Emergency Frequencies
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From: Matrix
Emergency Frequencies
The above frequencies stated in my ATPL manual are 121.5MHz (VHF) and 243MHz (UHF).
I'm puzzled... why would 243MHz be in the UHF frequency band when UHF starts from 300Mhz??
AO
I'm puzzled... why would 243MHz be in the UHF frequency band when UHF starts from 300Mhz??
AO
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From: The wx is here, I wish u were beautiful
Aviation UHF radio straddles the spectrums (225MHz-400MHz).
Multiply 121.5 times 2....243.0. The base oscillator circuitry for carrier generation can be interchangeable, with only the divider circuitry changed between the two bands.
Multiply 121.5 times 2....243.0. The base oscillator circuitry for carrier generation can be interchangeable, with only the divider circuitry changed between the two bands.
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airman13, how are you going to make your mayday call on 406MHz?
Be careful of generalisations. I think you'll find that Emergency Locator Transmitters will have to operate on 406MHz from Feb 2009. The change is being made, in part at least, so that 121.5MHz remains clear for voice transmissions rather than suffering interference from ELT broadcasts, many of which (the vast majority, I believe) are 'set off' inadvertantly or in error.
Be careful of generalisations. I think you'll find that Emergency Locator Transmitters will have to operate on 406MHz from Feb 2009. The change is being made, in part at least, so that 121.5MHz remains clear for voice transmissions rather than suffering interference from ELT broadcasts, many of which (the vast majority, I believe) are 'set off' inadvertantly or in error.
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From: The wx is here, I wish u were beautiful
Right On, Spitoon
406 MHz is an international SAR frequency, primarily for beacons...and one reason is that all the new satellites used for SAR have 406 MHz receivers. Lower transmitter power and smaller antennas.
And you would never xmit VOX on 406MHz, as aviation UHF radios only select up to 400MHz. (Of course, with an old vacuum tube monster, you could cheat it a bit out of band.)
And you would never xmit VOX on 406MHz, as aviation UHF radios only select up to 400MHz. (Of course, with an old vacuum tube monster, you could cheat it a bit out of band.)
Joined: Dec 1999
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From: UK
However, 121,5 will be replaced soon by 406 Mhz, it seems to be started 1 feb 2009.
Joined: Jun 2005
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From: AEP
For the "I know everything" nerds
VHF emergency civilian 121.5 mHz R/T
UHF emergency military 243.0 mHz R/T
MF emergency frequency 500 kHz. (it is in "the book", no idea how is used)
HF emergency frequency 2,182 kHz AM or USB R/T
UHF emergency beacons 121.5, 243 and 406 mHz.
xxx
Of interest to you - merchant marine vessels, at high seas, monitor -
HF general call frequency ship-to-ship 4,125 kHz USB (night)
HF general call frequency ship-to-ship 8,291 kHz USB (day or night)
HF general call frequency ship-to-ship 16,590 kHz USB (day)
Most ships have D/F capability on these. Can give your QDR...
xxx
Happy contrails
P.S. I was an active "radio ham" in the old days...
When bored on oceanic flights, sometimes played with these HF freqs...
UHF emergency military 243.0 mHz R/T
MF emergency frequency 500 kHz. (it is in "the book", no idea how is used)
HF emergency frequency 2,182 kHz AM or USB R/T
UHF emergency beacons 121.5, 243 and 406 mHz.
xxx
Of interest to you - merchant marine vessels, at high seas, monitor -
HF general call frequency ship-to-ship 4,125 kHz USB (night)
HF general call frequency ship-to-ship 8,291 kHz USB (day or night)
HF general call frequency ship-to-ship 16,590 kHz USB (day)
Most ships have D/F capability on these. Can give your QDR...
xxx
Happy contrails
P.S. I was an active "radio ham" in the old days...
When bored on oceanic flights, sometimes played with these HF freqs...
Joined: Sep 2007
Posts: 263
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From: inside of a pretty bustard
Hi BelArgUSA,
Nice to see you mostly on those threads wich need a piece of advice from an ''old bird of the sky'' , I think you will not be upset for this compare, but , I have a few questions.....do you think in a new era of a supersonic flights? .....do you think the airline industry will be affected by the global recession?.....will the global alliances survive in the coming years? ....thank you !
Nice to see you mostly on those threads wich need a piece of advice from an ''old bird of the sky'' , I think you will not be upset for this compare, but , I have a few questions.....do you think in a new era of a supersonic flights? .....do you think the airline industry will be affected by the global recession?.....will the global alliances survive in the coming years? ....thank you !
Joined: Jun 2005
Posts: 1,420
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From: AEP
Airman13 -
xxx
Excellent idea for a subject to debate in another forum.
Suggest you do start it in "Airline, airports and routes"...
I will join in with my usual "old fart" ideas from last century.
Would be better there than under a label of "emergency frequencies".
Here, all that is suitable is mentions of Morse Code SOS.
Did did did, dah dah dah, did did did, was it...?
xxx
Happy contrails
xxx
Excellent idea for a subject to debate in another forum.
Suggest you do start it in "Airline, airports and routes"...
I will join in with my usual "old fart" ideas from last century.
Would be better there than under a label of "emergency frequencies".
Here, all that is suitable is mentions of Morse Code SOS.
Did did did, dah dah dah, did did did, was it...?
xxx
Happy contrails
