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Electronics => Electronics => Topic started by: andy b on September 03, 2007, 07:59:08 AM

Title: controller and reciever
Post by: andy b on September 03, 2007, 07:59:08 AM
Can you use a receiver that has a different number of channels than the controller does? And do the controler and receiver have to be made by the same people?
Title: Re: controller and reciever
Post by: airman00 on September 03, 2007, 09:08:13 AM
I'm not sure what youre saying about the channels...
But this should explain r/c.      The controller emits a certain radio frequency and a crystal inside the reciever detects this specific signal. As long as the two perfectly match each other youre fine. But remember its not all 27 mhz. It varies down to the 27.002 mhz.( or it could be a totally different one like 49 mhz)So find out the exact frequency and build everything accordingly. Or you could just buy your own R/C system.

Please post more information so that we may help you.
,Eric
Title: Re: controller and reciever
Post by: crossroads1946 on September 03, 2007, 12:07:27 PM
Airman is right. Manufacturer doesn't matter. Frequency does. Both the transmitter and receiver have to be at the same frequency, and what's more, both have to have to be using the same band in that frequency range. My RC radio, for example, uses the AM 75 MHz frequency (which is what is normally used for ground based hobby radios). There are many other frequencies as well--the 27 MHz frequency is usually used for air based hobby radios, although I've seen some ground based in that range as well. Then, inside that frequency range, both the transmitter and receiver need to be on the same band, which is basically a sub-section of the overall frequency range. This band is determined by the crystal used in both the transmitter and receiver (the crystals will have numbers on them that represent the band). If both the transmitter and receiver use the same frequency and band, they should work. You can NOT put a crystal from frequency A in a radio that uses frequency B to turn it into a frequency B radio... they're the crystals only work with their specified frequencies.

As for your other question... I can't be 100% sure on this without looking it up again, but I believe the standard hobby RC signals use TDM (Time Division Multiplexing) to transmit their signals. That means a pre-determined amount of time is allocated to transmitting and receiving ch 0, ch1, ... ch n. So, for example, if you have an eight channel transmitter and only a 2 channel receiver, the receiver would be receiving the transmitter's channel 0, 2, 4, and 6 signals on it's own channel 0, and the transmitter's channel 1, 3, 5, and 7 signals on the receiver's channel 1.

So short answer, no, I don't think it would work. But I could be wrong.

Baker
Title: Re: controller and reciever
Post by: andy b on September 04, 2007, 09:07:57 AM
Thanks crossroads1946
Title: Re: controller and reciever
Post by: Admin on September 04, 2007, 09:16:55 AM
Quote
Can you use a receiver that has a different number of channels than the controller does?
Yes, definitely. I do it all the time.

Quote
And do the controler and receiver have to be made by the same people?
Sometimes. Ive read datasheets on some receivers that say they only work with certain brands. Check the datasheets to be sure . . .
Title: Re: controller and reciever
Post by: crossroads1946 on September 04, 2007, 09:39:55 AM
I stand corrected. Now I know.

Thanks
Title: Re: controller and reciever
Post by: andy b on September 05, 2007, 11:59:07 AM
thanks for the help youve given me