Re: [Discuss-gnuradio] VGA-based DVB-T modulator

[Johnathan Corgan]

Seth David Schoen wrote:

> Someone proposed this a while ago, but Fabrice Bellard (who is also
> responsible for cool stuff like the tcc compiler, which lets you use
> C as a scripting language and lets the Linux kernel compile itself
> at boot time) has used a VGA card's DAC as an RF modulator to produce
> a valid DVB-T signal.

I sure wish I could remember where to find it, but I've seen 
demonstrated a program that would generate valid AM waveforms by 
displaying certain pictures on a video screen.  You'd enter a target 
frequency (I think in the HF range) and choose a MIDI sound file, and it 
would "modulate" the CRT display to emit RFI at that frequency with the 
tones riding as AM modulation.  Very spooky.  It was a demonstration of 
the security hazards associated with CRT displays (TEMPEST stuff) in a 
very palpable way.

-Johnathan