hardlanding7

I have a Tower Hobbies transmitter and reciever, and my brother has a JR Quattro Tx and Rx, both on channel 48. I know that JR and Tower Hobbies (as well as Futaba) work in different ways, even though they are on the same channel. I tested to see if his plan would pick up on my Tx's signal, and it didn't, but I'm still a little curious and worried. Is it possible for them to cause any interference with each other? I would hate to lose a plane thinking that they don't bother one another, and then watch it plunge into the ground.

polstery

This post is a joke RIGHT??

bhole74

Don't even try it!

Kmot

My Feedback: (24)

If both radios are on Channel 48 but one is AM and the other is FM they may not affect each other directly when you test them but chances are very good they will affect each other if you try to fly together so don't risk it.

hardlanding7

No, it's not a joke at all. They are both FM. And I am trying to refrain from calling you some very rude names right now. I think the whole point of a board like this is to check these things. I'm not stupid. I checked it very thouroughly before flying either plane, and still have not flown either of them with both radios on. When I did the ground check, the TH did not seem to cause interference with the JR, and vice versa, but I still am not going to fly them together.

In case you didn't know, JR and Futaba/Tower Hobbies' systems have a totally different way of transmitting signals. A channel 48 for a JR is not the same as a channel 48 for a TH/Futaba. That's why you can't use a JR system with a TH/Futaba buddy box.

Kmot

My Feedback: (24)

Positive shift and Negative shift versions. Still sketchy, I would avoid it.

crashawk

the old am systems used an on/off pulse to send the info to the reciever, fm does a similiar thing but instead of on/off it uses on/shift to one side pattern. in otherwords if your freq is 72.150 it will transmit at that freq then shift either pos or neg to a freq just a hair to one side of 72.150 then back again repeating the pulses thus neg shift transmits at freq and at lower freq while pos shift uses the main freq and higher freq. since both radios use the same freq but different shifts they only see one half of the other radios signal. may not interfer up close where both radios are strong but get some distance between the radios and the recievers and the recievers will try to listen so to speak to the strongest signal and since that signal won't be complete for it, it will (to put it simply) MESS UP.
[:@]

that's why any old am system will work with any other am system but fm has to be same positive or neg shift to work together, and all three (am and both fm shifts) will definately interfer with each other. my advice is don't try to fly both planes at once, please. hope this helps.

Jason

crashawk

In case you didn't know, JR and Futaba/Tower Hobbies' systems have a totally different way of transmitting signals. A channel 48 for a JR is not the same as a channel 48 for a TH/Futaba. That's why you can't use a JR system with a TH/Futaba buddy box.
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I wouldn't say totally different, I hope my first post helped but I think I need to make sure that you know they share the same freq exactely, the part of the signal that would be off on an am system is just shifted pos or neg on an fm system, so just one half of the "code" the reciever sees is different for your two radios, the other half is the same.

think of the signal as mores code and the dots and dashes the operator hears are part of signals message, the quiet spots between the dots and dashes is info as well, long or short quiet is just as important (long quiet spots mean spaces between words etc.) so the dots and dashes would be the freq that the two different fm systems share or use alike and you should be able to see how that could cause interfenence between your two radios since the reciever listens to the strongest signal in most cases.

Jason

Geistware

My Feedback: (16)

I had someone with a JR radio on Channel 23 not affect my plane using Futaba equipment on channel 23. We did test it in several ways (range test) and found that while our ground range was cut in half, the only time we had zero range was when his transmitter blocked my line of site and visa versa.

THis was all done with a collapsed antennae. Extended the results may be different but I would recommend never to fly two models on the same channel regardless of the equipment mfg.

Azcat59

Electronic advice notwithstanding, I sure wouldn't try to fly two planes on the same channel. The liability exposure is enough to make one shudder.....

Clair

MyWay

Somebody please explain the reason why frequency pins are commonly used. Im missing somthing here.

DBCherry

My Feedback: (4)

They WILL affect each other. Maybe not constantly, but enough to cause planes to crash.

As Jason said, they will essentially see half of every input.
Dennis-