FreakyDude, I've read that the typical Heng Long tank over the last few years uses the 27MHz FM frequency chips, while some of the much older ones may have used 40MHz.
I did check both my current HL tanks & the chips do have 27MHz FM printed on them.

01 fm 27 .145
02 fm 27 .195
03 fm 27 . 095
04 fm 27 . 550
05 fm 27 . 245
06 fm 27 . 295
07 fm 27 . 345
08 fm 27 . 600
09 fm 27 . 650
10 fm 27 . 680


~ Craig ~