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Old 08-02-2009, 03:40 PM   #1
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Default Radio Question - AM vs. 2.4gig?

Looking for opinions out there on my dilemma - should I keep my MX-3 AM radio (for which I have all twelve freq crystals) or spend $$$ and get a new 2.4g?

I race in the TC 17.5 rookie class, and I want to take it seriously and do well, but is there a performance advantage I would get with the 2.4 that would justify the price? Is the 2.4 'faster' to respond and is it noticeable? Faster but not really noticeable?

Feels like I am having to start turning in advance of the corner to make it and I don't know if that is normal or is it that my AM radio and HS-625 servo too slow for racing?
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Old 08-02-2009, 03:54 PM   #2
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Isn't that an FM radio?

Many people including myself still prefer FM.
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Old 08-02-2009, 03:59 PM   #3
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There is no real performance advantage between AM, FM, or DSM (2.4 gHz) radios. The advantage of 2.4g is no more crystals, and no frequency conflicts.

Save your money and work on handling.
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Old 08-02-2009, 04:11 PM   #4
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A good high speed servo will benefit you alot more than switching radios. As long as your radio has the basics: reversing, endpoints, dual rates and even curves/expo, you should be fine with that.

KO, JR, Airtronics and Futaba are the best servos out there, they center well (which is huge) and have great holding power, speeds and torque depending on which model you choose. That's one area where you should not really skimp on if you want to not have your equipment hold you back.
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Old 08-03-2009, 12:37 PM   #5
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On thing to consider if using an AM system is that many RTR r/c cars come with AM radios. If you race at a track with a lot of novice racers, they may not always understand about radio frequencies and could create interference with your system. However, you have extra crystals so that shouldn't be an issue.

The only down-side to an AM system that I can see is that you really have to run the antennae outside the body to get good reception. The newer systems don't have this limitation.

To repeat the previous post: if your radio has end point adjustment and dual rates, there is no reason why you have to upgrade to new systems.
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Old 08-03-2009, 01:27 PM   #6
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Just curious, am I correct in assuming that AM and FM on the same channel do not interfere ?
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Old 08-03-2009, 02:38 PM   #7
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Quote:
Originally Posted by imjonah View Post
Just curious, am I correct in assuming that AM and FM on the same channel do not interfere ?
You are incorrect, they will interfere, but an AM radio cannot control an FM receiver etc.

To the OP - as long as you are not getting interference and you are happy with the feel and settings on the radio, there is no need to change. Slow response is probably partly psychological, partly the Hitec servo. Personally speaking I have no intention to switch from FM to 2.4, the radio works 100%, and I rarely have to worry about crystal clashes any more either!
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Old 08-03-2009, 02:54 PM   #8
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Quote:
Originally Posted by Micro-E View Post
Looking for opinions out there on my dilemma - should I keep my MX-3 AM radio (for which I have all twelve freq crystals) or spend $$$ and get a new 2.4g?

I race in the TC 17.5 rookie class, and I want to take it seriously and do well, but is there a performance advantage I would get with the 2.4 that would justify the price? Is the 2.4 'faster' to respond and is it noticeable? Faster but not really noticeable?

Feels like I am having to start turning in advance of the corner to make it and I don't know if that is normal or is it that my AM radio and HS-625 servo too slow for racing?
The only performance issue that I can really think of is that AM radios are more likely to be affected by outside sources like, power wires, radio antennas, underground pipes, motor noise, etc. Before switching to 2.4 I had to do all kinds of things to ward off the glitches from outside sources.

This may not be completely true, I'm no scientist but, listen to an AM radio, then listen to an FM radio, then listen to digital radio. You can hear them all just fine but, the level of noise or interference decreases the farther you get from AM.

That said, if you have no problems with glitches, there's no reason to switch right away. Chances any problems you are having with steering is the servo or setup.
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Old 08-03-2009, 02:55 PM   #9
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Thanks for the replies everyone. As long as there are no performance differences (sounds like their is none) I'll keep the AM. Not so worried about the ant sticking out of the body, and I have NEVER run across anyone else who has AM 10,11,12 for a freq. Until I see a conflict, I'll save the dough for something else.

Thanks all!
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