I have a Hitec optic 6 transmitter on 35mhz. It has a module in the back which is on a fixed crystal.

My current receiver is a dual conversion one.

I want to buy a couple of single conversion 35mhz micro receivers.

Will my transmitter work with them?

Yes it will provided each of the single conversion Receivers you use has a single conversion type crystal installed on the same channel as your transmitter. You cannot use the dual conversion type crystal from your dual conversion receiver.

John