20 years too late. lot of us give up, declare the bathtub is a no fly zone.
only rc sub guys still using them, not too many of us giving them up. finding crystal is a headache. they stop making them 20 year ago.
forget about 27MHz, it is even harder to find. there is some new info about a DIY.
433 MHz! it works under water, if you ask a HAM guy, it is also in the gray area. and china stop making them.
there is a way to make a 72 to 75, one is in the gray area (PM me), best one is get a good condition 72 set and a set of 75MHz crystal to a shop to re-tune.
other, if you can find a 75MHz RF module {Futaba,Hitec,JR, Novak, no airtronic} from a rc car guy.
https://subcommittee.com/forum/showt...-radio-systems
info
2.4GHz go around.
https://forum.rc-sub.com/forum/gener...r-c-submarines
sorry, is all over the place, will add 12/16 channel RX up date sometime. very light gray AREA.
https://forum.rc-sub.com/forum/gener...hz-transmitter