{"id":337,"date":"2014-11-30T21:37:03","date_gmt":"2014-12-01T02:37:03","guid":{"rendered":"http:\/\/paulcarbone.com\/blog\/?p=337"},"modified":"2015-05-09T10:41:19","modified_gmt":"2015-05-09T15:41:19","slug":"tek-453","status":"publish","type":"post","link":"https:\/\/paulcarbone.com\/blog\/tek-453\/","title":{"rendered":"Tek 453"},"content":{"rendered":"<p><a href=\"http:\/\/paulcarbone.com\/blog\/wp-content\/uploads\/2014\/11\/IMG_3520.jpg\"><img loading=\"lazy\" class=\"alignnone size-full wp-image-420\" src=\"https:\/\/paulcarbone.com\/blog\/wp-content\/uploads\/2014\/11\/IMG_3520.jpg\" alt=\"IMG_3520\" width=\"3264\" height=\"2448\" srcset=\"https:\/\/paulcarbone.com\/blog\/wp-content\/uploads\/2014\/11\/IMG_3520.jpg 3264w, https:\/\/paulcarbone.com\/blog\/wp-content\/uploads\/2014\/11\/IMG_3520-300x225.jpg 300w, https:\/\/paulcarbone.com\/blog\/wp-content\/uploads\/2014\/11\/IMG_3520-1024x768.jpg 1024w, https:\/\/paulcarbone.com\/blog\/wp-content\/uploads\/2014\/11\/IMG_3520-400x300.jpg 400w\" sizes=\"(max-width: 3264px) 100vw, 3264px\" \/><\/a><\/p>\n<p>This was actually the first scope I got as &#8220;an Adult&#8221;.\u00a0 I think I paid about $100 for it about 6 years ago.\u00a0 Since then, it&#8217;s been my daily use scope, since it fits atop a rolling art-cart under my bench.<\/p>\n<p>Everything works great, except the B sweep only triggers on &#8216;starts after delay&#8217;, not &#8216;triggerable after delay&#8217;, which means there&#8217;s something fishy towards the front end of the B trigger circuit.<\/p>\n<p>Great write-up of 454 triggering diagnosis <a href=\"http:\/\/www.antiqueradios.com\/forums\/viewtopic.php?f=8&amp;t=247286\">here<\/a>. Punch-line: it was the tunnel-diode.<\/p>\n<ul>\n<li><a href=\"http:\/\/en.wikipedia.org\/wiki\/Tunnel_diode\">Wikipedia Entry<\/a><\/li>\n<li><a href=\"http:\/\/w140.com\/tekwiki\/wiki\/Tunnel_diodes\">tekWiki<\/a> on tunnel diodes<\/li>\n<li>replacement for 4.7ma tunnel diodes <a title=\"type GI304A tunnel diodes on eBay\" href=\"http:\/\/www.ebay.com\/sch\/i.html?_odkw=GI304A&amp;_from=R40&amp;_osacat=0&amp;_from=R40&amp;_trksid=p2045573.m570.l1313.TR0.TRC0.H0.XGI304A+diode&amp;_nkw=GI304A+diode&amp;_sacat=0\">available on eBay<\/a>, type GI304A, 10 pack en route.<\/li>\n<\/ul>\n<p>Also suspected Nuvistor v633, type <a href=\"http:\/\/paulcarbone.com\/blog\/wp-content\/uploads\/2014\/11\/83931.pdf\">8393<\/a>.\u00a0 Substitution with a claimed-good tube didn&#8217;t change the issue, so I&#8217;m suspecting it less, but unfortunately I can&#8217;t locate the test parameters for the the 8393.<br \/>\nFound it for the\u00a0<a href=\"http:\/\/paulcarbone.com\/blog\/wp-content\/uploads\/2014\/11\/6cw4-rca1963.pdf\">6cw4<\/a> (same pin-out?)<br \/>\n<em>Tube\u00a0\u00a0\u00a0 Plate\u00a0 Bias \u00a0 Fil.\u00a0\u00a0\u00a0 Meter\u00a0\u00a0 Sig.\u00a0\u00a0\u00a0\u00a0 Selectors\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 R.P.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Remarks<\/em><br \/>\n6CW4\u00a0 C\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 7L \u00a0 \u00a0 6.3\u00a0\u00a0 32\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 4\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 03050-0010-706\u00a0\u00a0\u00a0 1430\u00a0\u00a0 \u00a0\u00a0 Tr;X4.<\/p>\n<p><a title=\"8393 datasheet\" href=\"http:\/\/w140.com\/8393.pdf\" target=\"_blank\">Boom<\/a> &#8211; An 8393 is a 7586 w\/ a 13.5v filament.\u00a0 So, for the TT-1:<br \/>\n<em>Tube\u00a0\u00a0\u00a0 Plate\u00a0 Bias \u00a0 Fil.\u00a0\u00a0\u00a0 Meter\u00a0\u00a0 Sig.\u00a0\u00a0\u00a0\u00a0 Selectors\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 R.P.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Remarks<\/em><br \/>\n8393\u00a0 O \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 7L \u00a0 \u00a0 12 \u00a0 36 \u00a0\u00a0\u00a0\u00a0 \u00a0 4\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 03050-0010-706\u00a0\u00a0\u00a0 1140 \u00a0 \u00a0\u00a0 Tr;X4.<\/p>\n<p><strong>UPDATE 5\/3:<\/strong> Everything around that Nuvistor seems OK, but nothing is coming out of it, with either the original or replacement.\u00a0 They both test dead.\u00a0 So either:<br \/>\n1) I&#8217;m testing them wrong, and it&#8217;s something else in the circuit, or<br \/>\n2) I have two bad 8393s.<br \/>\nreplacements en route, 3 for $45.\u00a0 Damn these things are getting expensive.<\/p>\n<p>I also realized that this Nuvistor is a part of the signal chain when in XY mode, which I could never get working.<\/p>\n<p><strong>UPDATE 5\/8:<\/strong> Replacing v633 Nuvistor fixed the X\/Y mode, but &#8216;B&#8217; is still not triggering on it&#8217;s own, so there&#8217;s still some drama in the triggering circuit.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>This was actually the first scope I got as &#8220;an Adult&#8221;.\u00a0 I think I paid about $100 for it about 6 years ago.\u00a0 Since then, it&#8217;s been my daily use scope, since it fits atop a rolling art-cart under my &hellip; <a href=\"https:\/\/paulcarbone.com\/blog\/tek-453\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[26],"tags":[32,31],"table_tags":[],"_links":{"self":[{"href":"https:\/\/paulcarbone.com\/blog\/wp-json\/wp\/v2\/posts\/337"}],"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=337"}],"version-history":[{"count":14,"href":"https:\/\/paulcarbone.com\/blog\/wp-json\/wp\/v2\/posts\/337\/revisions"}],"predecessor-version":[{"id":422,"href":"https:\/\/paulcarbone.com\/blog\/wp-json\/wp\/v2\/posts\/337\/revisions\/422"}],"wp:attachment":[{"href":"https:\/\/paulcarbone.com\/blog\/wp-json\/wp\/v2\/media?parent=337"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/paulcarbone.com\/blog\/wp-json\/wp\/v2\/categories?post=337"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/paulcarbone.com\/blog\/wp-json\/wp\/v2\/tags?post=337"},{"taxonomy":"table_tags","embeddable":true,"href":"https:\/\/paulcarbone.com\/blog\/wp-json\/wp\/v2\/table_tags?post=337"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}