I am just wondering what frequency crystals would work on a Smartech 2channel radio system (originally 27mhz. I hooked up 75mhz crystals but they dont work at all. Is there anything i have to do to make them work or does this radio only work with 27mhz crystals. My friend has the exact same car and we want to race, that will never work with the same radio frequency. Any suggestions? Thanks a ton...

A 27mhz radio requires 27mhz crystals to work. It will not, and cannot economacally be made to, work with any other frequency band.
However, there are different channels within the 27mhz band that the radio will work on that will let you race with your friend. The 27mhz band has 6 different channels. They are; A1 - 26.995, A2 - 27.045, A3 - 27.095, A4 - 27.145, A5 - 27.195 and A6 - 27.255. Sometimes those channels are also designated by colors (red, green, blue, yellow, etc) but I don't remember off-hand which color corosponds to which frequency. There is one mre thing thatbyou need to be concerned with and that is that the crystals are compatable with the radio system that you have. Not all crystals are compatable with all radio systems and I don't know who makes the Smartech system. Try taking the radio to a hobby shop and asking if they know what will work or if they would try some different ones in your radio to see.
Hope that helps some and,
Good Luck

THis sure helps a lot! thanks, ill visit the shop asap.