The retrofitting itself was quite the job; drilling six mounting holes and one one-inch feed through hole in the PA cavity, mounting the new feed through housing, rewiring the high voltage connection to the tube and back to the HV bleeder assembly, etc.\u00a0 What with all of the drilling, sawing, filing, deburring, and whatnot, I began to wonder if the transmitter would ever run again.\u00a0 This is the transmitter before the modification:<\/p>\n\n\n\n This is the old high voltage feed through hole, arc mark clearly evident.<\/p>\n\n\n\n This is the modified feed through\/bypass configuration.<\/p>\n\n\n\n While doing this work, I removed the tube and put a plastic sheet in the bottom of the PA cavity and around the HV parts at the bottom of the transmitter.\u00a0 Somehow, getting aluminum filings in the tube socket seemed like a bad idea.\u00a0 I also thoroughly vacuumed out the entire transmitter once all of the metal work was done.<\/p>\n\n\n\n I removed the Kapton capacitor plates from the old feed-through arrangement and reinstalled the Teflon insulating plates to keep the air flow out of the tube cavity going in the correct direction.\u00a0 The new capacitor looks very beefy, perhaps it will never fail again.<\/p>\n\n\n\n Once the installation work was done, I brought up the transmitter first with no screen and no connection to the tube anode.\u00a0 Then with the tube connected, and finally with the screen supply turned on.\u00a0 The tuning needed a brief touch up but all in all, the transmitter came up and ran well with the new feed-through arrangement.<\/p>\n","protected":false},"excerpt":{"rendered":" In the previous post, the issue with the WVOS-FM transmitter was detailed: The PA feed through\/bypass capacitor had arced to the PA cavity causing lots of unwanted off-air time. When I went to order the replacement parts, of course, they were not available. It seems that Broadcast Electronics changed the design of its transmitters in … Continue reading Modifying the old Broadcast Electronics Transmitter<\/span><\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[82,15],"class_list":["post-7139","post","type-post","status-publish","format-standard","hentry","category-tech-stuff","tag-fm","tag-fm-transmitters"],"_links":{"self":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/7139","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/comments?post=7139"}],"version-history":[{"count":9,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/7139\/revisions"}],"predecessor-version":[{"id":11346,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/7139\/revisions\/11346"}],"wp:attachment":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/media?parent=7139"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/categories?post=7139"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/tags?post=7139"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"Broadcast](\"https:\/\/www.engineeringradio.us\/blog\/wp-content\/uploads\/2013\/08\/BE-FM3_5A-pa-cavity-400x600.jpg\")
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