There are compatibility issues with FM radios and you are always better off using the same brand transmitter and receiver.
There are some instances where you can purchase an aftermarket FM receiver that will work with your transmitter. Airtronics uses a positive shift signal where Futaba/Hitec use negatrive shift so you cannot mix these brands together.
Your Airtronics MX-3 FM transmitter will work with the following assuming you are on 75mHz;
1) Novak Mercury
2) Novak XXL (must buy the Sanwa/Airtronics version)
3) Hitec HFS-03MM (universal)
4) Novak Xxtra (synthasized = no crystal)
5) JR RS300 (synthasized = no crystal)
To use these receivers with your transmitter you must use the Airtronics single conversion FM receiver crystal to match the one in your transmitter. Exceptions are the two synthasized receivers.
If you have a 27mHz FM transmitter the list is pretty much the same as the Novak receivers are also made on the 27mHz band as is the Hitec mode. Again, use the matching Airtronics receiver crystal.
Always do a range check to be sure things are working right otherwise you risk the chance of a runaway car.
Originally posted by lazyeh
Hello, I just baught an Airtronics MX3 radio (seems to be a great intermediate radio!) and it only comes with one reciever...and I was wondering if I have to have an airtronics reciever in my other cars to use the radio or can I use like Futaba recievers?