{"id":2244,"date":"2012-03-01T15:05:55","date_gmt":"2012-03-01T21:05:55","guid":{"rendered":"http:\/\/w0ep.us\/OM\/?p=2244"},"modified":"2012-03-01T15:16:53","modified_gmt":"2012-03-01T21:16:53","slug":"more-on-unfinished-receiver","status":"publish","type":"post","link":"http:\/\/w0ep.us\/OM\/?p=2244","title":{"rendered":"More on unfinished receiver"},"content":{"rendered":"<p>[Today&#8217;s run: 2 miles]<\/p>\n<p>I&#8217;ve gotten connected to an email reflector about the HBR receivers and I see there is a lot of good information.<\/p>\n<p>I&#8217;ve been asked to make some pictures available so that people can see what it looks like.\u00a0\u00a0 This blog post will be a repository for that info.<\/p>\n<p><a href=\"http:\/\/w0ep.us\/OM\/?attachment_id=2246\" rel=\"attachment wp-att-2246\">Underside Left<\/a><br \/>\n<a href=\"http:\/\/w0ep.us\/OM\/?attachment_id=2247\" rel=\"attachment wp-att-2247\">Underside Right<\/a><br \/>\n<a href=\"http:\/\/w0ep.us\/OM\/?attachment_id=2248\" rel=\"attachment wp-att-2248\">Bandswitch &#8211; front end<\/a><\/p>\n<p>My posts to eham.net (<a href=\"http:\/\/www.eham.net\/ehamforum\/smf\/index.php\/topic,80680.0.html\">link to eham.net discussion<\/a>) contains links to some of the same pictures and my description of what I think the tubes are doing:<\/p>\n<blockquote><p>Thanks for all the advice. This thing has some indications<br \/>\nof having worked (dial calibration marks, etc.) but<br \/>\nalso has loose ends. So it may have been an unsatisfactory<br \/>\nattempt. Makes an interesting puzzle!<\/p>\n<p>Tube line up and signal path (as far as I can tell so far)<\/p>\n<p>(underside, part 1 <a href=\"http:\/\/w0ep.us\/radio_stuff\/unkown_rx\/GEDC0205.JPG\">http:\/\/w0ep.us\/radio_stuff\/unkown_rx\/GEDC0205.JPG<\/a> )<\/p>\n<p>&nbsp;<\/p>\n<p>Slug tuned coils selected by bandswitch along with a<br \/>\none-section air variable (about 1 in. dia, knob labelled &#8220;antenna&#8221;)<br \/>\nIt appears that some coils are not attached.<\/p>\n<p>6au6<\/p>\n<p>More bandswitched coils. Some small air-variables in this<br \/>\nneighborhood but they are not connected to anything!<\/p>\n<p>6cs6<\/p>\n<p>nearby is a 6ak5\u00a0 and some slug tuned<br \/>\ncoils also bandswitched. I believe this is the LO.<\/p>\n<p>Single section air-variable cap on the top deck, a bit larger<br \/>\nin dia. (1.25&#8243; ?) and about 2 inches long (20 plates?)<br \/>\nwhich is attached to gear drive and main tuning.<\/p>\n<p>IF can<\/p>\n<p>6be6<\/p>\n<p>IF can<\/p>\n<p>1330 and 8340 crystals attached to<br \/>\na switch marked for USB\/LSB nearby<br \/>\nis a 6ak5<\/p>\n<p>IF can<\/p>\n<p>6cb6<\/p>\n<p>IF can<\/p>\n<p>(underside part 2 <a href=\"http:\/\/w0ep.us\/radio_stuff\/unkown_rx\/GEDC0206.JPG \">http:\/\/w0ep.us\/radio_stuff\/unkown_rx\/GEDC0206.JPG <\/a>)<\/p>\n<p>6t8<\/p>\n<p>output to headphones<\/p>\n<p>audio xfmr (I think it is not even connected)<\/p>\n<p>6aq5<\/p>\n<p>In the neighborhood of the 6t8 is a 6c4 and a<br \/>\n1&#8217;x1&#8242; can shaped thing. from that collection comes the<br \/>\nBFO signal, loosely coupled by wire twisted in<br \/>\nnear that last IF can.<\/p>\n<p>6au6 with a 100 kHz crystal which appears<br \/>\nto inject calibrator signal into the front end.<\/p>\n<p>Tubes left over that I don&#8217;t yet know the function of: 12au7, 6ak5<\/p>\n<p>And there is a 5y3gt rectifier tube.<\/p>\n<p>(topside <a href=\"http:\/\/w0ep.us\/radio_stuff\/unkown_rx\/GEDC0213.JPG\">http:\/\/w0ep.us\/radio_stuff\/unkown_rx\/GEDC0213.JPG<\/a> )<\/p>\n<p>The front panel is nicely painted with factory-type lettering.