More SSB / GnuRadio Learning

I learned how to do the SSB demodulation, using the article mentioned in the previous post, and the tutorial grc_tutorial4. Forgive my fumbling attempts at a screen/audio capture, but here is recorded proof that it demodulated the recorded signal:

I first followed the tutorial to the letter, but that didn’t work, so I retranslated the ideas into some other blocks. Then I found I had to adjust the frequency some from what was described in the tutorial.

Here are just the blocks:

Weaver SSB Tutorial

I wanted to add a few search engine points to this nifty tutorial on modulating/demodulating Single Side Band:

Weaver SSB Modulation/Demodulation – A Tutorial

It only covers real signals, rather than complex signals, but has been helpful to me nonetheless in understanding the concept. It is critical however, when you get to the math formulas, to try to visualize in your mind the different wave components being represented.

I’ve made it part way through, up through modulation. One great thing about Gnu Radio Companion is it allows you to go through these kind of tutorials without a radio hooked up. Here are the blocks, with a final “RF” stage going up to an amazing 3khz (to keep it in the FFT graph), with a ω₀ at 1500 hz:

Hopefully there are no embarrassing misunderstanding represented there, but when I ran it, I seemed to be getting side bands centered around 3khz.