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Ultimate DX/High Altitude Reception Experiment?

B

Buckeyes2001

I think I found the ultimate way to experiment with high altitude reception. There are videos taken from weather balloons that go as high as 106,000 feet above ground and return to earth via a parachute. Imagine also attaching a small radio such as the Tecsun PL-390 to the balloon, have the camera facing the radio and the radio on scan mode or somehow rigged to step through each frequency for a few seconds at a time as the balloon ascends at about 15 feet/second. Here is one such video of footage taken from a high-altitude weather balloon. Imagine what the FM and AM reception would be like at over 100,000 feet!

http://www.youtube.com/watch?v=1h0ptpimm04&fmt=18
 
Buckeyes2001 said:
I think I found the ultimate way to experiment with high altitude reception. There are videos taken from weather balloons that go as high as 106,000 feet above ground and return to earth via a parachute. Imagine also attaching a small radio such as the Tecsun PL-390 to the balloon, have the camera facing the radio and the radio on scan mode or somehow rigged to step through each frequency for a few seconds at a time as the balloon ascends at about 15 feet/second. Here is one such video of footage taken from a high-altitude weather balloon. Imagine what the FM and AM reception would be like at over 100,000 feet!

http://www.youtube.com/watch?v=1h0ptpimm04&fmt=18
Click to expand...

The biggest problem would be that there is no air to speak of at altitude to support sound, so you would need a direct connection to the camera's auxiliary audio input. I think a small PIC board could be programmed to step through the frequencies, just a little radio hacking and you would be set.
 
K6JHU said:
FM is aimed at the horizon. The balloon is mostly straight up. May not be all that good for reception :)
Click to expand...
Maybe go for AM since that can bounce across the ionosphere.
 
K6JHU said:
FM is aimed at the horizon. The balloon is mostly straight up. May not be all that good for reception :)
Click to expand...

Note that field intensities arriving at such elevations from distant VHF/UHF stations can be much greater than those from stations directly beneath such receiving locations -- due to the elevation patterns/ERPs of the various transmit antennas toward the balloon receive site.

The directional characteristics of the receive antenna on the balloon also are important to the end result.
 
At 100,000 feet, all you'd get are dozens of stations on a freq [similar to 1450 on a good night.] What I'd love to see is a weather balloon 35,000 feet above Seattle, with a Grundig G8 or Tecsun unit strapped on it. Imagine the reception! Boise FMs anyone?

-crainbebo
 
Distance to the horizon (assuming nothnig in the way) at 35,000 feet is about 230 miles. Still a stretch to Boise.

BTW, at 100,000 ft the distance is about 388 miles.

But this does not count the height of the transmitter end. Boise transmitter at 7300' is 104 miles to the horizon. So best case (again assuming nothing in the way) is 334 miles. Seattle-Boise is about 400 miles. We are close, really close.
 
On my (once) frequent flights to Europe, I'd have fun pulling in local FMs, as we flew over the UK and 'the Continent', so I was pretty stoked about what I could snag on my Hong Kong trip in '05. The flight path took us over vast chunks of North America, brushing Alaska, Russia, into Japan, on the edge of Taiwan and mainland China...alas, listening to radio, while in flight, was (is) no longer permitted...:(

~BG
 
It may no longer be permitted, but I've managed to sneak a listen on some very uncrowded flights post 9/11 and have heard all kinds of interesting things. I definitely didn't hear what was directly beneath me, but things that were 150-250 miles off, which was interesting. Weirdest part was how quickly the stations would blend from one to another, but it was not a mish-mash like on AM due to the capture effect. In fact, in transitory areas it was just static, but the receiver's signal strength meter stayed pretty well pegged the whole time.

AM was more disappointing but there were a few stations coming and going, despite being inside a big metal tube. It's been a while so my memory's sketchy, but I think it was mostly high band / X-band stuff.
 
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