06-10-2016, 08:54 PM
The 1e4a construction uses a helical grid around the filamentary cathode and then an external coated anode plate, so it's like a hybrid of the DM160 and DM70. I've not seen any other tube like it.
Two views of grid
Rear view (the glow is viewed through the grid!)
The Filament current is about 14mA at 1V.
The DM70 / DM71 construction is also unique:
HT Current
As well as being almost half the filament current, the HT current is a fraction of the DM70 / DM71, in practice normal operation is nearly a 1/5th.
My uTracer has difficulty with noise at such low currents!
Two views of grid
Rear view (the glow is viewed through the grid!)
The Filament current is about 14mA at 1V.
The DM70 / DM71 construction is also unique:
HT Current
As well as being almost half the filament current, the HT current is a fraction of the DM70 / DM71, in practice normal operation is nearly a 1/5th.
My uTracer has difficulty with noise at such low currents!
