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Author Topic: FM Radio Reception while airborne  (Read 926 times)

Offline NO2CW

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FM Radio Reception while airborne
« on: December 13, 2016, 1842 UTC »
Not sure if this has been discussed before but I made a bunch of recordings from FM stations received while flying at 35k feet. I have posted the videos on youtube and tried to annotate them as much as I can. Just about every frequency has several signals battling with one taking over from another as you fly.

Fort Lauderdale to Dallas to Albuquerque:

http://youtu.be/0wiXJfbhdmE

Several flights between New York JFK and Miami:


http://youtu.be/FBLQsqdQUfk

http://youtu.be/czqkVjaSG5o

http://youtu.be/8lZUnhMAbGQ

http://youtu.be/4xcrrVoqzCk

Offline ThaDood

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Neat!!! I've wondered what that would be like to take an FM RX up on a plane with you. Back in 1988, as a birthday gift, I got a 30min local plane ride over the famed ex-P.O. drop of P.O.Box 452-land. However, instead of an FM radio, I took along one of those Citizen pocket-sized LCD B&W TV. That, and my Dad bummed me his camera to take PIC's of areas of interest. Anyway, most hilltops there are about 2,400ft ASL, and I believe that we, (Myself and the pilot.), were about 3,000ft above ground. The pilot wouldn't allow me to extend the TV's antenna, so with a retracted 3" antenna, here's what it received. All of the county PBS UHF TV translators for WNED-TV, Buffalo. That's UHF. On VHF-high, only thing RX'ed was Buffalo's CH7 WKBW-TV CATV quality.  Nothing else, like CH11 CHCH-TV, or any of the Rochester, NY stations. On VHF-low, nothing, not even a hint of Buffalo's CH's 2 and 4. Still, a neat experiment. Makes me only wonder what I would have RX'ed if I was allowed to extend the telescopic whip, or even stick it out the window.
From DC to light, I take a huge spectrum bite!

Offline MojaveBeaconeer

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Re: FM Radio Reception while airborne
« Reply #2 on: July 11, 2018, 2014 UTC »
Cool to see mention of this.  I have been doing FM DXing from planes (airliners) since the late 80s.  Maybe during 15 flights.  The coolest was a British Airlines 747 to Loondon May 1996 - 100.7 North Bay Ontario hung in over 1.5 hours, at one time maybe 3 hours before landing I heard Icelandic FM stations for a brief time, then Irish FMs (Irish FMs have a lot of power (up to 300 kW ERP) compared to Icelandic Fms (2 to 15 kW max).

I also did this going to/from hawaii: returning to SFO, I started hearing SF Bay FM stations, especially the ones coming from Mt. Beacon above Sausilito - several were in well just via a Walkman and its HP cord "antenna" TWO HOURS before landing (I'd say maybe 800 miles over the Pacific.

In November 2013 I recorded CHINESE FM stations (SFO-PEK) 2 hours before landing - over Manchuria.  Corwded dial there too.

IN Sept. 1995 - RENO AIR allowed radios aboard, so I openly DXed via a Sangean ATS-808 both FM and AM!  I caught a cool recording of 1450 Portland right over the town, and noted the "cone of silence" as that station did a fade-out over PDX then came back in as we flew ever more to the north-north-west.  Once 103.7 Bellingham begau to fade out over the north-west section of Vancouver Island, a Canadian Weather station dominated for a spell.  Also caught some AK Panhandle stations on FM  1.5 hours before landing at Anchorage. 

I used to frequently, in the 80s, use a Fisher AM/FM micro-cassette unit to record in stereo the FM airplane DX. to keep the antenna hidden away from prying air-cew eyes, I employed a 1/4 wave long insulated wire with a alligator-clip to the telescoping antenna, so I could drape the wire discreetly along the window-seat arm-rest.  Position is cirtical.  The signals come in via the windows only.

Just to be safe, I often kept the FM dial below 97 MHn so its oscillator would not radiate in the VOR band above 108 MHz.

These days, a portable COBY MP3 player/FM radio is a very discrete way to do this.  I have a twim-lead (unshielded) patch-cord with a series X2) 300 uF chokes at the dig. recorder side (a Zoom H2) to keep the RFI from the dog. recorded out of the Coby Player's FM radio.  This works fab.  and is not very "obvious" either.

These days, the airliners employ GPS, so I hardly worry about oscillator emissions, but keep it all discrete anyway.  Cool way to go about it.

Back in June 1979 I made AM station recordings via a pocket AM radio up against the window flying from SFO to Mexico City - THAT was awesome...

MB