3X2500A3  8161

The 3X2500A3 or 8161 is a 2500 watt triode with a mu of 20 and a maximum frequency for full output of 75 MHz. Forced air is required. The tube was first offered for sale in late 1945 and I beleive the first example is one of these early tubes. The anode isn't plated and is soldered to the cooling fins. The black painted dome of the anode is also larger than later tubes. The second example is a newer version and has the more efficient anode construction. As shown in the third example, some tubes of this type were equipped with a special industrial filament connection.

Length = 8.60" Diameter = 4.16"
Max voltage = 6000
Max current = 2.5 amps
Fil voltage = 7.5
Fil current = 49 to 54 amps
Data sheet:

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