{"version":"1.0","provider_name":"Johnson&#039;s Techworld","provider_url":"https:\/\/johnsonfrancis.org\/techworld","author_name":"Johnson Francis","author_url":"https:\/\/johnsonfrancis.org\/techworld\/author\/jf\/","title":"Ceramic Vacuum Tubes: High Power &amp; Rugged - Johnson&#039;s Techworld","type":"rich","width":600,"height":338,"html":"<blockquote class=\"wp-embedded-content\" data-secret=\"uyiBIg1z5m\"><a href=\"https:\/\/johnsonfrancis.org\/techworld\/ceramic-vacuum-tubes-high-power-rugged\/\">Ceramic Vacuum Tubes: High Power &amp; Rugged<\/a><\/blockquote><iframe sandbox=\"allow-scripts\" security=\"restricted\" src=\"https:\/\/johnsonfrancis.org\/techworld\/ceramic-vacuum-tubes-high-power-rugged\/embed\/#?secret=uyiBIg1z5m\" width=\"600\" height=\"338\" title=\"&#8220;Ceramic Vacuum Tubes: High Power &amp; Rugged&#8221; &#8212; Johnson&#039;s Techworld\" data-secret=\"uyiBIg1z5m\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\" class=\"wp-embedded-content\"><\/iframe><script>\n\/*! This file is auto-generated *\/\n!function(d,l){\"use strict\";l.querySelector&&d.addEventListener&&\"undefined\"!=typeof URL&&(d.wp=d.wp||{},d.wp.receiveEmbedMessage||(d.wp.receiveEmbedMessage=function(e){var t=e.data;if((t||t.secret||t.message||t.value)&&!\/[^a-zA-Z0-9]\/.test(t.secret)){for(var s,r,n,a=l.querySelectorAll('iframe[data-secret=\"'+t.secret+'\"]'),o=l.querySelectorAll('blockquote[data-secret=\"'+t.secret+'\"]'),c=new RegExp(\"^https?:$\",\"i\"),i=0;i<o.length;i++)o[i].style.display=\"none\";for(i=0;i<a.length;i++)s=a[i],e.source===s.contentWindow&&(s.removeAttribute(\"style\"),\"height\"===t.message?(1e3<(r=parseInt(t.value,10))?r=1e3:~~r<200&&(r=200),s.height=r):\"link\"===t.message&&(r=new URL(s.getAttribute(\"src\")),n=new URL(t.value),c.test(n.protocol))&&n.host===r.host&&l.activeElement===s&&(d.top.location.href=t.value))}},d.addEventListener(\"message\",d.wp.receiveEmbedMessage,!1),l.addEventListener(\"DOMContentLoaded\",function(){for(var e,t,s=l.querySelectorAll(\"iframe.wp-embedded-content\"),r=0;r<s.length;r++)(t=(e=s[r]).getAttribute(\"data-secret\"))||(t=Math.random().toString(36).substring(2,12),e.src+=\"#?secret=\"+t,e.setAttribute(\"data-secret\",t)),e.contentWindow.postMessage({message:\"ready\",secret:t},\"*\")},!1)))}(window,document);\n\/\/# sourceURL=https:\/\/johnsonfrancis.org\/techworld\/wp-includes\/js\/wp-embed.min.js\n<\/script>\n","thumbnail_url":"https:\/\/johnsonfrancis.org\/techworld\/wp-content\/uploads\/2026\/07\/Ceramic-Vacuum-Tubes-High-Power-Rugged.jpg","thumbnail_width":1280,"thumbnail_height":722,"description":"Ceramic vacuum tubes (often called metal-ceramic tubes) are specialized electron tubes that use advanced ceramics\u2014typically alumina or beryllium oxide\u2014instead of glass for their outer envelope and internal insulating structures. Because they look more like machined metal engine parts than traditional glowing glass bulbs, they are often unrecognizable as vacuum tubes to the untrained eye. Why [&hellip;]"}