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Mystery signal from a helicopter

windytan.com

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Re: Mystery signal from a helicopter

#71

Post by dsuth »

wglb wrote: post #57
nl wrote: post #36

I love this: Several people in the restaurant were waiting for orders with their similar devices, which suggested to me this could be a pager system of some sort. Turning the receiver over, we see stickers with interesting information, including a UHF carrier frequency. For this kind of situations I often carry my RTL2832U-based television receiver dongle with me (the so-called rtl-sdr). I knew I was forgetting somet…

For this kind of situations I often carry my RTL2832U-based television receiver dongle with me But of course.

As you would, really.

Re: Mystery signal from a helicopter

#73

Post by _b8r0 »

tezmc wrote: post #16
jgrahamc wrote: post #13

I love Oona Räisänen's blog. She's my hero. She combines a love of figuring stuff out with lots of fun hacks. And when I read her blog it makes me happy to see someone with that joy of uncovering mysteries.

You've probably already seen it, but in case you haven't: her talk at 30C3 was excellent and is worth a watch. https://www.youtube.com/watch?v=R-2k6TMPMRo

The talk was first given at 44CON in September in 2013 (but only available on the DVD, not posted on the youtube channel).

Funnily enough, this isn't the first time Oona's RDS adventures have been on HN[1]. Indeed, there's a comment from a while back on here[2] from the time I was trying to convince her to submit to 44CON. The thing that really surprises a lot of people is that Oona does this sort of thing in her spare time.

[1] - https://news.ycombinator.com/item?id=5656677

[2] - https://news.ycombinator.com/item?id=5657930

Re: Mystery signal from a helicopter

#74

Post by sharpneli »

sown wrote: post #40
nl wrote: post #36

I love this: Several people in the restaurant were waiting for orders with their similar devices, which suggested to me this could be a pager system of some sort. Turning the receiver over, we see stickers with interesting information, including a UHF carrier frequency. For this kind of situations I often carry my RTL2832U-based television receiver dongle with me (the so-called rtl-sdr). I knew I was forgetting somet…

http://www.oz9aec.net/index.php/gnu-radio/gnu-radio-blog/464... I think this is what she was talking about? Note to self: buy one! :D

http://www.amazon.com/NooElec-RTL-SDR-RTL2832U-Software-Pack...

It's so cheap it's practically free (I mean come on, 3.2MHz BW for that price?). The included antenna is horrible but it suffices for small things like finding out something about the restaurant buzzers.

Oona is doing an extremely important service for Ham radio communities etc. She is bringing the knowledge of all of this to a wider audience on the internet.

Re: Mystery signal from a helicopter

#75

Post by DanBC »

TeMPOraL wrote: post #70
nl wrote: post #36

I love this: Several people in the restaurant were waiting for orders with their similar devices, which suggested to me this could be a pager system of some sort. Turning the receiver over, we see stickers with interesting information, including a UHF carrier frequency. For this kind of situations I often carry my RTL2832U-based television receiver dongle with me (the so-called rtl-sdr). I knew I was forgetting somet…

I've seen similar devices in a pizza joint. Does anyone know why they are so big and ugly?

So people don't steal them; so people have to hold them or put them on a table and don't miss when they buzz.

Re: Mystery signal from a helicopter

#76

Post by coldtea »

DonGateley wrote: post #72
vhost- wrote: post #42

The thing I love most about her work is it's witty, but to the point and I can always understand it. I'm not a big fan of the tl;dr movement, but I also don't like dauntingly long blog posts. Nails it every time. Hats off!

What is the tl;dr movement?

He means people complaining that a post is too long and so they won't read it.

Re: Mystery signal from a helicopter

#79

Post by unwind »

graupel wrote: post #54

We operate news helicopters at TV stations around the US and they all use a similar system. Basically the right channel of audio is typically the microphone from the pilot or reporter and the left channel is the audio feed transmitting what is basically modem data back with the GPS coordinates of the helicopter and some other data. This data is used at the antenna site to track the helicopter and point the antenna in…

I'm not a native speaker, but still have a pet peeve for that one. It's "line-of-sight" (http://en.wikipedia.org/wiki/Line-of-sight).

Light travels in a straight line over (human-scale) long distances, so you need a straight line free from obstruction to see between two points. I'm sure you know this and just made a typo, of course.

Thanks for the additional information about this interesting solution.

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