also work just as well inside the fuselage, since it's made of balsa.
The only time you need to get them outside of the fuselage is carbon fiber is involved.
Pete

sea157

My Feedback: (30)

One of the reasons I put them outside is because I didn't think I had enough room to put them 90 degrees apart inside.

mattnew

My Feedback: (2)

as long as its not gas/glow.... that area gets messy

electric is fine though...

sea157

My Feedback: (30)

That’s why I put the tape over the antenna so the glow fuel will not get on the antenna.

AA5BY

Actually it is not a good installation because, one antenna ought to be vertically polarized and the other horizontal. Cross polarization reduces reception strength by about one half. What your installation will do is provide superior reception some of the time and poor reception some of the time. The better installation eliminates the poor reception time by always having one antenna that is correctly polarized.

If you left one whisker sticking straight down and taped the other to the bottom of the plane... positioning would be correct. But, as others have noted, there is no need to have the antennas outside of a balsa plane. In fact, such is not helping at all. Higher frequencies like 2.4mhz are slightly attenuated by wood structures, which means that when the plane is rolling, it is exposing the antennas to no structure or double structure. The better course is to avoid weak signal issues, so exposing to one structured side of the plane all the time is better than exposing to both sides of the structure some of the time. Having said that, structure signal degradation is far less of an issue than is polarization.

sea157

My Feedback: (30)

So could someone please post some pictures of a good antenna placement on a plane?
I sure would appreciate it!

wildnloose

AA5BY (Amateur call sign??) has a good explanation.

This is what I usually tell guys at my field. I try to keep it simple.

Think of it this way, imagine the attitude your plane will fly in most of the time (flat and level). Antenna systems are vertically and/or horizontally polarized. So place 1 antenna flat to the floor of your plane (horizontal), and one antenna pointing to the sky (or ground, vertical), like an L. That way not matter what attitude your plane is in it should be no more than 45 degrees off. So you limit reception loss as best you can. Now if you want to be really anal, and have a system that support remote receivers, then place one of the remotes at a 45 degree angle. But most of the time that is not needed.

I'm glad I now have telemetry where I actually know the receive levels real-time. It really helps you optimize your antenna placement.

Larry882

Here is a picture of the antenna placement on 1 of my low wing airplanes. This is a brand new Tactic TR625 6 channel receiver with 2 flights so far. I just got the radio last Wednesday and test flew it Monday afternoon. I had multiple problems with the motor and the nosegear on the plane so I quit flying and went home. The radio installation worked perfect. I have been using this type of antenna placement for years and have yet to experience a glitch. All my other airplanes are using Airtronics 2.4 with twin antennas.
Thanks,
Larry
Larry Kopecky
Conyers, Georgia

chris923

My Feedback: (53)

[QUOTE=Larry882;11996226]Here is a picture of the antenna placement on 1 of my low wing airplanes. This is a brand new Tactic TR625 6 channel receiver with 2 flights so far. I just got the radio last Wednesday and test flew it Monday afternoon. I had multiple problems with the motor and the nosegear on the plane so I quit flying and went home. The radio installation worked perfect. I have been using this type of antenna placement for years and have yet to experience a glitch. All my other airplanes are using Airtronics 2.4 with twin antennas.
Thanks,
Larry
Larry Kopecky







Larry:

The placement is fine, but the mono-philment tips should not be covered up. Also, it is not a good Idea to wrap 2.4 receivers in foam, they are heat sensitive and can get warm. Mount them with velcro on plywood backed with foam. Mount the foam to you fuse. That is how everyone I know does it. Again just my opinion.TE]

Larry882

Ok Guys, the guy asked for a simple picture of a good installation. This works, it's pretty simple and straight forward.
Chris, where is your picture? You have got to have a digital camera.
I just charged the battery from Mondays flights. it took 326 milliamps. The battery took 326 milliamps to recharge. I flew 2 6 minute flights or 163 milliamps per flight. 163 divided by 6 is 27 milliamps per minute. Question, how hot could the receiver get drawing 27 milliamps per minute? I have been flying 2.4 for at least 8 years without a glitch and have always wrapped my receivers in foam.
Thanks,
Larry

chris923

My Feedback: (53)

