What is Hi- band Low-band?
Most receivers are tuned to the center of the band and can use any crystal within the band. Early JR and current Futaba receivers have their front ends tuned to the center of either the high-band or the low-band. The low band is channel 11 thru 35 and high-band is channel 36 thru 60. On these unit only a crystal within the sub-band should be used.