Do you still listen to FM when on an airplane?

[KeithE4]

Is it really a violation of federal law or a violation of the airline law?

14 CFR 125.204 states:

Sec. 125.204 Portable electronic devices.

(a) Except as provided in paragraph (b) of this section, no person
may operate, nor may any operator or pilot in command of an aircraft
allow the operation of, any portable electronic device on any U.S.-
registered civil aircraft operating under this part.

(b) Paragraph (a) of this section does not apply to--
(1) Portable voice recorders;
(2) Hearing aids;
(3) Heart pacemakers;
(4) Electric shavers; or
(5) Any other portable electronic device that the Part 125
certificate holder has determined will not cause interference with the
navigation or communication system of the aircraft on which it is to be
used.

(c) The determination required by paragraph (b)(5) of this section
shall be made by that Part 125 certificate holder operating the
particular device to be used.

Link: Code of Federal Regulations, Part 14, Section 125.204

The little local oscillator signal that every FM receiver emits would go 10 feet before being too weak to hear. The signals from the ATC tower would be around 30 dBu at worst, and the antenna is in the cockpit or outside the plane, so the local oscillator wouldn't do any damage. Cell phones have several watts of power and can cause more interference, and I'm sure someone forgets to turn off their cell phone on any given flight, and we haven't heard any reports of any problems because of that.

The problem is that the LO of an FM receiver with a 10.7 MHz IF is between 98.7 and 118.7 MHz (high-side LO) or 77.3 to 97.3 MHz (low-side LO). Some FM receivers with a low-side LO can tune below 88 MHz, which could put the LO below 76 MHz, which IIRC, includes an aircraft beacom band among other services. The frequencies 108-118 MHz (high-side LO) are aircraft navigation frequencies and are about as sacred as any frequency in the spectrum. Doesn't matter how strong or weak the LO signal is. The aircraft's receivers are sensitive enough to pick it up, depending on where you sit in the aircraft.

The rules are clear: Don't do it unless the pilot says it's OK (and in the case of commercial airlines, the chances of that are somewhere around zero)!

 

[tomservo]

I've done it once or twice but haven't flown lately and wouldn't attempt it anymore without permission from the cabin crew/pilot. The IF of the FM radio lays right down over the aircraft band as previously noted and dismiss any notions about that birdie not being strong enough - you're inside the cabin with the aircraft radio equipment. It doesn't get any closer than that.

That being said, I also heard several FMs from hundreds of miles out on a night flight over Texas. The static-y overlaid sound was unlike anything I'd ever heard before on a radio. Even dropping the receiver to mono, there was this odd-sounding crackle in the background... I guess that's the sound of 4-5 radio stations all hitting the receiver with relatively the same strength!

AM also worked okay, but instead of distant DX I only got what seemed to be directly below - ie., not much.

The most fun was hooking up the Bluetooth GPS unit to my PDA and watching the roads 30,000 feet below fly by on the screen. ;D

Next... What about bringing a portable TV on a plane? Better do it soon before the analog shutdown!

 

[nd2023]

It should theoretically sound like an intense e-skip opening...many stations fighting on each frequency with strong signals.

 

[fortaz107]

I can see the problem if you are Broadcasting something with a radio, but I don't understand how just picking up signals that are already in the air with a radio can cause any problems.

 

[radioguybroadcasting]

I can see the problem if you are Broadcasting something with a radio, but I don't understand how just picking up signals that are already in the air with a radio can cause any problems.

As someone said just a few posts above us:


The problem is that the LO of an FM receiver with a 10.7 MHz IF is between 98.7 and 118.7 MHz (high-side LO) or 77.3 to 97.3 MHz (low-side LO). Some FM receivers with a low-side LO can tune below 88 MHz, which could put the LO below 76 MHz, which IIRC, includes an aircraft beacom band among other services. The frequencies 108-118 MHz (high-side LO) are aircraft navigation frequencies and are about as sacred as any frequency in the spectrum. Doesn't matter how strong or weak the LO signal is. The aircraft's receivers are sensitive enough to pick it up, depending on where you sit in the aircraft.

