Band 1 Channel 1 Rod Pentode modulator

[Mike Watterson]

Thank you. What do you think about the modulator lifetime? Russian pentodes are not very durable.

Not true.

The types for proximity fuzes are not durable when run at full power. They are all very durable in normal applications. Note the rated filament is 1.2V. Compare with Dx96 series B7G that are 1.4V nominal (not 1.5V) that are recommended to be run at 1.35V by Philips when not on batteries, which have a 1V end point.
So comparable is to run at 1.1V, at that rating and with NORMAL Cathode current, the life probably exceeds the DF96 and similar.
Note that the battery packs were NiCd, not NiMH, which is a bit higher voltage. Also Lead Acid valves were never meant to be connected while the cell(s) are on charge. The NiMH terminal voltage rises to 1.5V on charge. The Philips (Mullard) 1.4. types on continental sets were run up to 1.4V when the NiCd (DEAC) was charged on Mains operation. I don't know if the Russians swapped battery packs to charge, but likely they did.

They were used in Manpacks, terrestrial vehicles, MiG fighters and satellites. Only those in shells, bombs and missiles had a short operational life.