<\/p>\n<p>(front <a href=\"http:\/\/w0ep.us\/radio_stuff\/unkown_rx\/GEDC0218.JPG\">http:\/\/w0ep.us\/radio_stuff\/unkown_rx\/GEDC0218.JPG<\/a> )<\/p>\n<p>Controls on the front &#8212;<br \/>\nknobs look like from a xxxxBC-348xxxx (correction, BC-312),<br \/>\narrows and sometimes word printed on knobs<br \/>\n(left to right)<\/p>\n<p>ANTENNA<br \/>\nSIDEBAND (upper\/lower) (knob says &#8220;crystal&#8221; and has an arrow)<br \/>\nBand switch (80M 40M 20M 15M 10M)<br \/>\nR.F. GAIN<br \/>\nA.V.C. (switch: up-HIGH\/down-LOW)<br \/>\nC.W. OSC (switch: up-ON \/ down-no marking)<br \/>\nAUDIO (integral power on\/off switch)<br \/>\nPITCH<br \/>\nCALIBRATE (switch: no markings)<br \/>\nSQUELCH (integral switch)<br \/>\nPHONES (jack)<br \/>\nDIAL\/SET (little knob up near the dial which shifts<br \/>\nthe rotating thing a bit left or right)<\/p>\n<p>There is an s-meter in the upper left which is a Triplet meter<br \/>\nwith pencil marks &#8220;s-9&#8221;, &#8220;+20&#8221;, &#8220;+40&#8221; on the meter dial.<\/p>\n<p>Main tuning knob is in the center. slide-rule dial with single,<br \/>\nnarrow window and a turning mechanism actuated by the band switch<br \/>\n(mechanism is disconnected due to dial cord break). Paper<br \/>\ncover on the turned cylinder has pencil marks with ham-band<br \/>\ntype numbers.<\/p>\n<p>I will try to get some pictures. (added picture links to this post)<\/p>\n<p>Injecting a signal in the antenna I can follow it through the<br \/>\ncoils and bandswitch. It gets lost near the sideband switch.<br \/>\nBut I&#8217;m not sure if I have the main tuning set correctly to receive.<br \/>\nI&#8217;ll have to work on that some more.<\/p>\n<p>With phones plugged in, I can get some sound if I<br \/>\nmax the audio gain. I&#8217;m thinking it is self oscillation.<br \/>\nOtherwise, no static or shoosh noise at all.<\/p>\n<p>I don&#8217;t know for sure that the tubes are in the right sockets,<br \/>\nbut this is where I found them. All tubes tested ok in<br \/>\nmy ancient and dodgy tube tester. All tubes have bayonet-type<br \/>\nshields except rectifier.<\/p><\/blockquote>\n<p>A later post on eham (after discovering that the tube in the socket for the LO was incorrect)<\/p>\n<blockquote><p>I found a 6C4 in my tube collection and gave that a try.<br \/>\nIt works!<\/p>\n<p>Three settings of the bandswitch seem to work.<br \/>\nWith those settings the LO produces:<\/p>\n<p>Low &#8212; High || +1415 1st IF<br \/>\n12639 &#8212; 12926 || 14054 &#8212; 14341<br \/>\n2234 &#8212; 2601 || 3649 &#8212; 4016<br \/>\n5767 &#8212; 5976 || 7172 &#8212; 7391<\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":"<p>[Today&#8217;s run: 2 miles] I&#8217;ve gotten connected to an email reflector about the HBR receivers and I see there is a lot of good information. I&#8217;ve been asked to make some pictures available so that people can see what it looks like.\u00a0\u00a0 This blog post will be a repository for that info. Underside Left Underside [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"class_list":["post-2244","post","type-post","status-publish","format-standard","hentry","category-ham-radio"],"_links":{"self":[{"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/posts\/2244","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2244"}],"version-history":[{"count":26,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/posts\/2244\/revisions"}],"predecessor-version":[{"id":2271,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/posts\/2244\/revisions\/2271"}],"wp:attachment":[{"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2244"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2244"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2244"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}