Two steps to a better receiver range.
Step one:- tweaking your antenna to its resonant frequency. For example, your transmitter is on 72.69Mhz:-
300 / 72.69mHz.
Divided the result by four.
Prune your antenna to this length.
300 divided by 72.69 = 4.127 metres length.
Divide 4.127 by 4 = 1.032 metres = 1032 millmetres = 40.63 inches.
Step two:- use a heavier gauge antenna wire.