FULL WAVE RECTIFIER
The 6X4WA Vacuum tube is a miniature type used in the
power supply of automobile and
ac-operated radio receivers. It requires a miniature
7-contact socket and may be mounted in any position. It is
especially important that this tube, like other
power-handling tubes, should be kept cool and adequately
ventilated.
Electrical Data:
Heater Voltage ................................ 6.3 V
Heater Current ................................ 0.36 A
Maximum Heater-Cathode Voltage Heater Positive with
Respect to Cathode DC Component ................... 450 V
Heater Negative with Respect to Cathode:
DC Component ................. 450 V
Preferred Substitutes ......................... 6BX4
Substitutes ............................. 6202, 6AV4, 6X4WA
Having worked for several companies who made or supplied items for the
government, I can say the testing and documentation required for even the
smallest item probably has a big effect on the markup.
In most cases a WA tube won't be noticable from an A - unless it is running under
very severe conditions. When the possibility of a tube failing can put a soldier
or platoon in danger, when something MUST be able to perform above and beyond the
call of duty, the added ruggedness of a W tube could make the difference. Someone
in the middle of the jungle won't care if the tube was cheap - but they WILL care
a great deal if it doesn't work.
But if that radio is just going to sit in your living room and play, and the
worst case scenario of that tube failing is that the radio stops playing...that
tube is cheaper to sell.