Antenna placement or lack of

[Jeff@TireBalls]

I've been out of the RC scene for about 15 years but just got back into it with an Axial Wraith. I've noticed in most pics of crawlers that they aren't running antenna's. Where is everyone running their antenna wires if they aren't running it straight out the top?

[jason]

The newer 2.4ghz systems don't require the long antennas like the am radios back in the day. Most new receivers only have short 3-4" antennas coming out of them, and most guys just tuck them away under the body.

[Jeff@TireBalls]

Mine is a JR XR3 FM, not sure what ghz it is.

[1r3land]

Originally Posted by Jeff@TireBalls

Mine is a JR XR3 FM, not sure what ghz it is.

That's a 27mhz fm radio, so your receiver will have a longer antenna, as stated above most people run 2.4 ghz now ( no need for long antenna on receiver or transmitter) 2.4 is newer technology

If you plan to use that radio you have you will have to run antenna out the top for best signal, or upgrade to a 2.4ghz ( recommended )

I prefer 2.4 all day long myself

[Jeff@TireBalls]

Great, thanks for the info guys!

[Charlie-III]

Originally Posted by jason

The newer 2.4ghz systems don't require the long antennas like the am radios back in the day. Most new receivers only have short 3-4" antennas coming out of them, and most guys just tuck them away under the body.

Originally Posted by 1r3land

That's a 27mhz FM radio, so your receiver will have a longer antenna, as stated above most people run 2.4ghz now ( no need for long antenna on receiver or transmitter) 2.4 is newer technology

If you plan to use that radio you have you will have to run antenna out the top for best signal, or upgrade to a 2.4ghz ( recommended )

I prefer 2.4 all day long myself

Yes, as mentioned, the older AM & FM radios (they also had replaceable crystals for each frequency) had long antennas for both the TX & RX.
The newer 2.4ghz radios have short antennas. They are also a bit more immune to "noise" from the outside, things like the brushes on the motors. That is why you HAD to run caps on the brush hoods to kill most of that noise.

One good thing about AM & FM though, the signal travels through water BETTER than 2.4ghz. So if you run a rig that will spend time in deeper water, you "may" want to keep that radio. It appears that 2.4ghz signals die off if the antenna is more than 1-2" deep in water.

[@ 1r3land..... isn't 27mhz AM & 72mhz FM?]

[@ Jeff@TireBalls, your radio is either ~0.27gz or 0.72ghz if I did it correctly.. Also a lot of the newer radios have the ability to save settings for more than 1 rig, thus easier to swap between rigs without twiddling dials to get things set-up correctly.]

[Jeff@TireBalls]

Originally Posted by Charlie-III

Yes, as mentioned, the older AM & FM radios (they also had replaceable crystals for each frequency) had long antennas for both the TX & RX.
The newer 2.4ghz radios have short antennas. They are also a bit more immune to "noise" from the outside, things like the brushes on the motors. That is why you HAD to run caps on the brush hoods to kill most of that noise.

One good thing about AM & FM though, the signal travels through water BETTER than 2.4ghz. So if you run a rig that will spend time in deeper water, you "may" want to keep that radio. It appears that 2.4ghz signals die off if the antenna is more than 1-2" deep in water.

[@ 1r3land..... isn't 27mhz AM & 72mhz FM?]

[@ Jeff@TireBalls, your radio is either ~0.27gz or 0.72ghz if I did it correctly.. Also a lot of the newer radios have the ability to save settings for more than 1 rig, thus easier to swap between rigs without twiddling dials to get things set-up correctly.]

That's good to know. I'm going to run my JR for now and save up for a new one after Christmas.

[Meatwad]

Agreed, antennas are very short nowadays. Ever since going to 2.4, I've coiled up my antenna in the rx box and never had an issue. Unless getting about 30yds away, which is a rarity for this niche of rc.

The cheaper 2.4 radios today aren't bad. 20-30bucks can get a cheap and reliable 2ch radio, if thats the only requirement.

[hpiguy]

Futaba even makes RX's that don't have an external antenna now, known as BIA for built in antenna. Once Charlie-III helped me get them bound to my radio, I love them, and I'm running them in two of my rigs now.

[Olle P]

Some more details on antenna length:

It's based on the carrier wave's length, which is inversely proportionate to the frequency.
A 27MHz wave is ~11m long. The typical antenna used for RC cars is ~35cm (the tube length) or 1/32 wave. If the length isn't exactly 1/32 wave, but a little longer/shorter the reception will be considerably decreased.

For my old Holiday Buggy I use a ~1/16 antenna, which gives good range.


2.4GHz waves are ~12cm i length, and the antennas used are typically 1/4 wave. It's the outer 3cm or so of the Rx's cable that is the actual antenna. It's less sensitive to small variations in antenna length.

I have my antenna (the slightly curved light grey bit) at the rear of the truck, just underneath the body, to avoid interference from the other electronics.

[Johnnysplits]

The receivers I use have internal antennas...nothing sticks out.

[Calderwood]

When I used to race carpet before we had 2.4ghz radios we used to wrap the antenna through a piece of lexan underneath the body like this:

[Charlie-III]

Originally Posted by Calderwood

When I used to race carpet before we had 2.4ghz radios we used to wrap the antenna through a piece of lexan underneath the body like this:

+1.

Kept it away from the ESC and left it stretched out a bit for better range.