https://stream.echo6.co/videos/watch/dce92a31-cd43-4f08-bb0f-71864b415b0e It was 20 cents in a charity shop so how could I resist? It's a 40 year old high pass filter in original packaging. It would have sold in its thousands to protect TV receivers against strong signals from nearby CB or amateur transmitters. In this video I examine what's inside it. PS: If you liked this video please consider supporting Amateur Radio VK3YE by: Subscribing on YouTube,, Checking my books page at https://books.vk3ye.com, Shopping on Amazon via: https://amzn.to/3iiDQXv, or, Shopping on eBay via: https://ebay.us/i9DuWP (then if you buy something I'll get a small commission at no cost to you) Sat, 13 Jun 2026 18:18:26 GMT https://validator.w3.org/feed/docs/rss2.html PeerTube - https://stream.echo6.co https://stream.echo6.co/client/assets/images/icons/icon-512x512.png https://stream.echo6.co/videos/watch/dce92a31-cd43-4f08-bb0f-71864b415b0e All rights reserved, unless otherwise specified in the terms specified at https://stream.echo6.co/about and potential licenses granted by each content's rightholder.