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Old 11-12-2004, 04:54 AM   #1
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Default Does the length of the antenna on the car matter?

I was browsing an r/c car magazine (car action or something close to that) and they had several kits with very short antennas on the car.

Most all cars I've seen have the standard length ones, does it make a difference?
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Old 11-12-2004, 04:57 AM   #2
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the antenna lenght is set by the manufacturer of the reeciever, so dont cut it, as far as how much plastic tubing you have, it just depends on how much range you need. When I run my micro, I keep in tucked under the body and have no problems, with all my 1/10 scale cars, it is nice to have that antenna up there for reception. Play with the lenghts if you like and see how it goes.
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Old 11-12-2004, 05:01 AM   #3
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It makes a huge difference for me anyway all i did was cut about an inch off the antenna and the car went crazy after that
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Old 11-12-2004, 06:55 AM   #4
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The length of the antenna is set to a harmonic of the wavelength that you're using.

The wavelength of a 75MHz signal (which we're using) is around 13 feet - by dividing that into harmonics (1/2, 1/4, 1/8, etc.) you get an antenna that resonates to the wavelentgh. That resonation is how the antenna picks up the signal.

If you change it, even by an inch or so, it can stop the resonation and that's how you lose the signal.


DON'T CUT IT.

If you already have, ask your LHS for some antenna wire, cut a piece that is longer than the original antenna was, re-solder this new one to your receiver and then trim it so it's exactly the same length as the original again.
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Old 11-12-2004, 08:28 AM   #5
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Default I don't even have a car yet

so nothing to cut, ust curious so I don't make silly mistakes when I do get a car again
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Old 11-12-2004, 10:25 AM   #6
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size always matters
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Old 11-12-2004, 12:20 PM   #7
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Sometimes a short antenna is used for display purposes, its only so that they can get a better picture that is not the antenna tube that is actually being used when the car is driven.
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Old 11-12-2004, 12:23 PM   #8
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Default Wire & tube length

What about the length of the wire sticking out of the top of the antenna tube? i have ran them with it just at the tip of the tube, and also draped over the tube and half way down again, secured with shrink tubing, couldn't notice any difference in reception or any glitching problems, how about anyone else?
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Old 11-12-2004, 07:18 PM   #9
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if you want a car with out an antenna

demonstation on an xray
:first folt it over then rut it through the hole in the rear shock tower[in the middle]
:then cable tie it to 1 of the holes in the bulkhead
: put a condom on the end of the antenna[those little black end thingys]
:then be happy cos it wont loose signal or glitch

Last edited by pink pac man; 11-13-2004 at 03:17 AM.
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Old 11-13-2004, 10:37 AM   #10
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Do not cut or shorten the Ant wire or let it cross or touch itself.

You can run it through the tube and coil it down the outside.

Cut the tube tip (condom) and leave the tip at the top so the wire won't ever become severed. The piece left over can be used to hold the end of the wire.

Let the Antenna tube rest under the car body.

If the wire is ever damaged then you'll have to get it replaced. They are all tuned to your frequency.

In all my R/C Precision Models (girls call them toys) my antenna wires are contained in the antenna tubes or ice cube tubing and contained inside the model.

Even having the 3 foot antenna wire contained inside the hull of my One Meter Sailing yachts below the waterline still gives me a quarter mile of clear reception.
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Old 11-13-2004, 11:44 AM   #11
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Cutting my antenna ruined my car for weeks. Worse than that I couldn't figure out what was wrong.
I know it looks tacky to have an antenna sticking out of an otherwise great looking body, but it looks even tackier seeing your car slam into the boards because of a glitch.
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Old 11-13-2004, 12:15 PM   #12
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Oh, That never happened before 8-).

A glitch will occur regardless of how you position your antenna if it does occur.

I opted early on for the Futaba 3PK PCM radio. If I was going to invest in one pistol it would have to be PCM.

I have the antenna inside so it won't get damaged while sliding on the roof.

My TC4 was launched pretty high last night when a few cars decided to crash in the turn and my was following too close.

Those guys broke each others arms and I hand no damage. The antenna tube would have been ripped off during all the cartwheeled landings.
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Old 03-14-2011, 05:53 PM   #13
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Cool Under body okay?

Is it okay if I dont use the tube and just keep it neatly under the body and make sure it doesnt touch itself? I've seen it on show drift cars but dont know if it actually works
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Old 03-15-2011, 07:18 AM   #14
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Quote:
Originally Posted by TWRC View Post
Is it okay if I dont use the tube and just keep it neatly under the body and make sure it doesnt touch itself? I've seen it on show drift cars but dont know if it actually works
Yes that's okay. Many of us use a piece of lexan or something, wrap the antenna wire around it neatly, and then attach that some place.

Don't let it just flop around - that's asking for trouble.
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Old 03-15-2011, 10:52 AM   #15
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Things are a lot different (read: better) now with 2.4GHz radios. The antennas can be much shorter and easier to manage. If you notice, this thread is back from 2004 when AM/FM were still the norm.
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