Part 1 of a 3-part mini-series where Nick (M0NTV) explains and demonstrates how he designs, builds and tests an LC filter. The two websites referenced are: rf-tools.com/lc-filter/ www.toroids.info
Nick - a superb video, incredibly well explained. Looking forward to Part 2 and Part 3 now! It's good that you showed online calculators too, as it's accessible to all of us, and as you say, "Why reinvent the wheel?". Trystan
Hi Bob, thanks for watching and getting in touch. I'm glad you found it helpful. All the very best to you. It's a fascinating hobby with countless rabbit holes to explore! Enjoy! 73 M0NTV
Great video. One thing I find little to no info on is how to select components depending on the power it must be able to handle. I know the websites you mention, but how to select the right toroids and capacitors for 5W, 100W or 1.5KW? And what wire thickness to use for the different power levels?
Thanks Cedric. You might find this article by the late great George Dobbs helpful: pdf4pro.com/amp/view/a-short-guide-to-harmonic-filter-for-qrp-transmitter-18ac31.html Essentially, as you'd expect you'll need larger cores and perhaps even multiple cores to handle greater power levels. Wire thickness is a trade off between using the thickest wire you can to get the required number of turns to cover 3/4 or 4/5 of the toroid. Check out other people's designs and experiment! Personally I've never built an LC filter to handle more than 100W (I'm more of a QRP guy) but clearly it can be done. Have fun!
