Hi Guys,

Ok im not exactly a beginner but i know alot of good experience ppl use this forum soo here goes the question............

I kinda had a tree jump out on me and grab my 3D plane, its all ready after a few repairs to go but i done a range test and was about 50-60ft with the ariel on the tx down until i had problems. I then tested another one of my planes and again was the same distance...... i then check the Futaba website and its stated the antenna for the rx should be located at the top of the fuse ?????? and should be 100ft range with ariel down, but most of my planes including these 2 exit from the bottom, very close to the ground........ althou ive never never had any problems in flight with this setup but after reading that its kinda got me thinking so is this just a ground test problem as like i said in flight thier fine ?

Or should i redo them all and exit from the top ???????

Thx in advance for any help........

I prefer to run my antennas on top of the fuse, to the top of the vertical stab, but I'm guessing that your "short" range test is merely a result of the bottom location. With the antenna on top it's further away from pushrods and other potential RF generating internal components. My Futabas generally test to about 100 feet.

I know any number of people who run there's on the bottom and don't have problems with it. I do think it's more likely to get hung up and ripped out though, especially flying off a grass strip with high bushes at each end.
Dennis-

I put my antennas internal. They are not always straight (in fact I don't think I've ever seen one straight), and sometimes they do 90 degree bends and even 180 degree bends. Sometimes they will do a complete 360. But MOST of the antenna is (Relatively) straight.

I have never had any kind of problem resulting from a bad antenna placement, BUT, I should also stress that I am not one of those fliers who likes to see how high he can go, or how far away his plane can fly. Personally, I just think that's bad form.

I like to keep the plane where I can see it.

PS and BTW, I DO occasionally get VERY high when practicing spins, so I do have good range.

Thx guys after reading the first post i changed one of the two planes in question........... and mounted it on top into the vertical stab and it made a BIG difference in range, much much further...... so i think on the safe side im going to change all the others i have..

Thx guys for your imput

I always thought it was better on top:-) But my last two planes are
internal and they are stright(little guide tube that's a pain to get wire
through with stops on both ends) and as far away from rods as possible
(even tho there C.F. rods) With both I get over 100ft. on my range
check with plane sitting on table. While flying I stay within 25-200yds.
But at times I do fly high.. The way I figure, It should get the best
reception since its an unblocked path..

Dragon heart, to be a valid test, you need to have the airplane well above the ground for the test. I'd almost guarantee, that if you set the plane at least 6 foot off the ground on a non conductive surface, you will not be able to detect any difference in range as long as all other elements remain the same.

I agree totally with Rodney. I believe in the air it really doesn't matter all that much. However I do tend to go internal or out the top. Just for the sake of keeping the antennae away from the grass.

Mark Shuman

I usually run my antena down the outside of the fuselage, secured inplace by a bit of clear tape, or coloured electr. tape -- easy to install & remove, plus absolutely no reception problems.

If the antenae is on the bottom, just fly inverted..... Actually, I have run them internally, on top, on the bottom, and have found no differences that were detectable. I do fly JR, but I wouldn't think that brand would have any different affect.

Rodney is right by my experience, if the plane is on the ground and the antenna is out the bottom the range check will be reduced compared to the antenna running out the top of the fuse and back to the tail. Set the plane up on a table or a stand and check it again, you may be suprised. Something else to consider. If you have 10 inches of "extra" antenna hanging off the end of the plane and that "extra" length is enough to touch the grounbd when the plane is at rest, just for fun do a range check with the antenna touching the ground on a wet day. I tried that once and got less then 20 feet before I began to see a loss of signal.

I am with Minn here. I almost always put my antenna inside the plane. I have never had a range problem with the basic installation. I do try to keep the antenna as straight as possible, and to keep it at least an inch or two away from servo's and other wiring. Also, when I change direction, I try to keep it at least an inch away from itself as well, such as running down one side of the fuse, then when the tail section gets narrow, run straight accross and up the other side of the fuse.

Also, I always do my range checks on the ground and expect at least 100 feet distance without trouble.

If you go out to a proper antenna test range you will see the antenna under test up off the ground at least 1/4 wavelenght to reduce ground distortions to the pattern. We are interested in airborne range, so unless you plan to fly at 100 meters distance at less than 6 feet up I don't see the placement on top or bottom as a problem. Yes, the ground range check will be affected, but the flying range will be more dependent on metallic and active elements within the plane such as wires and pushrods in proximity to the antenna. For the record, I fly scale and install the antennas internally. (Most full size aircraft have the antenna elements inside a housing too)

Be more concerned of the metal and active wires in proximity to the antenna than if the antenna is out the top or bottom in flight.

quint

Doesn't matter top or bottom. Just don't fold the antenna back into itself, or route it near any servo, extension wires or metal pushrods.