Mark A. Lacy
Filing Flight Plan
- Joined
- May 4, 2018
- Messages
- 2
- Display Name
Display name:
Skyking
I am a electronics engineer (RF) by trade and having worked in two-way radio for 25 + years and a extra class amateur radio operator of 25 + years I never understood why the aeronautical radio service has remained AM (amplitude modulation) as opposed to FM (frequency modulation).
I understand that AM isn't subject to Doppler effect like in FM but most aircraft operate at speeds less than mach 1, in addition AM isn't subject to the capture effect. This may or may not be a good thing during times there is a stuck microphone or heavy channel congestion.
FM equipment is less expensive, isn't subject to atmospheric noise, man made noise. and the channel bandwidth is much less in addition this would give options like C4FM digital audio.
I see many pro's to migrating to FM.
I've never observed any avionics anomalies while transmitting on FM in the cockpit in either VHF or UHF with power ratings unto 60 watts. Most of the time you wouldn't even need that much power at 8,000', 10 watts should be more than enough.
Several cool options could be integrated into an FM radio system, Automatic ID - Your FAA reg would be transmitted when the PTT is pressed along w/ GPS coordinates and perhaps a status, Including an emergency button.
Switching to FM would effectively triple - quadruple the number of aeronautical channels!
A multi mode transceiver could be produced initially to make the migration more smooth, in other words make a VHF transceiver both FM and AM selectable.
It wouldn't be extremely expensive for a migration to FM because the equipment should be less expensive to produce, a fraction of the cost of ADS-B.
I understand that AM isn't subject to Doppler effect like in FM but most aircraft operate at speeds less than mach 1, in addition AM isn't subject to the capture effect. This may or may not be a good thing during times there is a stuck microphone or heavy channel congestion.
FM equipment is less expensive, isn't subject to atmospheric noise, man made noise. and the channel bandwidth is much less in addition this would give options like C4FM digital audio.
I see many pro's to migrating to FM.
I've never observed any avionics anomalies while transmitting on FM in the cockpit in either VHF or UHF with power ratings unto 60 watts. Most of the time you wouldn't even need that much power at 8,000', 10 watts should be more than enough.
Several cool options could be integrated into an FM radio system, Automatic ID - Your FAA reg would be transmitted when the PTT is pressed along w/ GPS coordinates and perhaps a status, Including an emergency button.
Switching to FM would effectively triple - quadruple the number of aeronautical channels!
A multi mode transceiver could be produced initially to make the migration more smooth, in other words make a VHF transceiver both FM and AM selectable.
It wouldn't be extremely expensive for a migration to FM because the equipment should be less expensive to produce, a fraction of the cost of ADS-B.