For example, Richard Nixon was decidedly “G” rated (see right). Given that most hams in the 1950s and 1960s were men and the times were different, a lot of them were more or less “R” rated. Ham radio operators who use teletypes (RTTY, in ham parlance) often had vast collections of punched tape that held artwork. Calendars with some artwork were also popular (see left, and find out about the FORTRAN that created it, if you like). One of the earliest forms of computer-generated graphics used text characters to draw on printers.Įarly computer rooms were likely to have a Snoopy character on green and white fan-fold paper. However, it hasn’t always been like this. Some video games today exceed what would have passed for stunning cinema animation only a few years ago. Posted in Misc Hacks, Radio Hacks Tagged amateur radio, fft, ham, hash, modulation, PACTOR, PSK, rtty, Shazam, SigIDĬomputer graphics have come a long way.

There are some waterfall examples in ’s excellent article on RF modulation that could get you started. We really like the idea here, and wonder if it can be expanded upon to visually decode signals based on their waterfall signatures using TensorFlow.

Whether it be the weird, dissonant wail of PSK-31 or the angry buzzing of PACTOR, the goings-on across the bands no longer have to remain a mystery. With a five to ten second sample of a signal, captured either live over a microphone or from a recording, he is able to identify the signal automatically. The database contains hashes for an FFT of each sample, which can be easily searched. used a homebrew version of the app to search a SQL-lite database of audio fingerprints populated not with a playlist of popular music, but with samples from every known signal type in the Signal Identification Wiki. Shazam is a popular smartphone app that listens to a few seconds of a song, creates an audio fingerprint of it, and searches a massive database of songs for a match. has made progress toward automatically classifying unknown signals by modifying a Shazam-like app. Now, the ham bands are full of exotic signals encoding all manner of digital signals, each one with a unique sound and unique demodulation needs. Spinning the dial up and down the bands, one heard familiar sounds – the staccato of Morse, the of sideband voice transmissions, and the occasional flute-like warble of radioteletype signals. Time was once that the amateur radio bands were an aurally predictable place.

Amateur radio rtty