Triotron Austria P440N APP4100 L4150D RENS1374 Mesh Pl. Triode Radio Vacuum Tube
P440N ~ RENS1374d ~ E453 ~ L4150D ~ APP4100 ~ 1374d. Triotron P440N Output Pentode – Rare Austrian RENS1374d Equivalent. Triotron P440N Output Pentode – Rare Austrian made. Tube Type: P440N – Indirectly-Heated Output Pentode.
Triotron Holland HF93 NOS Tube Röhre Valvola Lampe
NOS is subject to interpretation and there is no specific definition for it either. There are suggestions and opinions. Tube testers do not test for these problems in the manner in which you think, except to the extent that a tube tester with sensitive leakage detection will find far more “noisy” tubes than a tube tester with only “fair” leakage sensitivity, to the extent that the noise is due to this problem.
