RTC – MOD-02 – Pt.08 – Transmitting Techniques Frequencies
Within radio, there are a lot of bands and techniques but there are mainly 3 bands used in DCS:
- FM (30 MHz to 76 MHz)
- VHF (118 to 137 MHz)
- UHF (225 MHz to 400 MHz)
The rules
So here are the 3 rules when it comes to saying frequencies on the radio:
- If it is FM/VHF, all digits and the decimal are spoken (3 digits, decimal, 3 digits)
- If the FM/VHF has .*00 behind the decimal i.e. 124.100, it will be abbreviated to 124.1 (3 digits, decimal, 1 digit)
- If it is UHF, the last digit is never spoken. (3 digits, decimal, 2 digits)
examples
VHF Fq 134.120 – “Frequency one three four decimal one two zero”
VHF Fq 120.025 – “Frequency one two zero decimal zero two five”
VHF Fq 118.100 – “Frequency one one eight decimal one” (118.1)
VHF Fq 122.000 – “Frequency one two two decimal zero” (122.0)
UHF Fq 255.400 – “Frequency two five five decimal four zero” (255.40)
UHF Fq 236.525 – “Frequency two three six decimal five two” (236.52)
The explanation
Within the FM and VHF ranges, the steps between frequencies can be as little as 0.00833 MHz. This means that the last digit of a VHF frequency is significant. When it comes to UHF, the steps between frequencies are 0.025 MHz. Because of this, the last digit becomes standard. The frequency is always on either .*00 .*25 .*50 or .*75. This is why the last 0 or 5 is implied. So respectively, these numbers become .*0 .*2 .*5 .*7. It is expected that pilots know this when entering the number into their radio, that someone says 236.52 means 236.525 needs to be entered into the radio.
What is expected
In 11TSG we expect the pilots to be able to apply the 3 rules in the beginning of this chapter. This means being able to identify a FM, VHF or UHF band spectrum based on the frequency, and to know then how to transmit it over the radio.