This post was supposed to be short, just a quick update to say “I made a better PicoFox”. It was supposed to be a marketing piece driving sales, expressing gratitude to the community for great feedback, etc, etc, etc. What foolish thoughts I had!
Instead this post is a 1,691 word discussion of dumb decisions and the frustrations of engineering tradeoffs. Also, I made a better PicoFox.
Have you ever had an idea so spectacularly dumb you had to make it happen?
After seeing several SI5351 based transmitters for HF I had the idea that maybe this chip could be pushed to do frequency modulation on VHF bands. It does glitchless frequency changes, it can generate VHF clocks, it even claims a 0 PPM error. We all know that last part is nonsense but the error is so low that we can pretend that it’s zero and just select an appropriate input oscillator.
This is a spectacularly dumb idea. There are a hundred better ways to implement frequency modulation from simple analog circuits to full software defined radio. This is a middle ground that no one asked for but the idea was just so tempting to me and I couldn’t find a single technical reason not to do it.
I won’t bury the lede – I built the darn thing and it’s a great fox transmitter. Easy to configure just by editing a text file, extra GPIO for adding external devices, open source hardware and software so you can tinker to your heart’s content. It’s great, you should buy one. They’re in stock and shipping right now.