| Neuberger RPM370 Tube Tester | |||||||||
) |
This is the best tube tester that was made in Germany in the 1950s. Due to some special features they still work great: - no electrolytic caps - only MP types are used - tube rectification with 3 RGN 1064 tubes of SQ - great quality overall (as Rohde + Schwarz) My tester is from 1956 and still works perfectly. The later model RPM 375 received some changes. The most significant are the rectangular meters. The RPM 370 works from 0-500 Volts for plates and screens (the Funke tube testers do not) and from 0-100 for grid bias. All tests are made to the original design specifications: no "good" or "bad" tube - only absolute and comparable results. Before testing a tube's emission all electrodes are tested for infinite resistance. Then the gas can be tested as well as transconductance a.s.o. |
||||||||
) |
|||||||||
|
|
How to improve
performance: 1. I use two separate digital volt meters to control bias and plate voltage when measuring 2. Parallel the grids when testing double triodes (as ECCs). This allows lower test deviation. 3. Connect a speaker (through a small transformer) in series to the plate current. This enables you to listen if the tube is free from microphonics or cathode defects. |
||||||||
) |
|||||||||
) |
) |
||||||||
) |
|
||||||||
) |
|
||||||||
|
|
|||||||||
 |
|
|
|
||||||
)
)
