{"id":426,"date":"2012-07-14T16:21:37","date_gmt":"2012-07-14T16:21:37","guid":{"rendered":"http:\/\/www.bartola.co.uk\/valves\/?p=426"},"modified":"2012-07-14T16:28:46","modified_gmt":"2012-07-14T16:28:46","slug":"4-65a-eimac","status":"publish","type":"post","link":"https:\/\/www.bartola.co.uk\/valves\/2012\/07\/14\/4-65a-eimac\/","title":{"rendered":"4-65a EIMAC"},"content":{"rendered":"

4-65a EIMAC NOS DHT<\/h1>\n

Just got a couple of NOS EIMAC which I will be using in my SE design<\/p>\n

\"\"<\/a>
4-65a EIMAC NOS<\/figcaption><\/figure>\n

\"\"<\/a>So did some test on distortion, transconductance and driving them to +22.22dBu output to check the quality of these two ones.<\/p>\n

I used similar test rig as before. At some point will be able to get a proper filament supply for this valve, but for the time being I will continue to use the hum pot and the big electrolytic cap across my old bench power supply which can gently provide the 3.5A for the hungry filaments!<\/p>\n

I tested them at the limit of my CCS and bench HT supply which at the moment cannot provide more than 360V @ 100mA.<\/p>\n

Transconductance is in the region of 3,800 – 4,000 \u03bcmhos.<\/p>\n

So biasing the valve at -2.5V and over 90mA of anode current, the harmonic profile looks like this:<\/p>\n

\"\"<\/a>
4-65A NOS EIMAC<\/figcaption><\/figure>\n

Both EIMAC measured about 0.12% THD.<\/p>\n

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

4-65a EIMAC NOS DHT Just got a couple of NOS EIMAC which I will be using in my SE design So did some test on distortion, transconductance and driving them to +22.22dBu output to check the quality of these two ones. I used similar test rig as before. At some point will be able to … Continue reading “4-65a EIMAC”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_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":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[12,67,24,38,5],"tags":[780,137,138,104,78,784,43,41,42,39,7],"class_list":["post-426","post","type-post","status-publish","format-standard","hentry","category-dht-valves","category-thd","category-valve-curve-tracer","category-valve-tester","category-valves","tag-4-65a","tag-4-65a-se-amplifier","tag-4-65a-thd","tag-4-65a-triode-strapped","tag-rod-coleman-regulator","tag-thd","tag-transconductance","tag-transconductance-tester","tag-tube-tester","tag-valve-tester-2","tag-valves-2"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p2r2tK-6S","jetpack_likes_enabled":true,"jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/426","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=426"}],"version-history":[{"count":5,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/426\/revisions"}],"predecessor-version":[{"id":432,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/426\/revisions\/432"}],"wp:attachment":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/media?parent=426"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/categories?post=426"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/tags?post=426"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}