Radio stations, in a flight

[swhyde1980]

I know we found out some years ago, that listening to a radio on an airplane is unsafe and could interfere with communications on a jet. But, before we found this out, is there anyone on here that listened to radio while on a flight to somwhere?? I remember some Seattle stations were coming in, while over Eugene, OR. Lots of interference of course, with frequencies obviously overlapping with each other. But I remember almost every single frequency, 30,000 feet in the air, had something on it. Of course now with new FAA restrictions, we can't do that anymore. But did any of you do this back then?? Would like some experiences or thoughts, if any of you did the same thing.

 

[LITTLEBOYBLUE]

I did it quite a while AFTER it was illegal. I didn't realize radio receivers were verboten and had a "walkman" that I would tune in stations while flying to midwest. Was cool because you could hear all the small market things along the way. Somehow, despite my ignorance, the plane stayed on course and landed just fine....

 

[mimo]

It's still legal in Canada, and I do it here. We can't do it during take offs and landings, but we can during the main part of the flight.

 

[Bongwater]

I too once flew to L.A. with a Sony Walkman....though I made the STUPID move of putting the receiver up by the window. Within a half hour at 20,000 feet, a stewardess busted me. But in that narrow time frame, I could hear KNDD rock solid right over Portland....with some spillage from KUMA-FM (also on 107.7) in Pendleton......

I think they make the rules against radios mainly for the benefit of their in-flight audio/video content providers and not so such for "aircraft safety". There's a LOT of commercial radio towers around airports blasting out a lot more power than my little 2 AA battery powered Walkman ever could. Also I believe I read once that aircraft radios for commercial jets are required to reject harmonic interference.....

 

[LITTLEBOYBLUE]

I think they make the rules against radios mainly for the benefit of their in-flight audio/video content providers and not so such for "aircraft safety". There's a LOT of commercial radio towers around airports blasting out a lot more power than my little 2 AA battery powered Walkman ever could.

Yeah, like KNX/Los Angeles. Uh-oh...it's down. OOpsie..check that. Back up again. Never mind. But the little private PLANE didn't do so well in that one! Seems in that case the "gotcha" wasn't the radio transmission but jamming a huge tower in the landing PATH of the airport!!

 

[boiseengineer]

From Seattle to Spokane had quite a few Seattle station in until a couple minutes of landing.
It's not harmonics that cause the "problem". It's the IF oscilator that puts out a signal 10.7 MHz above what you're tuned into. Just keep the radio below 97.3 and that pesky IF signal will stay below 108 and out of the aircraft band.

 

[DanStrassberg]

Yeah, like KNX/Los Angeles. Uh-oh...it's down. OOpsie..check that. Back up again. Never mind.

Don't you mean KFI?

 

[Bongwater]

FROM THE CREATORS OF "SNAKES ON A PLANE" COMES "RADIOS ON A PLANE"!!......

.....THE ULTIMATE AVIATION HORROR!!

YOU'LL SEE! BIG BOEING JETS SUDDENLY FALL FROM THE SKY IN FASHIONABLE SUBURBAN NEIGHBORHOODS BECAUSE SOMEBODY TURNED ON THEIR WALKMAN!!.....

YOU'LL HEAR! THE SCREAMS OF PILOTS TRYING TO CONTACT TRAFFIC CONTROL OVER THE BOOT SCOOTIN' COUNTRY ON KMOK OVER CHEHALIS!!......

YOU'LL GASP! AT THE BIG BUDGETS FOR CRAPPY SELECTIONS OF IN-FLIGHT AUDIO/VIDEO PROGRAMMERS!!.....

YOU'LL SMELL! A RAT!!.......

YOU'LL FEEL! LIKE SCREAMING!!.....

DON'T MISS "RADIOS ON A PLANE" COMING THIS CHRISTMAS TO YOUR IN-FLIGHT VIDEO PLAYER........

