lausmobile Tube Tester Files
Reflector 02/1989, typical sample of four tested. This tube has probably the smallest plate assembly for the mini-9 package tube - about 2mm total width! Compare it to stock 12AX7. This tube is intended for oscillator / heterodyne use, seldom used for audio amplification (Yuri Makarov's phono stage is one known to me). It loves oscillating indeed, and it took a 47 kOhm grid-cathode shunt to quiet it down.
| Standard specifications per each triode | |||
| Parameter | Maximum | Operating Point | Measured (*) |
| Ua, V | 300 | 150 | 140 |
| Ug, V | - | -2.0 | -2.0 |
| Ia, mA | 18 | 7.5 | 7.0 |
| Pa, W | 1.5 | (1.1) | (1.0) |
| Gm, mA/V | - | 5.9 | 4.8 |
| Rp, kOhm | - | (6.25) | 6.5 |
| Mu, V/V | - | 36 | 31 |
1. Full power curve - 6.3V heater. Disregard color coding - 47k resistor disabled grid current tracking.
2. 10 mA closeup
3. 10mA closeup, curves at 5.0V heater superimposed on the above chart
4. Gm / Mu / Rp
Legend: White curves: Ig<5uA Yellow: 5<Ig<20uA Red: 20<Ig<300uA. Measurements terminate at Ig>300uA
English Home - Russian Home - English Tube List - Russian Tube List - Mail (c) klausmobile 2001
