My first time ever playing with tunnel diodes, believe it or not 🤷🏼♂️😂
They start conducting immediately, but not much, then suddenly crossing some current level, they switch on super-fast, this one is measured in nanoseconds!
Decreasing the current they’ll eventually switch off again, equally fast, delivering a Schmitt-Trigger response.
They’re sensitive devices, you can damage them by using a diode tester on the multimeter, so be careful. They’re also ESD sensitive, so make sure to use a grounding wristband 🙂
My living room as an antenna test chamber 😂 Well, it was a rainy day, couldn’t set it up outside.
I’m testing a 2.4GHz dish, meant for WiFi links, but as it turns out, it has a decent match at 1420MHz so it’s actually usable as a Hydrogen Line radio telescope antenna.
Traversing in front of it, you can see its impedance (S11 for the experts) change. This happens because I’m affecting its near field. In human understandable terms: being sufficiently close to the antenna affects how it performs.
With my newly acquired LNA, this will likely end up being a much more portable Hydrogen Line radio telescope, I have high expectations 😃