Hi Doug, very good summaries of your classes! I've linked them on our club website in case it helps other aspiring hams get started. scarcs.ca/blog/2025-11...

Glad it helped. With just the first two points, you can get a good qualitative feel for a lot of LC filters (series, parallel, mixed) just by asking: which path will the low, mid, and high frequencies take.

Exactly. If you put the capacitor and inductor between Vin and Vout instead, then it would be the opposite: mid range would get through to Vout, but the highs and lows would be blocked.

... But somewhere in the middle, there's a frequency that's able to get through to the dump, so less of that one makes it to Vout. That particular frequency depends on. The values of L and C.

So... By putting a capacitor and inductor in series, you make it hard for both low and high frequencies to get dumped, so they reach Vout more easily...

3. In your diagram, the line below the inductor and capacitor is like a sink where you can "dump" parts of the signal you don't want to reach the Vout side. If the route to the dump is easy to take, parts of the signal will take it, otherwise, it'll continue straight to Vout.

Three things to understand first:

1. An inductor makes it hard for current at high frequencies to get through.

2. A capacitor makes it hard for currents at low frequencies to get through.

I can expand on these if you need.

...

Good point. I just set up a reminder of this fact on our shelf.

And a conversation on Canadaland: Nice Try, Bluesky (Still Bitter Over Twitter)

www.canadaland.com/podcast/1061...

Cory Doctorrow's Bluesky and enshittification:
"Bluesky lacks [...] the ability to leave [it] and go to another host and continue to talk to the people I've entered into community with there."

pluralistic.net/2024/11/02/u...