3 channel radio with 2 channel reciever

[NooP]

Could I use a 3 channel radio with a 2 channel reciever? For example could I use an MX-3 with a standard 2 channel airtronics reciever. Both being am 27.

--NooP

can I use an fm transmitter with and am reciever or vice versa?

--NooP

 

[SkyMaxx]

Yes, you can use a three channel radio with a two channel receiver. The two channel receiver will limit you to using only two servos...as each channel is for one servo.

No, you can not mix AM and FM equipment.

 

[NooP]

how bout 27 and 75?

--NooP

 

[SkyMaxx]

Can't do that either...two completely different animals as far as frequency goes.

 

[NooP]

any advantages to am, fm, 27, or 75?

--NooP

 

[SkyMaxx]

These are all good questions. Here is an answer on the AM vs FM (note that a lot of this stuff can be found by using the search function...which is what I have used to dig up my old posts on this very topic).

Originally posted by SkyMaxx
The real reason for the difference in modulation has more to do with restrictions around the world. Some countries only allow one or the other. Some only allow certain frequencies to be run.

Is AM better than FM? That depends on your frame of reference. AM relies on amplitude modulation which is directly related to the power out of the transmitter. FM relies on adjusting the frequency waveform in within the frequency band you are channelized. This means it works regardless of power supply, but the strength of the signal for both radioes drops as the power supply gets drained. So which is better? I'll side with the FM because the FM will carry a signal more clearly than AM as the batteries drain.
...

As for the 27MHz vs 75MHz, that is a matter of availability, preference, and in certain parts of the world law. I noticed from your profile that you are in Bosnia. You may be limited to only running in one frequency band or another. You may also be limited to a certain modulation type. You may want to check to verify that you are free to choose.

I personally recommend the 75MHz FM radios. You'll find that most RTR and other RC modelers use the 27MHz radios. The 75MHz will buy you fewer conflicts at the track. The FM buys you better signal carriage at low battery power. If you want to go the extra mile, go with a fully synthetic set-up. This will give you some channel diversity and allow you to change channels within frequency without having to change crystals. Costs a little more but is darn convenient when in a race track scenario or area with several RCs running at the same time.

 

[NooP]

I know recievers say 27, 75, am, fm on them, but I dont see any of that on my transmitters. Are transmitters specific to those? or do they just have to have the right crystal in there to match the reciever?

--NooP

 

[SkyMaxx]

That is a good question. Most transmitters (not all...as one out of the four I have does not say what it is) have the frequency and modulation type listed on the casing...or on a sticker on the casing.

If not there, the directions that came with the RC should certainly tell you.

What radio are you looking at?

 

[NooP]

Just asking for general knowledge. Thanx for all the info. Also, I've got 3 cars. Right now, I just need 1 more am 27 airtronics reciever to be able to run them on a transmitter. But soon, when the local track is up, I will upgrade my radio systems. Synthesized are a bit too pricey for me. 200+ for a start system then 100 more for each reciever is too much for me. So I am looking into getting the mx-3. As far as I can see they are only available in FM in either 27 or 75. I been looking around on the net and I could set myself up on all 3 cars for less then 200 which would be nice. Synthesized is just out of my budget right now. I think I know what I want now. Thanx for all the help sky. Anything else I should know or anything you could recommend?

--NooP

Oh yeah, what are these module things? Some of the better radios have modules.

--NooP

 

[SkyMaxx]

Those modules are for running as synthetic radios. They replace the crystal with a tunable module. Then all you have to do is match the receiver crystal with the freq in the module. It is a semi-synthetc set up.

No further suggestions. I think you asked a bunch of good questions and have as much information as you need. The rest is up to what you want and are willing to pay for.

 

[NooP]

ok, another question. Can I run a syntesized radio with a reg reciever or vice versa aslong as the crystals match what is tuned in the module or reciever?

--NooP

 

[SkyMaxx]

LOL...Yes. You can do that. It is not recommended because the crystals and the synthetic tuner might not be a perfect match on a specific frequency, but I have not heard of many instances where that has happened.

 

[NooP]

I think thats about it. Thanks again for all the help.


--NooP

 

[NooP]

can I mix brands? can I use an Airtonics tx with a futaba rx that are both the same in frequency? ALso, do brands of crystals matter?

--NooP

 

[SkyMaxx]

You can mix brands of transmitters and receivers. Just make certain that you have the proper connectors on your servos for the brand of receiver that you use.

The second part of the first question and the second question are very related. First, make certain that the transmitter and receiver are of the same modulation type (AM or FM). Next, make certain that the crystals in both are a match in the frequency.

As for the brand specificity of crystals, you will find that there are two schools on this. The first school (the one I belong to) holds that the brand does not matter. I recommend matching the brands when it comes to crystals though. What I mean, pair your crystals from the same manufacturer. It does not matter if the brand is the same as the radio or recevier.

The other school of thought is that brand does matter and that everything should match. My only fault with this logic is that radio waves are radio waves. If you get a frequency match along with modulation type match, you should be good to go with anything.

The reason I recommend getting crystal pairs from the same manufacturer has to do with a better frequency match from the same manufacturer. In reality, all things being equal, the crystal from one manufacturer should perform the sameway one from another would.

Do not ask me for a brand to recommend. I do not use crystals (full synth on all of my rides), and I would be a poor choice for giving you an accurate suggestion.