VHF Flashcards
What is RT or RTF
the use of radio between aircraft and ground stations to obtain info and instructions needed for the safe conduct of a flight operation
what are the 2 types of VHF frequency ranges
VHF BROADCAST (AM & FM)
88-107.95Mhz
VHF NAV (AM & FM)
108 to 117.975Mhz
for navigation (VOR or Instrument landing systems), or one way transmissions of info from ground station to aircraft
VHF COMMS (AM)
118-136.975Mhz
for voice comms between Aircraft and ground stations
VHF use how far from ATC
usually within 200NM from ATC tower
Channel spacing standard is..
In most part it’s25KHZ
Ex:
118.025Mhz
118.050Mhz
118.075Mhz
…
760 distinct frequences possible between 118 & 136.975Mhz with a 25KHz separation
Usually the channels have 5 digits
However, over Europe, the channel spacing is now…
8.33KHZ above FL 195)
(to avoid frequency overlap in high traffic airspaces)
There is now 2000+ distinct frequencies between 118 & 136.975Mhz
aircraft must be equipped with 8.33 Khz radios
channels require 6 digits
Phraseology of the frequency
A) if after the decimal, the number ends in 2 zeros, you read the first number after the decimal
119.000 = wun wun niner decimal zero
124.600 = wun two four decimal six
B)all other numbers to be read in full.
129.250 = wun two niner decimal two fife zero
130.425 = wun tree zero decimal four two fife
Let’s say you have a 5 digit display radio
If you are passed a 4 digit frequency - what do you set?
put all four numbers, plus zero at the end
Verbal 124.5
Radio setting: 124.50
If you are passed a 6 digit number - what do you set?
Put all 5 numbers and ignore the 6th
Verbal 124.567
Radio setting 124.56
Regardless whether you fly in or outside europe, how should you read the frequency number
It should be read back the way ATC has called it.
Let’s say you have a 6 digit display radio
If you are passed a 4 digit frequency - what do you set?
put all four numbers, plus zero zero at the end
Verbal 124.5
Radio setting: 124.500
If you are passed a 5 digit frequency - what do you set?
put all five numbers, plus zero at the end
Verbal 124.56
Radio setting: 124.560
Dual frequency selection VHF radio
One that allows use to set the frequency in use
+
set a standby frequency (one you will use next after ‘frequency in use’ is done with’
then you press the change over button and it swaps the two around. This means you will need to set a new ‘stand by’ frequency
Single frequency display VHF radio
allows you to store up to 4 commonly used frequencies in memory
Intercom System
A system that allows crew members to communicate in an aircraft
Notes:
1) adjusting the Intercom system is independent of the Radio System
2)ajdust them both before take-off
3)Radio comms should be priority and should be heard above the intercom
Squelch control
a switch or knob on your radio
filters/mutes the white hissing noise produced when receiver’s audio output isn’t receving signals
What is FM and AM
FM = Frequency Modulation
AM=Aeronotical Mobile Service Voice Communication
VHF - Comms uses AM Only
VHF - Nav uses AM & FM
What is HF
High Frequency
Used for long distance voice communication
(longer than VHF)
