This NR4C has lost its base, but the electrodes are still clearly seen within the envelope. The filament is a single strand running through the centre of the anode cylinder. Between the 9 mm diameter anode and the filament is a thick wire helical grid 3mm in diameter.
The NR prefix indicates that it was made for the British Navy as a receiving valve. The number 4 indicates that this was a very early device used by the Navy.
The balloon envelope is 48 mm in diameter and, 66 mm tall.
This exhibit was last updated on 19 January 2003
The NR prefix indicates that it was made for the British Navy as a receiving valve. The number 4 indicates that this was a very early device used by the Navy.
The balloon envelope is 48 mm in diameter and, 66 mm tall.
This exhibit was last updated on 19 January 2003
This exhibit was last updated on 19 January 2003
This exhibit was last updated on 19 January 2003 |