Here is a state side supplier of 27 Mhz FM crystals that work with Heng long tanks. I have tested these and they work fine, You need the 27 Mhz FM F type crystals, and he has 12 different channels available. (Look for the Japan Futaba crystal set on the web page) Some of these of course duplicate the HL crystals. Also order them by the frequency not the channel number, A channel 1 in HL might be a channel 6 in these, so just because you have channels 1-4 in a Heng Long crystals doesn't mean you just order 5-12 in these.

I think he is selling these for about $7.50 a channel


[link=http://www.performancedevices.com/27_and_29mhz_am_and_fm_sets]Sport crystals[/link]