I made a discovery today...
Futaba crystals do NOT work in Hitec 40mhz radio gear.
Hitec receiver (single conversion) works with Futaba Tx (although 665 seemed glitchy, 775 was faultless)
Jeti (cheap) receiver also seems to work with futaba Tx, but is even glitchier on 665.
(Guess who's Futaba receiver died on a damp track...)