easyone Posted January 10, 2018 Share Posted January 10, 2018 Hello all, I am starting to go through all my tubes and would like to get better at identifying tubes more specifically. Things like plate and getter types. As an example I am looking at 2 RCA 12ax7 tubes and do not know much more than that. Could someone please help me understand a few of the things that are identifiable with my eyes - and a magnifying glass. As far as the getter types - am I supposed to look at the plate on top? If so, it can be difficult to see them because of the grey frosted glass in the tops of the tubes. I will post a few pics and hopefully the pics show enough info for a quick lesson. Any info would be greatly appreciated! The tubes look to have black plates. The camera flash or open aperture makes some of the pics look like the plates are grey. Quote Link to comment Share on other sites More sharing options...
jimjimbo Posted January 10, 2018 Share Posted January 10, 2018 Hopefully this will help to some degree. Google is your friend...... Quote Link to comment Share on other sites More sharing options...
jimjimbo Posted January 10, 2018 Share Posted January 10, 2018 Quote Link to comment Share on other sites More sharing options...
easyone Posted January 10, 2018 Author Share Posted January 10, 2018 Thanks for the diagrams they are helpful. I am still wondering about specifics like - Is the tube a long or short plate? Is the plate ribbed? What type of getter might the tube have? Quote Link to comment Share on other sites More sharing options...
joshnich Posted January 10, 2018 Share Posted January 10, 2018 I would say its a ribbed long plate with a square getter. I have a number of RCA 12AX7 's that have a short plate and a halo getter. I dont know enough about them to know when either of those were made or if one is considered better than the other! Quote Link to comment Share on other sites More sharing options...
easyone Posted January 10, 2018 Author Share Posted January 10, 2018 1 hour ago, joshnich said: I would say its a ribbed long plate with a square getter. I have a number of RCA 12AX7 's that have a short plate and a halo getter. I dont know enough about them to know when either of those were made or if one is considered better than the other! Thanks for the input. I would guess long plate also based on pictures I found on tube seller websites, but I do not know for a fact they are long plate. Quote Link to comment Share on other sites More sharing options...
edmjm Posted January 30, 2018 Share Posted January 30, 2018 definitely long, ribbed plate Quote Link to comment Share on other sites More sharing options...
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