{"id":7481,"date":"2018-07-20T16:59:26","date_gmt":"2018-07-20T15:59:26","guid":{"rendered":"http:\/\/www.bartola.co.uk\/valves\/?p=7481"},"modified":"2018-08-07T12:46:43","modified_gmt":"2018-08-07T11:46:43","slug":"elrog-er801a-update","status":"publish","type":"post","link":"https:\/\/www.bartola.co.uk\/valves\/2018\/07\/20\/elrog-er801a-update\/","title":{"rendered":"ELROG ER801a Update"},"content":{"rendered":"

It’s been really hectic for me over the last months. You will notice that I’ve not posted anything on this blog. Moving house and running a house renovation project whilst doing your day job is tough. Despite all this, I managed to set up a temporary lab in my new place. Yes. The system is running and I have also a workshop (or kind of).<\/p>\n

\"\"<\/a>
We have music in our temporary home!<\/figcaption><\/figure>\n

<\/p>\n

I finally received my production pair of ELROG ER801a valves<\/a>. The arrived safely and sound, however when I submitted them to the mercy of the valve curve tracer, I struggled to measure one of the valves as presented a suspicious short in grid and I suspected it has been damaged by the post service. I rarely had an issue like this, probably 2 or 3 times over more than 10 years. \u00a0Anyhow, the valves were sent back for replacement. This shows the great service you get from Thomas, not many vendors will provide this insurance as part of the product cost.<\/p>\n

Update: Thomas Mayer re-tested my valves and found that both were working fine so he just sent them back. I need to look at whether there was any socket-related issue on the e-Tracer. A bit strange as I’ve been using it for a while and only found the measurement issue consistently with this one valve. Therefore my conclusion was that it was damaged.<\/p>\n

Either way one of the valves was in perfect condition, and it measured extremely well. I wanted to share with you the curves plotted using the eTracer<\/a>, which with its latest software released has gotten better and better and is worth every single penny:<\/p>\n

\"\"<\/a>
ER801a serial D2560<\/figcaption><\/figure>\n

You can see on the image above, that it measures really well at about 102%. I will produce a Spice model from these curves when I get the chance.<\/p>\n

Here are some interesting curves using the same data set:<\/p>\n

Here are the transfer curves (anode current versus grid voltage) for a varied set of anode voltages:<\/p>\n

\"\"<\/a>
ER801a transfer curves<\/figcaption><\/figure>\n

These are useful in high-gm devices when used in a cascode topology but not for 300B. You can see the linearity of the valve at various operating points anyway with this set of curves, so they are useful anyway.<\/p>\n

Here is an interpolation of the transcoductance (gm) for various anode voltages when varying the grid voltage:<\/p>\n

\"\"<\/a>
ER801a transconductance curves<\/figcaption><\/figure>\n

You can see on the above the variance on gm for the transfer curves data.<\/p>\n

Enjoy the summer. It’s pretty hot here in London so I don’t complain at all.<\/p>\n

Cheers<\/p>\n

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

It’s been really hectic for me over the last months. You will notice that I’ve not posted anything on this blog. Moving house and running a house renovation project whilst doing your day job is tough. Despite all this, I managed to set up a temporary lab in my new place. Yes. The system is … Continue reading “ELROG ER801a Update”<\/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":[],"class_list":["post-7481","post","type-post","status-publish","format-standard","hentry","category-valves"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p2r2tK-1WF","jetpack_likes_enabled":true,"jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/7481","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=7481"}],"version-history":[{"count":3,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/7481\/revisions"}],"predecessor-version":[{"id":7509,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/7481\/revisions\/7509"}],"wp:attachment":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/media?parent=7481"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/categories?post=7481"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/tags?post=7481"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}