Larry,

It's 10 degs here. My planes big planes are in a trailer outside. I am at work. a question was asked, if you don't like my answer, that's ok. Check out a few off the professional installs in many different threads on RCU. Learn from your mistakes, I sure have. If your install works for you great! Mine works for me, take it or leave it. Here is a picture of 4 of 12 currently flying planes. Mostly gassers, all 2.4 Futaba. I have never had a 2.4 futaba receiver fail. I was instructed by a Futaba Rep, when they first hit the market, to make sure the tip's of the antennas were always exposed and to never wrap a 2.4 futaba receiver in foam due to heat build up and possible failure. If you still fly 72mhz, ( as I still due) on combat planes. They still need to wrapped in foam ( mostly to keep from breaking the ceramic filters).

2.4 interference has more to due with environment. Our club is near a large industrial park, we have 2 huge cell tower/ micro wave repeaters near by.I take all precautions to make the best signal possible. I have seen bad installations of 2.4 equipment crash a lot of planes ( mostly spektrum, only a couple of futabas). If you live and fly out away from most interference, you can get away with less then optimal equipment and installations.

Good Luck with your flying!

sea157

My Feedback: (30)

OK if I am understand this correct you want one vertically up the inside wall and one going horizontally across the inside floor?
Would this be a better setup?
Also is it OK to use Scotch Tape to hold the antennas in position?

chris923

My Feedback: (53)

Tape is fine, just don't cover the tips.
What you have there looks fine. One in the vertical, one in the horizontal and at 90deg to each other.

All Day Dan

My Feedback: (5)

One more. Dan.

Rodney

The comment that the silver tip or bare parts of the antenna coax should not be covered is not necessarily true. The only time it would be a detriment is if the covering was of a conductive nature such as a carbon tube or metal tube. If using heat shrink, insulation tubeing, etc.; it will have no detrimental effect, in fact may help as the active portion (the bare wire) will not be deformed or bent.

philakapd

This is how I install my 2.4 antennas. I never noticed a glitch.

f16man

That looks just fine

ululi1970

I use the little hollow plastic coffee stirrers to make tubes to hold the antenna tips in place. I glue the tubes to the fuse, and use a little piece of toothpick to hold the antenna in. As remarked by other, as long as the exposed part of the antenna (i.e., the last inch or so) is not
enclosed in anything that conducts, it is fine. Therefore, plastic tubes ok, brass/aluminum/CF big NO.

pilotpete2

Excellent re-purposing of those coffee stirrers! Just make sure to rinse them out first!
I use a dab of that canopy glue RC 56 on the coax wire were it goes into the tubes I glue in the plane. This is the stuff that stays rubbery, and it peels right off the insulation without any damage if you need to pull the receiver out of the plane.........Y'know, like after a dumb thumbs maneuver
Pete

Truckracer

My Feedback: (19)

+1, no problem covering the active, small wire part of the antenna as long as you don't cover it with something conductive such as metal, carbon fiber, etc. In fact, many nitro heli flyers have discovered that if they don't use something like a tiny shrink sleeve to cover the antenna, the small wire tips will break off in time from vibration. Seen it happen several times!

AA5BY

One of the reasons against covering an antenna wire has to do with moisture on the covering. Moisture is conductive and if it gets on the antenna wire... no big deal, but when it gets on a shield covering the wire, it then takes on some of the properties of a coax shield and attenuates the signal. It should be understood that if the Whiskers were fully covered by the coax shield and not exposed to a certain electrical wave length at the end of the coax, there would be no antenna.

stegl

I prefer to mount mine one horizontally and the other verticle at 90 degrees to each other rather than both horizontally 90 degrees to each other...

Larry882

Come on Guys. We are engineering this issue to death. Sea 157 started this thread asking for advise about twin antenna wires. When he didn't get anything he understood he asked for pictures. He didn't ask about Carbon Fiber Covering, Coffee stirirs,trailers or P51 pictures. There are several pictures showing radio installations that will all work including mine.
A little bit of Knowledge can be a dangerous thing.
Thanks,
Larry

AA5BY

One of the reasons threads get over done is because of post like #9 that picture a poor installation and just because it has always worked for that poster, it should work for everybody. Other posts are then required to undo the bad information. There are four things in that picture that are contrary to the receiver installation instructions likely given by most manufacturers.

Over engineering? No.... correcting bad information... Yes.