These radio controls are used in industrial applications that require extreme ruggedness and environmental robustness.
This belt mounted 1/4 watt transmitter .is water proof and tested for a 4 foot drop on concrete. It includes tone encoding with thousands of unique combinations and a signal speed ot 10 per second
The receiver is shock mounted against vibration. Input power is regulated from 40 to 10 volts DC. There is a crystal filter and preamplifier on the antenna input for adjacent channel rejection.
This tone encoder scheme uses a crystal stabilized oscillator to generate
frequencies as close as 30 Hz spacing. Multiple tones in an ordered sequence
is used to provide very fast signaling within a narrow bandwidth