{"id":428,"date":"2017-04-02T22:28:49","date_gmt":"2017-04-02T20:28:49","guid":{"rendered":"http:\/\/chaosgeordend.nl\/wordpress\/?p=428"},"modified":"2017-04-29T22:36:12","modified_gmt":"2017-04-29T20:36:12","slug":"a-simple-time-domain-reflectometer","status":"publish","type":"post","link":"https:\/\/www.chaosgeordend.nl\/wordpress\/2017\/04\/02\/a-simple-time-domain-reflectometer\/","title":{"rendered":"A simple Time Domain Reflectometer"},"content":{"rendered":"


\n\"Time<\/a>
\n<\/p>\n

I built the simple signal generator described in Electronic Design<\/a>. The same circuit you find on ZL1NC<\/a> and epanorama<\/a>. Together with an Oscilloscope it can be used to find a cable fault as described in this All about Circuits article<\/a>.
\nThe 74AC14 SMD is mounted on the board its trace side. All other parts are through-hole. Most parts were salvaged from old electronics. You can adapt the PCB to your needs.<\/p>\n

<\/p>\n

The board is powered with three alkaline AA cells. A Digital Oscilloscope, OpenHantek<\/a>, and a battery powered laptop were used in the, ahem, ad-hoc test setup<\/a>. From the five (10ns, 50ns, 200ns, 1µs, 5µs) options only the 10ns and 200ns were used. The 40MHz bandwith of the 2090 DSO was, as expected, insufficient<\/a> for checking a two meter long cable. After all, this was an experiment out of curiosity.<\/p>\n

On YouTube you can find this instruction video<\/a> by W2AEW<\/a>. He gives a clear explanation. And has a better scope too :-)<\/p>\n

Set the oscilloscope probe to 10x as the 1x option limits the bandwith. See the Electrical Engineering post<\/a> for example.<\/p>\n

Download the Eagle board and schematic files<\/a> (50kB zip).<\/p>\n


\n\"Time<\/a>
\n
\n\"Time<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

I built the simple signal generator described in Electronic Design. The same circuit you find on ZL1NC and epanorama. Together with an Oscilloscope it can be used to find a cable fault as described in this All about Circuits article. The 74AC14 SMD is mounted on the board its trace side. All other parts are … <\/p>\n

Continue reading “A simple Time Domain Reflectometer”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[33,31],"tags":[],"class_list":["post-428","post","type-post","status-publish","format-standard","hentry","category-eagle","category-electronicaelectronics"],"_links":{"self":[{"href":"https:\/\/www.chaosgeordend.nl\/wordpress\/wp-json\/wp\/v2\/posts\/428","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.chaosgeordend.nl\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.chaosgeordend.nl\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.chaosgeordend.nl\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.chaosgeordend.nl\/wordpress\/wp-json\/wp\/v2\/comments?post=428"}],"version-history":[{"count":34,"href":"https:\/\/www.chaosgeordend.nl\/wordpress\/wp-json\/wp\/v2\/posts\/428\/revisions"}],"predecessor-version":[{"id":472,"href":"https:\/\/www.chaosgeordend.nl\/wordpress\/wp-json\/wp\/v2\/posts\/428\/revisions\/472"}],"wp:attachment":[{"href":"https:\/\/www.chaosgeordend.nl\/wordpress\/wp-json\/wp\/v2\/media?parent=428"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.chaosgeordend.nl\/wordpress\/wp-json\/wp\/v2\/categories?post=428"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.chaosgeordend.nl\/wordpress\/wp-json\/wp\/v2\/tags?post=428"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}