Improving the selectivity and weak signal sensitivity of a crystal set.
Discussion at http://theradioboard.com/rb/viewtopic.php?t=6660
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)