yellow Victoreen civil defense portable counters<\/a> from the 1950s. I actually found a mating 3-pin female connector in my junkbox, which is good, since I have no idea where I’d look otherwise. (The alternative is cannibalizing an octal tube socket for individual pin-grippers, generally by crushing a Bakelite socket in a vice until it crumbles.) Including the pins, the tube is just under 4″ long and 0.625″ in diameter. I’ll have to build a probe housing for it eventually, but near-term I’ll mount it in a pill bottle, of which there are legion.<\/p>\nThe top photo is a stack of three 1000-volt mica capacitors, adding up to .048 MFD. That’s about what one circuit calls out, but more is better, and I have a 1950s steatite banana plug bar into which two such stacks will go. So I’ll build a second and put them in parallel. That will get me to about 0.8 MFD, which ought to be enough. If it isn’t, I’ll see what else I can scrounge in the line of high-voltage caps.<\/p>\n
I’m modifying an old ceramic wafer switch to be a current interrupter, but I need to get a little farther along before I know if that will work. Those familiar with such switches will understand: I bent down the limit tabs so that the switch shaft can be turned continuously, and at each click current will make-and-break between the wiper and the stationary contacts. Crank it like a Model T, and you generate a series of quick DC pulses to the transformer.<\/p>\n
Or that’s the theory, anyway. We’ll see how well it works. More as it happens.<\/p>\n","protected":false},"excerpt":{"rendered":"
It still hurts like hell to lean back against anything (for latecomers, I’m working through a nasty case of shingles) so I spent a good part of today sitting on my venerable and much taped-up barstool downstairs in my shop, drowning my pain in milk-jugs full of antique electronic parts. As I mentioned yesterday, having […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7,23],"tags":[21,101],"class_list":["post-1476","post","type-post","status-publish","format-standard","hentry","category-daybook","category-ideasandanalysis","tag-electronics","tag-steampunk"],"_links":{"self":[{"href":"http:\/\/www.contrapositivediary.com\/index.php?rest_route=\/wp\/v2\/posts\/1476","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.contrapositivediary.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.contrapositivediary.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.contrapositivediary.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/www.contrapositivediary.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1476"}],"version-history":[{"count":1,"href":"http:\/\/www.contrapositivediary.com\/index.php?rest_route=\/wp\/v2\/posts\/1476\/revisions"}],"predecessor-version":[{"id":1477,"href":"http:\/\/www.contrapositivediary.com\/index.php?rest_route=\/wp\/v2\/posts\/1476\/revisions\/1477"}],"wp:attachment":[{"href":"http:\/\/www.contrapositivediary.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1476"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.contrapositivediary.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1476"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.contrapositivediary.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1476"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
![\"CapStack500Wide.jpg\"](\"http:\/\/www.contrapositivediary.com\/wp-content\/uploads\/2010\/09\/CapStack500Wide.jpg\")
<\/p>\n![\"VictoreenGeigerTube500Wide.jpg\"](\"http:\/\/www.contrapositivediary.com\/wp-content\/uploads\/2010\/09\/VictoreenGeigerTube500Wide.jpg\")
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