{"id":4942,"date":"2012-04-30T08:00:27","date_gmt":"2012-04-30T12:00:27","guid":{"rendered":"http:\/\/www.engineeringradio.us\/blog\/?p=4942"},"modified":"2023-04-29T08:54:44","modified_gmt":"2023-04-29T12:54:44","slug":"the-broadcast-electronics-fw-30-automatic-exciter-switcher","status":"publish","type":"post","link":"https:\/\/www.engineeringradio.us\/blog\/2012\/04\/the-broadcast-electronics-fw-30-automatic-exciter-switcher\/","title":{"rendered":"The Broadcast Electronics FW-30 automatic exciter switcher"},"content":{"rendered":"\n

This is a neat piece of kit, designed to save those late-night\/early morning callouts, which is the ultimate goal of all broadcast engineers, or at least it should be.\u00a0 This seems like a really good idea, however, BE has discontinued the product line, and the last manual update is from 2000.<\/p>\n\n\n\n

\"Broadcast<\/a>
Broadcast Electronics FW-30 exciter switcher innards<\/figcaption><\/figure>\n\n\n\n

A small four-port coax switch is located next to the power supply transformer.\u00a0 This is controlled by the circuit board.\u00a0 The circuit board senses a loss of excitation by detecting a forward power level below the threshold set on the board. The power sample comes from the exciter forward power remote metering terminals.\u00a0 Thus, it can be used with any exciter(s) that have a remote forward power sample.<\/p>\n\n\n\n

\"BE<\/a>
BE FW30 exciter switcher block diagram<\/figcaption><\/figure>\n\n\n\n

The idea is to use the RF fault function output of the FX-30 (later FX-50) exciter to automatically switch from a faulted exciter to one that is working.\u00a0 Finally, it can be hooked to a remote control for manual switching.\u00a0 The unused exciter is muted and routed to a dummy load mounted on the back of the unit.<\/p>\n\n\n\n

\"Broadcast<\/a>
Broadcast Electronics FW-30 front, mid 1980’s BE blue<\/figcaption><\/figure>\n\n\n\n

An alternate configuration would be to route the backup exciter to the backup transmitter instead of the dummy load.\u00a0 This would create the best redundancy on a limited equipment budget.\u00a0 It also has a battery bank designed to hold the last state of the unit through a power outage.\u00a0 As we have a good-sized UPS powering the remote control, STLs, and satellite receivers, the batteries are not needed.<\/p>\n\n\n\n

On the face of it, a pretty good idea.  I have had a few exciters fail over the years, which normally means the backup transmitter is placed in service by remote.<\/p>\n\n\n\n

I did download the manual, but since it is currently listed on the BE website, it’s probably not a good idea to post the schematic.\u00a0 Suffice to say, it is a tad bit complicated what with all the CMOS logic and that.\u00a0 It is very possible to duplicate the functions of this equipment with a simple RF forward power sample and set a failure threshold with a comparator circuit.\u00a0 Hook that to a small four-port coax switch and a couple of RF mute\/un-mute commands to each exciter and: Viola!\u00a0 Automatic exciter switching!<\/p>\n\n\n\n

Perhaps a good rainy day project.<\/p>\n","protected":false},"excerpt":{"rendered":"

This is a neat piece of kit, designed to save those late-night\/early morning callouts, which is the ultimate goal of all broadcast engineers, or at least it should be.\u00a0 This seems like a really good idea, however, BE has discontinued the product line, and the last manual update is from 2000. A small four-port coax … Continue reading The Broadcast Electronics FW-30 automatic exciter switcher<\/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":[15],"class_list":["post-4942","post","type-post","status-publish","format-standard","hentry","category-tech-stuff","tag-fm-transmitters"],"_links":{"self":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/4942","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=4942"}],"version-history":[{"count":10,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/4942\/revisions"}],"predecessor-version":[{"id":11610,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/4942\/revisions\/11610"}],"wp:attachment":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/media?parent=4942"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/categories?post=4942"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/tags?post=4942"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}