LO=Local Osscilattor

 

[fortaz107]

I can see the problem if you are Broadcasting something with a radio, but I don't understand how just picking up signals that are already in the air with a radio can cause any problems.

As someone said just a few posts above us:


The problem is that the LO of an FM receiver with a 10.7 MHz IF is between 98.7 and 118.7 MHz (high-side LO) or 77.3 to 97.3 MHz (low-side LO). Some FM receivers with a low-side LO can tune below 88 MHz, which could put the LO below 76 MHz, which IIRC, includes an aircraft beacom band among other services. The frequencies 108-118 MHz (high-side LO) are aircraft navigation frequencies and are about as sacred as any frequency in the spectrum. Doesn't matter how strong or weak the LO signal is. The aircraft's receivers are sensitive enough to pick it up, depending on where you sit in the aircraft.

LO=Local Osscilattor

Thanks for clearing that up for me radioguy!~

 

[radioguybroadcasting]

I can see the problem if you are Broadcasting something with a radio, but I don't understand how just picking up signals that are already in the air with a radio can cause any problems.

As someone said just a few posts above us:


The problem is that the LO of an FM receiver with a 10.7 MHz IF is between 98.7 and 118.7 MHz (high-side LO) or 77.3 to 97.3 MHz (low-side LO). Some FM receivers with a low-side LO can tune below 88 MHz, which could put the LO below 76 MHz, which IIRC, includes an aircraft beacom band among other services. The frequencies 108-118 MHz (high-side LO) are aircraft navigation frequencies and are about as sacred as any frequency in the spectrum. Doesn't matter how strong or weak the LO signal is. The aircraft's receivers are sensitive enough to pick it up, depending on where you sit in the aircraft.

LO=Local Osscilattor

Thanks for clearing that up for me radioguy!~

No problem, glad to help!

 

[Timewarp]

I have DXed from high buildings and mountain tops. It can be exciting. But I would not want to
be a plane crash victim caused by my own foolishness,

 

[rbrucecarter5]

I have DXed from high buildings and mountain tops. It can be exciting. But I would not want to
be a plane crash victim caused by my own foolishness,

I was actually disappointed by Pike's Peak DX - 200 mile stuff, not much more. But it is only 8000 feet above the city of Colorado Springs. I had much more luck in the Rocky Mountains - the dial was jammed with multiple stations on each frequency. But - was that particular day a skip even? I'll have to try again!

 

[Channel Surf]

I always use my old 1988 digital Sony Walkman when I fly. I always request the window seat too. FM reception is phenomenal but it changes constantly, with in minutes. It is similar to the type of FM skip that you encounter during the summer. By the way...the Air Marshalls haven't come after me yet....

 

[KOOL Listener Lauren]

Have I not seen this topic, I wouldn't have never known that there's a federal law against listening to the radio on an airplane!

Two summers ago was the first time I've ever flown, and probably what I enjoyed more than the sight from the window, was hearing all kinds of stations. I spent the entire four hour flight going up and down the FM dial, one by one. Sometimes I could even pick up pilots talking to Air Traffic Control.

The flight attendant told me to have it off when taking off and landing, but perhaps they assumed I was just listening to a CD on my Walkman CD/Radio. Perhaps it also depends on the airlines, as I do know the airlines I chose are more laid back and lenient than others.

I suppose next time I will ask for permission, and where the best place would be to sit without risking any possible cases of interference or confusion. At least the pilots could be aware, so that when worst comes to worst, they would know what the problem is and tell us to turn off our radios over the intercom.

 

[dxer2_2000]

Hi

I was allowed by the pilot to DX in a private plane & he flew at higher than the usual 16,000FT (22,000FT just to improve the DX for me) ;D
I asked him was there any interference to his instruments & he said no. This is a small plane too (Kingair B-200). I was able to tune the entire FM band w/ no worries.

