Ken has been flying a lot longer than I have, and I always respect his opinion. I'm going to mention some advise that runs contrary to his statement quoted above, however, so take my advice with the caveat that others have been around longer than I.

The GWS RD8SL 8-channel Dual Conversion receiver available from Hobby City for $24.99 is completely compatible with your Futaba dual conversion crystal. There are third party crystal manufactures who make excellent (reputed to be better than manufacturer's original) crystals for major radio brands. I've purchased radio crystals from Performance Devices for Futaba receivers, and they work perfectly. Performance Devices also makes Hitec compatible and JR compatible receiver crystals.

How do I know for certain that Futaba crystals are compatible with the GWS dual conversion receiver? Someone very knowlegable about radio crystals at Performance Devices told me they were. My friend Fred is flying his Thunder Tiger Imagine 50 pattern plane with a GWS RD8SL receiver and a Performance Devices Ch 22 Futaba DC crystal and it all works perfectly together. These $6 Performance Devices crystals have worked just as well for me as the $13 to $17 Futaba DC crystals in Futaba receivers.

As for your receiver, I can't really say RC Ken isn't offering you the best advice. Sending in a receiver and crystal after a crash for service inspection is the best course of action. If you are unable or unwilling to do that, however, a thorough range check with the glow engine running from 100 feet away is the next best thing. There is no guarantee that a receiver or crystal new in the box isn't defective. The 100-foot range check with antenna collapsed and glow engine running is how we check to make sure.

I would fly a plane that passed such a range check with no indication of trouble, other pilots may be more cautious than me. Good luck with whichever course of action you take!