Chart below is an Eg - Ip characteristic of Osuram PX-25.
Aiming at this measurement, I produce it with a parts of my junk box.
大型三極管の特性を測定したい Starting February 18 2005
Measure a characteristic of a large-sized triode tubes.
Wants to measure Osram PX-25 and RCA 211, good or bad check and characteristic. But cannot measure it in my I-177 tube checker. Therefore I wanted to make a simple measurement device. A device measuring Transconducatance(gm) is complicated. Only an Eg-Ip characteristic needs the measurement. |
Making transformer for bias 2005-3-27 almost assembling completed 2005-3-27 Circuit 3-29 Similation of the measurement and Graph drawing |
Chart below is an Eg - Ip characteristic of Osuram PX-25.
Aiming at this measurement, I produce it with a parts of my junk box.
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211A Kawanisi Tube Japan. ＶＴ104 10E/215 U.K. ＰＸ-25 Osram U.K. 2E22 Tung-Sol U.S.A. |
The parts, I selected and prepared.
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A chasis for old radios seeming to be four ordinary radio useed. which Called "Nami 4 Radio” in Japan. |
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The old power transformer which was used for five tubes radio. |
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B winding is 350V, 70mA. The grade is good for five tubes radio because used vacuum tube 42 and 80. However, this is old |
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The used meter which took out from a junk box On the back , there was indication with iron panel use |
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Vari tap of using Triac for B voltage controler. Inserted in the primary of a transformer. |
Roughly temporary assembling February 23 2005.
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A chasis and a transformer painted it with lacquer of having whatever is
available. Going to block up an unnecessary hole. |
| The board which blocks up an unnecessary hole of a chasis. and put a some parts on this board February 25 |
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Temporary assembling February 27
A vacuum tube inserting is Osram PX-25.
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A jumbo socket of 211 is going to install on the board, left side of the transformer. |
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 A jumbo socket for RCA 21１ |
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