 

[LITTLEBOYBLUE]

Yeah, like KNX/Los Angeles. Uh-oh...it's down. OOpsie..check that. Back up again. Never mind.

Don't you mean KFI?

Yes, thanks. KNX didn't feel right when I was typing...but too lazy to go back and look it up! Thanks for keeping me honest!!

 

[crainbebo]

Man, would I have a radio up in the sky. I think, over in Portland, you would get every Seattle station, every Tri-Cities station, every Yakima channel, every Eugene station, etc.

-crainbebo

 

[swhyde1980]

Well, if I remember correctly, just past Portland (when I did this in 1995).... KMGE on 94.5 (Magic 94.5, Eugene), KNRK on 94.7, KUOW on 94.9, KITI on 95.1 (Live 95, Centralia), KXLE on 95.3, KXL on 95.5 (at the time...Music Radio 95, Portland), KJR on 95.7, and KXXO and KZEL fighting over 96.1. Pretty much, every frequency had something on it.

I believe, FM stations create a "funnell" pattern up in the air. I'd imagine if you were like 15-30 miles up in the air, FM would be unlistenable, with so many stations overlapping each other.

LOL....would be interesting if anyone took a radio, to the top of Mt. Rainier...

 

[multiplex]

I did it on a few flights. Over southern Oregon, I got stations from Stockton CA to Portland, with a huge mess on channel 6 (87.75.)
I mostly stayed below 97mHz to avoid generating an IF in the aircraft band.
I also listened on a cross-country flight, with a full dial in even the most desolate places.
These days folks are allowed to use laptops which put noise everywhere, so the radio ban is rather silly, since enhanced conditions probably overshadow anything radios produce. Canada's got it right.

 

[crainbebo]

Do you have any loggings of your stations over S. Oregon? If you do, post it!

I did it on a few flights. Over southern Oregon, I got stations from Stockton CA to Portland, with a huge mess on channel 6 (87.75.)
I mostly stayed below 97mHz to avoid generating an IF in the aircraft band.
I also listened on a cross-country flight, with a full dial in even the most desolate places.
These days folks are allowed to use laptops which put noise everywhere, so the radio ban is rather silly, since enhanced conditions probably overshadow anything radios produce. Canada's got it right.

-crainbebo

 

[swhyde1980]

I never tried a portable TV in the air, but I imagine the interference from the jets on a plane would have prevented acceptable reception.  And now that we are in the digital TV age, I don't think 8VSB modulation does well 30,000 feet in a jet too well either.

 

[DanStrassberg]

I believe, FM stations create a "funnell" pattern up in the air. I'd imagine if you were like 15-30 miles up in the air, FM would be unlistenable, with so many stations overlapping each other.

The vertical pattern of an FM signal with a high-gain transmitting antenna is kind of a squished donut (with a zero-diameter donut hole). If the station employs electrical beam tilt, the squished donut becomes something closer to a very flat, upside-down wine glass (without the stem but with rather thick glass walls).

VHF signals are limited to the horizon. The higher you go, the more the horizon expands. When you are seven miles above the earth's surface, the horizon is located several hundred miles along the earth's surface from the ground position immediately below your location. The reason for the great FM DX when you are flying in an airplane is that signals that are no longer accessible to terrestrial receivers because of the earth's curvature (that is, signals from beyond the horizon at the transmitting antenna) are accessible to your high-altitude receiving antenna in the airplane.

 

[louisNatl]

From what I've read around the 'net, portable walkman-like devices that are dedicated as AM/FM radios are not allowed in flight but radio-enabled MP3 players are. The logic is that the MP3 players do not produce as much interference. Otherwise, Microsoft's Zune MP3 player would not be allowed in-flight whereas the iPod is. I'll see what happens when my Zune accompanies me on the next flight.

 

[crainbebo]

Yes, you shouldn't put your radio above 98 mHz, or the I.F's will come!

-crainbebo