{"id":1017,"date":"2013-01-06T18:30:47","date_gmt":"2013-01-06T18:30:47","guid":{"rendered":"http:\/\/www.bartola.co.uk\/valves\/?p=1017"},"modified":"2013-01-06T18:30:47","modified_gmt":"2013-01-06T18:30:47","slug":"4p1l-pentode-spice-model","status":"publish","type":"post","link":"https:\/\/www.bartola.co.uk\/valves\/2013\/01\/06\/4p1l-pentode-spice-model\/","title":{"rendered":"4P1L Pentode Spice Model"},"content":{"rendered":"

Inspired by Rajko’s model<\/a>, I tried creating my own Spice model of the 4P1L pentode:<\/p>\n

\"4P1L<\/a>Dmitry’s tool for pentode is difficult to fit to the pentode curves, not as the triode tool which is very accurate. Here’s Dmitry’s explanation:<\/p>\n

“The pentode model equations, as defined by Koren, have one very, very important property: they reduce to a pretty accurate triode model of the same device if the screen moves together with the plate (I have a parameter UL for that and for ultra-linear arrangement, UL=1 is triode – try it! – then ul=0.4 or so is for UL connection, UL>1 is so called supertriode connection). That’s the good news, a really good one but that is the end of the good news. The bad news is that pentode and tetrode fitting can be at best very approximate – that is, the knee region and the slopes are not right for most tetrodes and pentodes, with the exception for some small-signal pentodes.”<\/p>\n

Here is my model. Hopefully someone can try it and report some results:<\/p>\n

** 4P1L PENTODE ************************************************************
\n* Created on Sun Jan 06 18:21:28 GMT 2013 using tube.model.finder.PaintKIP
\n* model URL:
\n*————————————————–
\n.SUBCKT PENT_4P1L PENTODE 1 2 3 4 ; P G K G2
\n+ PARAMS: CCG=9P CGP=0.1P CCP=9.5P RGI=2000
\n+ MU=9.27 EX=1.4139 KG1=1658.84 KG2=3528.0 KP=469.2 KVB=40.504 ; Vp_MAX=450.0 Ip_MAX=0.07 Vg_step=1.0
\n*————————————————–
\nRE1 7 0 1MEG ; DUMMY SO NODE 7 HAS 2 CONNECTIONS
\nE1 7 0 VALUE= ; E1 BREAKS UP LONG EQUATION FOR G1.
\n+{V(4,3)\/KP*LOG(1+EXP((1\/MU+V(2,3)\/V(4,3))*KP))}
\nG1 1 3 VALUE={(PWR(V(7),EX)+PWRS(V(7),EX))\/KG1*ATAN(V(1,3)\/KVB)}
\nG2 4 3 VALUE={(EXP(EX*(LOG((V(4,3)\/MU)+V(2,3)))))\/KG2}
\nRCP 1 3 1G ; FOR CONVERGENCE
\nC1 2 3 {CCG} ; CATHODE-GRID 1
\nC2 1 2 {CPG1} ; GRID 1-PLATE
\nC3 1 3 {CCP} ; CATHODE-PLATE
\nR1 2 5 {RGI} ; FOR GRID CURRENT
\nD3 5 3 DX ; FOR GRID CURRENT
\n.MODEL DX D(IS=1N RS=1 CJO=10PF TT=1N)
\n.ENDS<\/p>\n","protected":false},"excerpt":{"rendered":"

Inspired by Rajko’s model, I tried creating my own Spice model of the 4P1L pentode: Dmitry’s tool for pentode is difficult to fit to the pentode curves, not as the triode tool which is very accurate. Here’s Dmitry’s explanation: “The pentode model equations, as defined by Koren, have one very, very important property: they reduce … Continue reading “4P1L Pentode Spice Model”<\/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":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[12,24,5],"tags":[782,285,284,288],"class_list":["post-1017","post","type-post","status-publish","format-standard","hentry","category-dht-valves","category-valve-curve-tracer","category-valves","tag-4p1l","tag-4p1l-pentode","tag-4p1l-pentode-curves","tag-4p1l-pentode-spice-model"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p2r2tK-gp","jetpack_likes_enabled":true,"jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/1017","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=1017"}],"version-history":[{"count":2,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/1017\/revisions"}],"predecessor-version":[{"id":1020,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/1017\/revisions\/1020"}],"wp:attachment":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/media?parent=1017"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/categories?post=1017"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/tags?post=1017"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}