UHF vs VHF air

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jaymatt1978

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Let me preference this post with I know the difference between AM and FM transmissions, I also know the difference between signal strength and audio. This being said I have been finding the audio on the UHF air band louder than the VHF band, Since moving to Cape May I've heard a lot more military air.
 

eorange

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Let me preference this post with I know the difference between AM and FM transmissions
Not sure why you're pointing this out, because the VHF and UHF airband is AM, not FM.

Anyway, I've found the opposite to be true...VHF military air transmissions seem to be punchier than UHF.

And it's not a distance thing...I've monitored AR tankers as I watched them fly right over my house, and the UHF signal is solid, but even. VHF mil air for fighters (which I haven't seen) seem way louder.
 

majoco

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Insufficient info. Same radio? Same antenna? Aircraft distance and altitude? Same aircraft transmitter and power? Position of antenna on aircraft?

Too many variables and don't knows.
 
D

DaveNF2G

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Signal strength and "volume" of the received signal are more closely related in AM mode than in FM. A nearby or more powerful AM transmitter will sound "louder" to your receiver than one that is further away or weaker.
 

jaymatt1978

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Ok I understand but aren't the ATCC VHF and UHF frequency pairs transmitting off the same antenna? Like the Sea Isle VHF frequency 133.125 and UHF frequency 281.4500. 281.4500 comes in LOUDER
 

eorange

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Ah, well, I was referring to airplane transmissions. I don't live close enough to any ARTCC towers to pick them up.

Although, once I drove to a VHF RCAG just to hear the tower side, and it was loud, but I was also right next to it LOL.
 

nd5y

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Most RCAGs have several towers with several antennas on each tower. They don't have VHF/UHF on the same antenna.
The type of receive antenna you have, the difference in VHF and UHF, and the transmit antennas not being in the exact same location can make a difference on how well you hear a particular transmitter.
 

nr2d

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I heard the same thing sometimes. It depends on the aircraft but I think that the UHF radio in the aircraft amy use a bit more audio compression plus the fact that the fighters that you might hear the microphone is in the O2 mask where as the VHF aircraft, civil and military, most likely are using microphones that are either headsets or handheld. Not too many handheld mics are used though. Just a thought.

BTW both frequencies main transmitters for ATC are located at the Atlantic City airport.
 
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