airtraffic

Author Topic: Possibly a dumb question regarding line of sight.  (Read 257 times)

Offline Cogspinner

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Possibly a dumb question regarding line of sight.
« on: January 22, 2019, 06:54:12 PM »
I live sort of near a smaller airport and can hear planes talking to the tower but can't pick up tower talking to the planes.  I was just wondering if tower's outgoing stuff is LOS limited?


I'm about 5 miles away and 200' or so lower and there are buildings between us.

(uniden bc125AT with a diamond rh77ca antenna if that means anything)

Thanks in advance.



Offline tyketto

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Re: Possibly a dumb question regarding line of sight.
« Reply #1 on: January 23, 2019, 02:30:13 AM »
I live sort of near a smaller airport and can hear planes talking to the tower but can't pick up tower talking to the planes.  I was just wondering if tower's outgoing stuff is LOS limited?


I'm about 5 miles away and 200' or so lower and there are buildings between us.

(uniden bc125AT with a diamond rh77ca antenna if that means anything)

Thanks in advance.

Yep. You'd be limited by Line of Sight.

My apartment in Las Vegas is 3 miles from KVGT, tucked in between the centerlines of runways 7 and 12R, and I can only hear the pilots from where I am at, and I'm on the top floor. No clear line of sight for me to the tower unless I get to a higher altitude than the buildings between me and the field.

The only way to get around that is to either get closer to the field, or get your antenna to be higher than the buildings/obstructions between you and the receiver at the field.

BL.

Offline Cogspinner

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Re: Possibly a dumb question regarding line of sight.
« Reply #2 on: January 24, 2019, 10:33:46 AM »
Kinda figured.  Thank you for the reply.

Offline dave

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Re: Possibly a dumb question regarding line of sight.
« Reply #3 on: February 06, 2019, 11:47:55 AM »
VHF is not strictly LoS. But whether you can hear the Tower or not depends on several factors:

1) Your antenna type and placement (indoor antennas are typically a non-starter)
2) Distance from the airport and terrain and obstacles between you and the airport
3) Length and type of coax cable
4) Local noise or RF interference that may adversely impact reception
5) Type of receiver (though this is the least important factor typically)

The devil's in the details. Send me a PM if you can provide some details and I can take a detailed look at the RF path and give you a more detailed answer.