Radio Principles Flashcards
what is frequency?
rate of recurrence of a vibration, oscillation or cycle.`
what is CPS?
Cycles per second
What is 1 CPS equal to in Hertz?
1 CPS = 1 Hertz
What is 1,000 CPS equal to in Hertz?
1,000CPS = 1,000 Hz or 1 Kilohertz (KHz)
What is 1,000,000 CPS equal to in Hertz?
1,000,000 = 1,000 KHz or 1 Megahertz (MHz)
what allows radio waves to travel through space and most materials?
due to their electric/magnetic field status
Is distance covered by sound waves greater than radio?
No
How fast do Radio Waves travel?
Speed of light
what does HF stand for?
High Frequency
What is the HF range?
3 - 30 MHz
What does VHF stand for?
Very High Frequency
what is the VHF range?
30 - 300 MHz
which frequency is preferred for long-distance and the other for Aviation?
HF = long VHF = aviation
why is VHF used for aviation?
because the greater amount of frequencies within the band, allow for a great range of available frequencies in support of the numbers of services required.
Why is the reception of VHF comms superior to HF?
due to the lower frequencies being more prone to interference from various sources, e.g atmospheric disturbances
what are the disadvantages to VHF?
the inability of signets to bend around objects such as mountains.
What are transmissions referred to as?
Line of sight
why are transmissions referred as it is?
because of the disadvantages of VHF
In terms of comms what are most aircraft fitted with?
handheld and boom mics with handheld substituting as a 1backup.
FM or AM for microphones?
FM normally
What is squelch control?
a control used to eliminate unwanted signals such as static
When is squelch control used?
when flying towards the limit of reception, can be fixed by adjusting the squelch control knob to the position of where extraneous noise is minimised.
What is the RADIO NOT WORKING simple fault finding procedure process? (8)
- Check master switch and optionally avionics master is ON
- Check radio ON?OFF set to ON and with NAV/COM set, make sure proper side is on (NAV side ON instead of COM)
- Check correct settings on the audio selector panel if fitted.
- Check circuit breakers or fuses.
- Check all connections such as microphone plug, and if using headphones check if they’re plugged in properly
- Check correct frequency has been selected and double-check the frequency set to COM.
- Check volume control is up
- Check squelch control is not fully anti-clockwise.p
What are the additional radio equipment in aircraft?
two additional radios, ELT and the Transponder
What is a transponder?
a device for receiving a radio signal and automatically transmitting a different signal
what allows transponders to do?
allow for a ground-based radar controller to determine the location and sometimes altitude of aircraft.
What can the info off transponders do?
Can be obtained by pilots with an Airbourne Collision Avoidance System (ACAS) to ascertain the position of other aircraft equipped with transponders.
what is TM?
Transponder Mandatory Zone.
What does TM require?
require aircraft to be equipped with a functioning transponder.
what happens if an aircraft doesn’t have a transponder equipped in a TM?
maybe permitted by ATC in certain situations and must append the words “NEGATIVE TRANSPONDER” to the request.
How is Transponder Mandatory Zones identified on NZ visual aeronautical charts?
by the letters TM.`
On the NZ visual aeronautical chart if it shows a box with:
- A Captial C
- 2500 / SFC
- WN 118.8
- TM
What do they mean?
C = Class C Airspace
2500 / SFC = Surface - 2500 Feet Uncontrolled since its a Class C Airspace
WN 118.8 = Wellington 118.8 Frequency
TM = Transponder Mandatory Zone.
What do OFF, ON, SBY(Standby), ALT(Altitude), and TST mean on transponders?
OFF = transponder off SBY = Stand-by, transponder on, but won't reply ON = transponder on and will reply to interrogation but only Mode A info. ALT = transponder on and will reply, both info sent. Can see altitude and position. TST = Transponder Test Function.
What are the 3 important emergency codes?
7500, 7600, 7700
What does 7500 mean?
Unlawful interference (Hijacking) 75 let the other guy drive
What does 7600 mean?
Comms failure, 76 Radio needs a fix
what does 7700 mean?
emergency (Distress) 77 pray to heaven.
what does SQUAWK IDENT mean?
must press transponder ident button once, allows controller to identify aircraft.
