This is a double beam-power tube with a 1 + 6 pin septar base and two pins for the plate extending out the top of the envelope. One pin is larger than the others to provide the pin-one orientation. This is a spare tube for Register Driver S/N 6.
Manufacturer
National Union
Place Manufactured
U. S.
Identifying Numbers
Model number
3E29
Printed in white ink around glass envelope.
Other number
E-220
Handwritten in silver ink around glass envelope.
Other number
OMD3V9-2
Handwritten in yellow ink vertically on glass envelope.