{"id":7507,"date":"2021-11-06T22:11:00","date_gmt":"2021-11-06T11:11:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2021\/11\/06\/m0ntvs-crystal-filters-for-the-fearful-video\/"},"modified":"2025-07-22T18:04:30","modified_gmt":"2025-07-22T08:04:30","slug":"m0ntvs-crystal-filters-for-the-fearful-video","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2021\/11\/06\/m0ntvs-crystal-filters-for-the-fearful-video\/","title":{"rendered":"M0NTV&#8217;s &#8220;Crystal Filters for the Fearful&#8221; (video)"},"content":{"rendered":"<p><iframe loading=\"lazy\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen=\"\" frameborder=\"0\" height=\"247\" src=\"https:\/\/www.youtube.com\/embed\/vVioj-QkaVo?rel=0\" title=\"YouTube video player\" width=\"440\"><\/iframe><\/p>\n<div><\/div>\n<div><b>I really liked Nick M0NTV&#8217;s approach to making a crystal filter (see video above). He really simplifies a process that desperately needs simplification. I remember when I was building my first superhet receiver, I came across Doug DeMaw&#8217;s schematic for a crystal tester that would allow me to properly build the filter. But the piece of test gear was far more complicated than the receiver I was building. I never built Doug&#8217;s device. <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>Nick&#8217;s technique is simpler even than the G3UUR method that many of us have been using for years. Nick dispenses &#8212; wisely I think &#8212; with the need to calculate motional parameters, Q, and equivalent series resistance. This also eliminates the need to fidget around with the design software such as Dishal or AADE. <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>Nick uses the Cohn topology (good choice) and uses kind of an &#8220;informed cut-and-try&#8221; technique to come up with the capacitor values. <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>Filter impedance is determined with series trimmer resistors and the NanoVNA to watch the resulting passband. Nick says this is a Charlie Morris ZL2CTM suggestion. It obviously works very well &#8212; the ripple that would result from impedance mismatch is eliminated. <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>Nick&#8217;s determination of the best turns ratio for the impedance matching transformers is brilliant.<\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>Nick apologizes for what he says is a long video. But it is only 30 minutes or so long, and if you are going to build your own superhet or SSB filter rig, it is well worth watching. <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>Three cheers for Nick and for Charlie! Thanks guys! <\/b><\/div>\n","protected":false},"excerpt":{"rendered":"<p>I really liked Nick M0NTV&#8217;s approach to making a crystal filter (see video above). He really simplifies a process that desperately needs simplification. I remember when I was building my first superhet receiver, I came across Doug DeMaw&#8217;s schematic for a crystal tester that would allow me to properly build the filter. But the piece &hellip; <a href=\"https:\/\/www.homebrewradio.us\/blog\/2021\/11\/06\/m0ntvs-crystal-filters-for-the-fearful-video\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;M0NTV&#8217;s &#8220;Crystal Filters for the Fearful&#8221; (video)&#8221;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7,16,350,495,23,57,71],"tags":[],"class_list":["post-7507","post","type-post","status-publish","format-standard","hentry","category-demaw-doug","category-filters","category-morris-charlie","category-nano-uk-new-zealand","category-ssb","category-superhet-receivers","category-test-gear"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/7507","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/comments?post=7507"}],"version-history":[{"count":1,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/7507\/revisions"}],"predecessor-version":[{"id":11429,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/7507\/revisions\/11429"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=7507"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=7507"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=7507"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}