I find the fuselarge creates HUGE attentuation & I had NO reception until we got above 3000FT. Below that, the FM signals would simply fade out.

FMDX is like tropo with little or no fading. Reception was to around 500km. I used an AM/FM tuner running off its own batteries & used one of those t shaped ribbon antennas. I used a boombox to record the reception in stereo. Unfortuneatly, the poor old analogue tuner lacked the selectivity to seperate stations & was hard DXing without digital readout too.

dxer2_2000

 

[DXER24]

I went to Florida with my HS band for the band festival and as we were flying back I was sitting next to a freind of mine and was DXing and the flight attendent said I could do that but when we land I needed to turn it off

 

[KyDXIn]

I have DXed from high buildings and mountain tops. It can be exciting. But I would not want to
be a plane crash victim caused by my own foolishness,

Whats the last thing a DXer hears in a plane? The high pitched girlish scream as the plane crashes!




AAAAAAAAAAAAAAAAARRRRRRRRRRRRRRRRRRRRRRGGGGGGGGGGGGGGGGGGGGGGGGGHHHHHHHHHHHHHHHHHHHHHH!!!!!!!!!!!!!!!!!!!

 

[tomservo]

Anyone — name a plane crash attributed to someone playing with an FM radio. ;D

 

[nd2023]

Has there ever been a plane crash due to pirate stations?
At Newark, NJ, there are over 20 pirate stations on the air for years, yet we haven't heard about any plane crashes because of them. The pirate transmitters would probably emit spurs over 108 mhz much stronger than local oscillators. There's even some pirates less than a mile away from the airport.

 

[softmachine]

Is it really a violation of federal law or a violation of the airline law? The little local oscillator signal that every FM receiver emits would go 10 feet before being too weak to hear. The signals from the ATC tower would be around 30 dBu at worst, and the antenna is in the cockpit or outside the plane, so the local oscillator wouldn't do any damage. Cell phones have several watts of power and can cause more interference, and I'm sure someone forgets to turn off their cell phone on any given flight, and we haven't heard any reports of any problems because of that.

I thought the old bag phones had several watts of power-not newer handsets.

 

[shadough]

I havent done it since 9/11. But I did do it before. I have a small 'aircheck' of XL-106.7 Orlando from the plane traveling over north florida and Georgia on my way back to DC. I think it was '95 actually. I'll try an post it up here when I get the chance. ONe thing I remember was being able to listen to Q94 in Richmond (VA) all the way until almost the planes landing, up-to the final approach at least, we were landing @Dulles.

 

[tomservo]

I thought the old bag phones had several watts of power-not newer handsets.

Those and car-mounted phones had (I think) 3 watts max on the old AMPS system. I'm pretty sure that people are still using them in areas where analog signals have yet to be turned off. I used a portable in analog mode many times in Alabama because there digital signals just didn't work out in the boonies, and this was in 2005.

AFAIK most handsets are in the range of 600 mW max output. Maybe CDMA sets are higher, I dunno nuttin' bout them things.

 

[FroDX]

Back in 1992 on a flight from Phoenix to Fresno, I got KUPD all the way up to when we were over Death Valley. That is when it started mixing with country and a soft rock station that I could not ID. I also picked up KBAY-100.3, 104.1 and 103.3 from Modesto and mixture of Las Vegas, Fresno and LA stations over Death Valley area. As soon as we passed over the Sierra Nevada's San Joaquin Valley stations were mixing with Bay Area stations. I also got KTYD-FM 99.9 Santa Barbara, KWNZ-FM 97.3 Reno and 91X San Diego pretty good over DV. I did ask the flight crew if it was ok to use the FM radio and they said they had no problem with it. I also noticed that some stations from the same city could not be picked up when others could. I guess this might have to do with the type of antenna set up they have, beam tilt, directional, etc...