{"id":1273,"date":"2018-08-07T15:46:33","date_gmt":"2018-08-07T13:46:33","guid":{"rendered":"https:\/\/pa3csg.nl\/?page_id=1273"},"modified":"2019-05-08T08:27:24","modified_gmt":"2019-05-08T06:27:24","slug":"universal-triode-input-board","status":"publish","type":"page","link":"https:\/\/pa3csg.nl\/?page_id=1273","title":{"rendered":"Universal triode input board"},"content":{"rendered":"

To build another tube amplifier, I needed a matching to the 50 Ohm output of my solid state transceiver. It had to be universal and applicable in a normal tube amplifier. I did not bother do make it perfect on the first attempt. It should be easy to experiment with variable mica capacitors and any form of inductor, on a toroid or an air inductor. If a good match is found the mica compression trimmers can be replaced by fixed capacitors mica \/ ATC100B or whatever.<\/p>\n

The schematic can be seen below:<\/p>\n

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Note that there are no capacitors in the circuit, those capacitor values should be set experimentally. There are 6 bands and one loop-through.<\/p>\n

For initial testing there is a loop-through (the most left in the circuit diagram), this enables me to test the output and use my antenna tuner as a temporary match on the input.<\/p>\n

As relays I use most of the times the Fujitsu FTR K1CK012W relay. The relay has proven to be very sturdy. These relays are very affordable and reliable For \u20ac1,75 it is hard to find a better one. The datasheet is HERE :\u00a0 ftr-k1<\/a><\/p>\n

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The board is double sided and designed in a way the the RF part is on the top and the DC part is on the bottom. As much as possible ground-plane is on both sides. Connected with uncountable vias to provide good grounding. The top section has no solder mask, this ensures easy experimentation.<\/p>\n

The board is 15 x 15 cm in size. If you are interested in this board you can ask if I have some boards left.<\/p>\n

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NOTE<\/h3>\n

A friend of mine saw this page and informed me about the W7DS website. He offers a similar board a bit smaller than mine and without the direct connection to the input. He has a manual with some suggestions for values of the matching components for several amplifiers. He did a lot of work to sort that out. He also offers complete kits. A link is HERE<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

To build another tube amplifier, I needed a matching to the 50 Ohm output of my solid state transceiver. It had to be universal and […]<\/a><\/p>\n<\/div>","protected":false},"author":1,"featured_media":1274,"parent":0,"menu_order":22,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"categories":[38],"tags":[],"_links":{"self":[{"href":"https:\/\/pa3csg.nl\/index.php?rest_route=\/wp\/v2\/pages\/1273"}],"collection":[{"href":"https:\/\/pa3csg.nl\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/pa3csg.nl\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/pa3csg.nl\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/pa3csg.nl\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1273"}],"version-history":[{"count":7,"href":"https:\/\/pa3csg.nl\/index.php?rest_route=\/wp\/v2\/pages\/1273\/revisions"}],"predecessor-version":[{"id":1290,"href":"https:\/\/pa3csg.nl\/index.php?rest_route=\/wp\/v2\/pages\/1273\/revisions\/1290"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pa3csg.nl\/index.php?rest_route=\/wp\/v2\/media\/1274"}],"wp:attachment":[{"href":"https:\/\/pa3csg.nl\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1273"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pa3csg.nl\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1273"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pa3csg.nl\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1273"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}