I'm working on a quadcopter and have some questions about the receiver and transmitter. I'm going to be milling the boards myself and wanted to know what would be a good carrier frequency to use. I was planning on 10 MHz but I'm not sure if it's better to go higher or lower? I also have the basic block diagram laid out and was hoping if someone could give it a once over and let me know if I'm missing anything. For the modulator block I was going to use the SA605 chip.
It's better to go with something that you're allowed to use. That depends on your region. A shortlist follows (source):
- USA/Canada: 72 or 2400MHz.
- Europe: 27, 35, 40 or 2400MHz.
- UK: 459MHz.
- Singapore: 72 or 2400MHz.
- China: 1400, 2400 or 5800MHz.
- Australia: 27, 29, 36 or 2400MHz.
- New Zealand: 27, 29, 35, 36, 40, 72 or 2400MHz.
Even within these bands there are often restrictions, so best to check. You also want to make sure you're doing something to both tolerate interference and not cause undue interference.
After all that is said and done, then you can worry about which is better. Roughly speaking, lower frequencies carry further but need a bigger antenna. Higher frequencies attenuate more but can have a higher data rate. You have to make a trade-off.