{"id":7116,"date":"2018-01-28T20:00:26","date_gmt":"2018-01-28T20:00:26","guid":{"rendered":"http:\/\/www.bartola.co.uk\/valves\/?p=7116"},"modified":"2018-01-28T20:01:52","modified_gmt":"2018-01-28T20:01:52","slug":"valve-test-rig-with-fixed-bias","status":"publish","type":"post","link":"https:\/\/www.bartola.co.uk\/valves\/2018\/01\/28\/valve-test-rig-with-fixed-bias\/","title":{"rendered":"Valve test rig with fixed bias"},"content":{"rendered":"

My test rig for DHT\/IHT stages (and even Pentodes) has evolved over the years. Lately I settled with some nice modifications to allow testing the majority of valves I have. I use a modular socket system, nothing fancy and can add\/remove a source follower stage at the output. There is also a screen regulator in case pentodes are submitted under the mercy of the jig.<\/p>\n

Here is the simplified diagram. I added a nice fixed bias supply formed by a SMPS PCB board which delivers up to 400V, however the output is dial to about 100V. Then I use a Swenson Regulator to knock down the noise by about 100dB. A simple pot provides the voltage needed between 0 and -100V. It can be tweaked for whatever range you need. The pot is 20T wirewound so allows a fine adjustment on the bias:<\/p>\n

\"\"<\/a>For the curious builders, \"\"<\/a>here is the rig mounted on a piece of floor board:<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

My test rig for DHT\/IHT stages (and even Pentodes) has evolved over the years. Lately I settled with some nice modifications to allow testing the majority of valves I have. I use a modular socket system, nothing fancy and can add\/remove a source follower stage at the output. There is also a screen regulator in … Continue reading “Valve test rig with fixed bias”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[5],"tags":[1106,44,875,1062,1099],"class_list":["post-7116","post","type-post","status-publish","format-standard","hentry","category-valves","tag-dht-testing","tag-gyrator","tag-gyrator-pcb","tag-source-follower-pcb","tag-swenson-regulator"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p2r2tK-1QM","jetpack_likes_enabled":true,"jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/7116","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/comments?post=7116"}],"version-history":[{"count":4,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/7116\/revisions"}],"predecessor-version":[{"id":7122,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/7116\/revisions\/7122"}],"wp:attachment":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/media?parent=7116"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/categories?post=7116"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/tags?post=7116"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}