I just bought a Hangar 9 Pulse XT from a club member and he included a HiTec receiver. I use JR for my TX. Should I buy a JR or HiTec receiver crystal?
Indy Park Flyer

Hitec equipment is typically negative shift... although they do make positive shift and auto shift receivers for use with JR and Airtronics. Unless your receiver is labelled "positive shift", "selectable shift", or "auto shift", you probably need to get a new receiver.

What model receiver is it?

I don't have the receiver with me so I don't have the model number, but I know he has used this same reciever with his JR TX in the past, so I know it is compatible.
Indy Park Flyer

If that's the case, then just get the Hitec crystal for your channel #. JR crystals may not work in Hitec receivers (usually best to stick with the same brand receiver xtal).