Oona Räsänen

BTW, every post from this blog is amazing. See the two recent ones:

http://www.windytan.com/2017/09/descrambling-split-band-voice-inversion.html "Voice inversion is a primitive method of rendering speech unintelligible to prevent eavesdropping of radio or telephone calls."

http://www.windytan.com/2017/07/virtual-music-box.html "A little music project I was writing required a melody be played on a music box. However, the paper-programmable music box I had (pictured) could only play notes on the C major scale. I couldn't easily find a realistic-sounding synthesizer version. [...] Perhaps, if I digitized the sound myself, I could build a flexible virtual instrument to generate just the perfect sample for the piece!"

My favorite is "Mystery signal from a helicopter" http://www.windytan.com/2014/02/mystery-signal-from-helicopter.html

I have a couple of NESDR Smart dongles from NooElec [1], that have worked very well for me. I run them on a Raspberry Pi 3 and pipe audio output to my desktop or laptop with PulseAudio.

Aside from SDR# on Windows and gqrx on Linux, there's also GNU Radio [2] and a variety of lightweight applications that can run on, let's say, a Raspberry Pi Zero [3]. Oona Räisänen has a fascinating blog that touches on digital signal processing as well, applicable to SDRs as well.

Me? No ham license, but that may come someday.

[1] https://www.nooelec.com/store/

[2] https://www.gnuradio.org/

[3] https://osmocom.org/projects/rtl-sdr/wiki/Rtl-sdr

[4] https://www.windytan.com/

The author of this, Oona Räisänen, is one of my standard examples of someone who is genuinely a hacker in the proper (by which I mean, the Stephen Levy "Hackers" definition; if you want to use the prior MIT prankster meaning, I won't stop you) sense.

This post of Oona's - http://www.windytan.com/2014/02/mystery-signal-from-helicopter.html - in which she extracts, from the audio of footage from a news helicopter, the location of that helicopter, is an excellent example.

Given that someone here recently defined "hacker" to me as "person who can write code", the word is in serious danger of being so devalued as to be useless.

Did you know each manufacturer had a unique sound for their v90 handshake? This one sounds like a Lucent WinModem. (Based on listening to the sounds here[1]. Yay for RealAudio!) The USR/3Com modems were two "bongs" (four if the higher speed failed). But I was always fond of the Rockwell sweep[2].

Of course, required reading is HN favorite Oona Räisänen's excellent analysis of a modem handshake.

[1] http://modemsite.com/56k/trouble3.asp

[2] https://www.youtube.com/watch?v=vvr9AMWEU-c

[3] http://www.windytan.com/2012/11/the-sound-of-dialup-pictured.html

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 something.

http://www.windytan.com/2013/09/the-burger-pager.html

A few of mine:

- https://www.windytan.com/ (windytan: signal processing)

- https://www.righto.com/ (Ken Sheriff: IC reverse engineering, vintage computing, misc)

- https://jvns.ca/ (Julie Evans: software development, particularly networking)

And even though it's not a written blog, a special mention goes to Ben Eater's website, which links to his fantastic YouTube series on building an 8-bit CPU from logic chips, and on building a 6502 computer.

- https://eater.net/