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#1
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Does anyone have a datasheet or tube information on a Northern
Electric R221-DX Tube? This doesn't appear in any of the usual (RCA) tube manuals. This tube appears was manufactured in Canada in the mid 1920s. Charles... |
#2
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I Googled the number and came up with a page in Japanese, which is
translated he http://translate.google.com/translate?hl=en&sl=ja&u=http://homepage.mac.com/ryomasuda/VT/num/221/index.html It's a type 201 variant. Click on the "201C" link for a chart. Dale |
#3
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Thanks. That is what I thought as they were found in an AK20 that had
one 201a in it along with these R221's. Physically the R221's are different looking than the 01a's as they have a double filament like a 071a has. The filaments also burn much redder than the 01a filaments. |
#4
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On Sun, 8 Jun 2008 12:21:03 -0700 (PDT), VA3NGC
wrote: Thanks. That is what I thought as they were found in an AK20 that had one 201a in it along with these R221's. Physically the R221's are different looking than the 01a's as they have a double filament like a 071a has. The filaments also burn much redder than the 01a filaments. If they were mine, and the AK20 was used very much, I'd swap them out for regular 201A's. I bet their 0.6A filament's life is a lot shorter than the regular .25A ones... But what do I know? ![]() Dale |
#5
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On Sun, 08 Jun 2008 16:37:50 -0700, I wrote:
... I bet their 0.6A filament's life is a lot shorter than the regular .25A ones... Err, I meant to type "0.06A". Dale |
#6
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On Jun 8, 9:48*pm, Dale Carlson wrote:
On Sun, 08 Jun 2008 16:37:50 -0700, I wrote: ... I bet their 0.6A filament's life is a lot shorter than the regular .25A ones... Err, I meant to type "0.06A". Dale Doesn't that have something to do with older tubes being 'bright emitters'? Later, thoriated tungsten cathodes were introduced that could produce sufficient electrons with lower cathode heater current? |
#7
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On Jun 14, 11:52*pm, Ron in Radio Heaven
wrote: terryS wrote: Doesn't that have something to do with older tubes being 'bright emitters'? No, bright emitters were 1 amp filament tubes. It took a good battery to run a set full of those. Ron W4RON Thanks Ron. Info appreciated. terryS |
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