{"id":145,"date":"2014-08-17T18:24:21","date_gmt":"2014-08-17T23:24:21","guid":{"rendered":"http:\/\/paulcarbone.com\/blog\/?p=145"},"modified":"2015-02-17T21:26:05","modified_gmt":"2015-02-18T02:26:05","slug":"general-radio-1650-wheatstone-bridge","status":"publish","type":"post","link":"https:\/\/paulcarbone.com\/blog\/general-radio-1650-wheatstone-bridge\/","title":{"rendered":"General Radio 1650 Wheatstone Bridge"},"content":{"rendered":"

This piece is one of several I picked up at an estate sale in June.\u00a0 It’s late 60’s \/ early 70’s vintage, making it one of the newer pieces in my collection (and by far the newest thing I’d picked up that day).<\/p>\n

This killed two birds with one stone:\u00a0 I’ve wanted an Impedance Bridge for quite a while, and oddly enough, I didn’t own any General Radio gear until now.<\/p>\n

This is actually an after picture<\/p>\n

\"DSC_0150\"<\/p>\n

It was in pretty good condition with the exception of some flaking paint, which was due to…\"DSC_0134\"<\/a> D-cell batteries leaking their corrosive innards all over.\u00a0 Boo..<\/p>\n

The plastic sleeve & batteries were fused together.\u00a0 I pulled the whole assembly and screwed it back onto the chassis facing out, in order to try to get some leverage.\u00a0 \"DSC_0137\"<\/a><\/p>\n

The tube snapped as I was trying to separate it, but fortunately the contact was salvageable.\"DSC_0138\"<\/a><\/p>\n

Here’s the metal disc that’s supposed to keep batteries from leaking all over the inside of your instrument.\u00a0 Good going there, metal disc.\u00a0 You had ONE job. \"DSC_0139\"<\/a><\/p>\n

These batteries are so old, they were made in America.\u00a0 Right up the road in Tarrytown, actually. \"DSC_0141\"<\/a><\/p>\n

Paper towel tube to the rescue.\"DSC_0144\"<\/a><\/p>\n

 <\/p>\n

Wrapped carefully in extra-wide gaffers tape for structural integrity.\u00a0 Because gaff.<\/p>\n

\"DSC_0148\"<\/a><\/p>\n

Reading 980 ohms on a 1k resistor.
\n\"DSC_0151\"<\/a><\/p>\n

I tested a cap or two as well which seemed to work and indicate that the internal oscillator is functioning.\u00a0 It’s an interesting, if not somewhat fickle instrument.\u00a0 The sensitivity control is overly sensitive, which I suppose bears some investigation.\u00a0 It’s not nearly as foolproof as a modern LCR meter, you need to have some idea of the value you’re expecting, or it’s possible to get a false reading.<\/p>\n","protected":false},"excerpt":{"rendered":"

This piece is one of several I picked up at an estate sale in June.\u00a0 It’s late 60’s \/ early 70’s vintage, making it one of the newer pieces in my collection (and by far the newest thing I’d picked … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[16],"tags":[],"table_tags":[],"_links":{"self":[{"href":"https:\/\/paulcarbone.com\/blog\/wp-json\/wp\/v2\/posts\/145"}],"collection":[{"href":"https:\/\/paulcarbone.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/paulcarbone.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/paulcarbone.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/paulcarbone.com\/blog\/wp-json\/wp\/v2\/comments?post=145"}],"version-history":[{"count":4,"href":"https:\/\/paulcarbone.com\/blog\/wp-json\/wp\/v2\/posts\/145\/revisions"}],"predecessor-version":[{"id":179,"href":"https:\/\/paulcarbone.com\/blog\/wp-json\/wp\/v2\/posts\/145\/revisions\/179"}],"wp:attachment":[{"href":"https:\/\/paulcarbone.com\/blog\/wp-json\/wp\/v2\/media?parent=145"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/paulcarbone.com\/blog\/wp-json\/wp\/v2\/categories?post=145"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/paulcarbone.com\/blog\/wp-json\/wp\/v2\/tags?post=145"},{"taxonomy":"table_tags","embeddable":true,"href":"https:\/\/paulcarbone.com\/blog\/wp-json\/wp\/v2\/table_tags?post=145"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}