https://stream.echo6.co/videos/watch/2ff0f848-4646-42ae-93d6-dbed35b3bc59 How to setup DragonOS LTS, SigDigger, and the HackRF One to demodulate and view a drone's 5 GHz analog FPV in realtime. You'll need a 5 GHz capable antenna attached to the HackRF One and either a drone with analog FPV or a standalone analog camera. Shared background and technical info: https://sourceforge.net/projects/dragonos-lts/ https://github.com/BatchDrake/SigDigger Have in mind that as a general rule, the older an analog modulation is, the easier is to get basic results. This is due to the curse of backward compatibility: TV receivers were rather dumb back in the day, basically fast fax machines glued to an off-band FM radio receiver. The receiver circuits were also slow, and the signal had lots of invisible blank spaces in the borders so that the cheapest TVs could switch to the next line in time. The invention of Teletext leveraged those blanks in order to carry digital information and color information was embedded as an additional narrowband signal in the gaps in the spectrum. Something similar happens with FM stations: initially all of them broadcasted monaural sound, and stereo / RDS was added years later as ultrasonic carriers in the baseband signal that wouldn't be reproduced by older monaural receivers. So with this in mind I wanted to see if there was a way we could view the analog video of a drone using something like the HackRF One. This brought me to SigDigger. Now while the symbol view within SigDigger is technically not made for the purposes of viewing drone feeds, but to display symbols and symbols patterns. Due to this behavior we can incidentally view the contents of analog TV and weather faxes with lots of manual adjustment. The overall procedure within SigDigger is: Adjust the filterbox to the fit the signal completely, Open the FSK inspector, Set 8 bits per tone in the demodulator controls, Leave the Clock Recovery to Manual and click start. You should see the histogram of the signal having a particular hat-like shape (or elephant-eaten-by-snake-shape). Drag the left-most bulge to the right-most bulge in the histogram., Press "Fit to window" to disable it. The width spinbox should be enabled now., Press "Record". You should see a bunch of slanted lines., Reduce the width progressively (with the arrow keys for instance) until you recognize something., Adjusting the contrast is all about adjusting the histogram limits. Play a bit with it dragging the limits (right mouse button resets it) until you are happy with the result., Links discussing NTSC and how it works: https://batchdrake.github.io/ntsc-i/ https://batchdrake.github.io/ntsc-ii/ https://batchdrake.github.io/ntsc-iii/ https://batchdrake.github.io/ntsc-iv/ Sun, 03 May 2026 23:23:37 GMT https://validator.w3.org/feed/docs/rss2.html PeerTube - https://stream.echo6.co https://stream.echo6.co/client/assets/images/icons/icon-512x512.png https://stream.echo6.co/videos/watch/2ff0f848-4646-42ae-93d6-dbed35b3bc59 All rights reserved, unless otherwise specified in the terms specified at https://stream.echo6.co/about and potential licenses granted by each content's rightholder.