Originally posted by smchale
ok...my head is spinning here :spinnyeye
so, if i have a rx and tx on channel 25 and I crash the plane and damage the crystal in the rx, I can't take a crystal out of a rx on channel 15 and take the crystal out of the tx on 15 and swap it with that one that was on 25 and go flying? same radio, same reciever, just 2 new crystals. what if I buy a new set of crystals on 25...Can i put these in and go flying?
You are allowed to change the crystal in the receiver to match the transmitter, but not change the transmitter crystal to change the channel.
This is partly because just changing the crystal in the transmitter doesn't necessarily complete the move to a different frequency, as it might take a little tuning in the RF output to get it exactly right. The channels we use are very narrow band, and any compromise in the output frequency might bleed over to an adjacent channel.
If some form of module is used (e.g. the Spectra in the Hitec) then it's quite OK to change the channel, but that's because these modules are not just simply using a different crystal.
Actually the frequency stated is the superhet frequency, which is a more complex process of transmission than just creating the frequency for the receiver crystal to respond to.
But that's a subject for another thread!
David C.