reciever xtals are confusing as hell!!

[bigboystoysguy]

ok my mamoth came with the hitec agressor 2ch controller, its an am controler on 75mhz, wtf?? then the traxxas tq radio is an am radio on 27mhz again I'm confused as hell. then my m-8 is fm 75 mhz. is there an am and fm 75mhz and an am and fm 27 mhz??

 

[mcvickj]

Yes there is a 75Mhz AM and FM and 27Mhz AM and FM.

https://www.rcnitrotalk.com/forum/showthread.php?s=&threadid=15127

 

[Candyman]

Yup, confusing as all hell. There is an AM and FM on 75 mHz. But I believe 27 MHz is only AM. Frankly, I'm trying to sort it all out myself. I wonder, can an AM radio on channel 61 (75.410) run at the same time as an FM radio on channel 61?

 

[mattyk6]

Nope, there is a 27 Mhz FM.

 

[Candyman]

Well great. That just makes it even more confusing. So can FM and AM run on the same channel without interfering since they are different modes of transmission?

 

[SkyMaxx]

You will still get interference if the transmitters are relatively close. The channel is more of a carrier frequency. The information is put onto that frequency by either modulating the frequency (FM) or modulating the amplitude of the pulse (AM). So in close proximity you will still get interference. FM tends to run a little farther and consistantly so. AM tends to start with some decent range, but as the batteries get weaker that range moves in. The other side of the coin is that lower frequencies tend to go greater distances. So the 27MHz AM on fresh batteries should have the greatest range, then the 27MHz FM...and so forth and so on.

 

[militarymaxx]

Yup, Sky is right (as usuall). I got into an argument the other day with a guy that was convinced that even though our freqs. were the same, they wouldn't interfere because his was AM and mine FM. So, I told him that if he was that confident, then turn on his buggy, run it full tilt in the parking lot and let me turn mine on. He got to thinking and wisely agreed to further educate himself on the subject. A freq. is a freq. is a freq. Modulation on the other hand is something different.

 

[zoeybadm]

Originally posted by militarymaxx
Yup, Sky is right (as usuall). I got into an argument the other day with a guy that was convinced that even though our freqs. were the same, they wouldn't interfere because his was AM and mine FM. So, I told him that if he was that confident, then turn on his buggy, run it full tilt in the parking lot and let me turn mine on. He got to thinking and wisely agreed to further educate himself on the subject. A freq. is a freq. is a freq. Modulation on the other hand is something different.

Yeah some idiot was racing at my local track and ran my car straight into a pole 15ft off the ground at full throttle of a big jump. The guy swore his rtr AM radio would never be able to cause problems with my 75Mhz FM radio and I explained it to him in detail but the guy still did not get it and I told him if he did not pull his car off the track and turn his radio off his car would glitch.

He did not listen and roasted his motor as a result....I warned the guy but some people just do not listen to people younger than themselves....

 

[bigboystoysguy]

that is so retared!! why can't it be am27mhz and fm75mhz and then fm72mhz for air vehichles preiod thats it no more no less but no, we gotta mix it up a little so when you truck says channle 61 on the box, you think wow, an fm radio in an rtr, very nice then you open to find an am radio!! that sucks!! it should be a little more strait forward.

 

[Rolex]

I just changed the crystals on my Tmaxx to brown. That's 26.995
The frequencies that airplanes and cars run on was GIVEN by the FCC just for that purpose. That's why you don't need a license to run them. If someone is on red, and someone else is on blue or whatever, there will be a bit of "signal bleed" if they get too close to the other car, causing some servo twitching. Step back just a few feet and it will stop. We're on narrow bands, but as long as you have different frequencies, there shouldn't be a problem.