PX25 Osram {probably the first batch} enraged logo on glass large anode V shaped base P27/500 CV1040 PP5/400 equivalent

Description

AudioMagical introduces most of all PX25 type made from 1932 up to the 1960s

The PX25 is a output valve like a PX4 but with higher output and Anode Voltage.

Pair of early 1930s Osram, PX25 with logo etced on glass

We believe these are the earliest PX25 balloon ever made!

The PX25 type can be seen and read on top envelope.

Anode is stirdy with 4 tension spirngs

The Osram PX25 is a power amplifying valve of extremely high efficiency designed with a large power handling capacity to supply considerable undistorted volume. 

For use in the last stage of Low Frequency Amplifiers where provision is made for adequate high tension supply. When operating the PX25 valve, arrangement should be made for sufficient air circulation to prevent over-heating

Filament Voltage 4

Filament Current 2 amps 

Anode Volts 400

Grid Volts -31

Anode Current Average 62

Anode Dissipation 25 Watts

Mutual Conductance  mA/V 8

 

Tested with AVO VCM 163

Osram PX25  {1} 47mA 100% emission mA/V 7

Osram PX25  {2} 46mA 100% emission mA/V 7

Supplied with provisional boxes