This article is from the Radio Control (R/C) Flying FAQ, by Shamim Mohamed email@example.com with numerous contributions by others.
Strongly recommended! A "1991" system is so named because in 1991 the
radio control frequency regulations changed, which effectively made the
"old-style" radios unusable. The "old-style" radios have a separation
between channels of 40 kHz. Today, a separation of 10 kHz is needed, even
though R/C channels will still be 20 kHz apart---because the FCC in their
infinite wisdom have created channels for pagers and such _between_ the
R/C channels, i.e. 10 kHz away from our frequencies. The Airtronics VG4 FM
series is an inexpensive example, and is about $120 mail order. [U. S.
If you can afford it, a system that has a "buddy box" is a really good
idea. This is an arrangement where the instructor's radio is hooked up to
yours, and he just has to release a button on his radio to take over
control, rather than wrestling the radio from your grip. If you do this,
be aware that you need to get the same (or compatible) radio as your