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The Dawn of Broadcasting in the UK
collections The John Lawrence Collection |
The DE4 is a rare valve, little used and not generally included in contemporary lists. Some collectors even doubt that the DE4 existed, but we know of at least two.
We believe that this sample dates from 1925, based on the style of markings and the base. Earlier versions had a metal shell base cap.
This triode is rated at 3.8 volts filament voltage. This suggests accumulator supplies of 4 Volts nominal. The base is British four pin and the valve is marked with the BBC stamp.
The balloon envelope is 59 mm in diameter and, excluding the B4 base pins, is 105 mm tall.
This exhibit was last updated on 02 December 2007
We believe that this sample dates from 1925, based on the style of markings and the base. Earlier versions had a metal shell base cap.
This triode is rated at 3.8 volts filament voltage. This suggests accumulator supplies of 4 Volts nominal. The base is British four pin and the valve is marked with the BBC stamp.
The balloon envelope is 59 mm in diameter and, excluding the B4 base pins, is 105 mm tall.
This exhibit was last updated on 02 December 2007
The balloon envelope is 59 mm in diameter and, excluding the B4 base pins, is 105 mm tall.
This exhibit was last updated on 02 December 2007
This exhibit was last updated on 02 December 2007 |