Current is Force and Mechanical Filters It might surprise you to learn that some radios contain moving parts, even the solid- state one that's sitting in my shack. I installed a mechanical filter the other day and it turns out that the story on how this works is mind boggling if you've never come across Richard Adler and Zenith. While we're on the subject, we look at the "goodness" of a filter and explore what this has to do with the 17th letter in the Alphabet. Foundations of Amateur Radio is a weekly podcast about the 1000 activities that make up the community of radio amateurs across the globe. You can listen to it on-air, on-demand or on-line. The podcast is available via iTunes, via Google and can be found by searching for my callsign VK6FLAB. You can also visit the website at http://podcasts.itmaze.com.au/foundations/ where you'll find this and all the other episodes ready to go. Onno VK6FLAB
