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Serious FMDX at high altitude - 16,500FT

D

dxer2_2000

Hi all

I was lucky enough to have an opportunity to FMDX from a high altitude aircraft at 16,500 FT for 40mins. It was in a private company plane - a twin prop Beechcraft 250.

The pilot allowed me to do FMDX (max was very easy going & in fact, invited me on the trip!!!).

Equipment:

TEAC T-515 AM/FM tuner modified to run off 6 AA batteries (DC power)
indoor T shaped ribbon antenna tacked near the windows using blu-tack
Sanyo boombox to record the audio/reception.

Results? - reception is like a huge tropo opening with FM signals being very stable - no fading. Tuning across the FM band produced wall to wall signals with a range of about 400km.

I used an FM tuner as these perform much better than most portable radios. It certainly was a rare opportunity! I got some nice recordings in STEREO.

Flying over the Snowy Mountains in southern NSW, locations that were STRONG were Albury NSW, Wagga NSW, Young NSW, Shepparton VIC, Traralgon VIC & Canberra ACT.
Best catch was Orange NSW on 105.9. Suprisingly, Melbourne & Mildura VIC was absent on this frequency.


Cheers
dxer2_2000 - Australia
 
> Hi all
>
> I was lucky enough to have an opportunity to FMDX from a
> high altitude aircraft at 16,500 FT for 40mins. It was in a
> private company plane - a twin prop Beechcraft 250.
>
> The pilot allowed me to do FMDX (max was very easy going &
> in fact, invited me on the trip!!!).
>
> Equipment:
>
> TEAC T-515 AM/FM tuner modified to run off 6 AA batteries
> (DC power)
> indoor T shaped ribbon antenna tacked near the windows using
> blu-tack
> Sanyo boombox to record the audio/reception.
>
> Results? - reception is like a huge tropo opening with FM
> signals being very stable - no fading. Tuning across the FM
> band produced wall to wall signals with a range of about
> 400km.
>
> I used an FM tuner as these perform much better than most
> portable radios. It certainly was a rare opportunity! I got
> some nice recordings in STEREO.
>
> Flying over the Snowy Mountains in southern NSW, locations
> that were STRONG were Albury NSW, Wagga NSW, Young NSW,
> Shepparton VIC, Traralgon VIC & Canberra ACT.
> Best catch was Orange NSW on 105.9. Suprisingly, Melbourne &
> Mildura VIC was absent on this frequency.
>
>
> Cheers
> dxer2_2000 - Australia

Plane FMDXing is my favorite thing to do...

It is *technically* illegal in the states, though with equipment getting better, I have not heard any stewardesses say that listening is wrong for the last five or so years.

PS: Try FMDXing on a commercial jet at 32,000 feet! I was picking up a station from Nashville, TN while we were over the Atlantic Ocean!

Radio-X
 
> Plane FMDXing is my favorite thing to do...
> It is *technically* illegal in the states

Quick question on that topic... does the prohibition arise from some sort of über-caution about radiated additive interference from the signal and the LO (e.g., 103.9 + 10.7 = 114.6, which sits in the navigation portion of the VHF aeroband)? If so, just make sure to purchase a seat at least 10 or 12 rows back from the cockpit, and you should be able to avoid detection. (Yes, I actually experimented with the so-called "transmission" range of additive LO products... when I was 15, I did it to confuse the hell out of my mom as she tried to listen to her favorite lite-AC station in the car. :-D)
 
> > Plane FMDXing is my favorite thing to do...
> > It is *technically* illegal in the states
>
> Quick question on that topic... does the prohibition arise
> from some sort of über-caution about radiated additive
> interference from the signal and the LO (e.g., 103.9 + 10.7
> = 114.6, which sits in the navigation portion of the VHF
> aeroband)? If so, just make sure to purchase a seat at
> least 10 or 12 rows back from the cockpit, and you should be
> able to avoid detection. (Yes, I actually experimented with
> the so-called "transmission" range of additive LO
> products... when I was 15, I did it to confuse the hell out
> of my mom as she tried to listen to her favorite lite-AC
> station in the car. :-D)

That is supposedly the basis for the rule, and it makes perfect sense. I've seen cheapo radios bearing the FCC type-acceptance label throw a dead carrier for 80 feet, capable of covering commercial FM stations.

On a side note, I was recently on an international flight where ETon radios were being sold through the onboard duty-free shopping. I estimate that over a a dozen people could be seen playing around with their newly-purchased FM radios for the remainder of the flight. I can't say I was crazy about the idea, but even with all those oscillators dancing around, nobody came through the cabin looking for radio listeners as I had seen done on one flight to Mexico back in 1983.
 
AM DX on a beach... (was Re: Serious FMDX at high altitude - 16,500FT)

I've tried a couple times to do a little FM DX in a plane, but all I get is serious static on my Panasonic (Shockwave), or seriously attenuated signals. :(

Now...

I'd like to see someone...

take a large loop antenna (like what Bruce Carter builds) and a decent portable radio...
go to the beach (preferably away from a large city) AT AROUND NOON (this is to minimize skywave reception/interference, as relying too heavily on skywave (i.e. at night) would be cheating :p)
take your radio and antenna out INTO the water, say, knee-deep or waist deep or something. maybe you could even drop your antenna's ground INTO the water.
see how many / what stations you can DX, and how far you can get them from.
to challenge yourself you probably COULD take a radio with decent selectivity and an antenna with good directional nulls, and attempt to DX distant stations that are co- or adjacent-channel with locals.
 
Re: AM DX on a beach... (was Re: Serious FMDX at high altitude - 16,500FT)

> Now...
>
> I'd like to see someone...
>
> take a large loop antenna (like what Bruce Carter builds)
> and a decent portable radio...
> go to the beach (preferably away from a large city) AT
> AROUND NOON (this is to minimize skywave
> reception/interference, as relying too heavily on skywave
> (i.e. at night) would be cheating :p)
> take your radio and antenna out INTO the water, say,
> knee-deep or waist deep or something. maybe you could even
> drop your antenna's ground INTO the water.
> see how many / what stations you can DX, and how far you can
> get them from.
> to challenge yourself you probably COULD take a radio with
> decent selectivity and an antenna with good directional
> nulls, and attempt to DX distant stations that are co- or
> adjacent-channel with locals.
>

How about a longwire on the end of a fishing pole. Go deep-sea "fishing". While everybody is fishing, you're DXing.

I'm feeling the need for a vacation at the beach coming on.......
 
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