1920s deForest D-01A radio audion tube, near pristine graphics, TESTS STRONG

Description

In the mid 1920s the deForest company introduced it’s unique version of the 5V battery radio tube to be a direct equivalent of the UX 201A tube.
The deForest D-01A audion tube was a beautiful looking tube with a glass tip, paper label giving spec and type number.
It also was unique in having a bright white “isolantite” base (a form of ceramic) which contained stamped, printed information with the deForest signature.
This version of the tube was short lived and was later replaced by the D-401A tube
This is a near pristine looking example of this D-01A tube.
The glass tip is good, the base is tight with no rattles,  the paper label and printing are in wonderful condition.
The filament tests good at 3.4 ohms. The tube was tested on a Dan Nelson calibrated TV7 tester where minimum is 18.  Tube tested at 30 as shown in photo