Page 15 - GEN - 2025

2. Frequencies and Frequency Protection

2.1 Frequencies

The frequencies start at 118,000 MHz. Since 2021, it has
been a requirement that there is 8.33 KHz channel spacing

between the frequencies.

However, since there are only 3 decimal places in aircraft

radios, we cannot always set the correct frequency.
In the list here you can see which channel corresponds to

which frequency.

And this continues up to and including 136.990 MHz. start

at 118,000 MHz. Since 2021, it has been a requirement that
there is 8.33 KHz channel spacing between the frequencies.

In order to be able to reuse / use the same frequency for another station, there
must be a reasonably large geographical distance between the 2 stations with

the same frequency. The range depends on the flight height and can easily reach

100 NM.

2.2 Frequency Protection

To avoid disturbing other radio stations, a concept called frequency protection

has been introduced.

Frequency protection is indicated in brackets after the frequency, e.g. (150/50
NM).

This means that you must be within a radius of 50 NM from the radio station and

below flight level 150 before you can call up the frequency.

GEN radio 2025 - Midtjysk Flyveskole 15