Sensibly equivalent¶ to:
The DM70 is a miniature tuning indicator designed for dry battery operation. This exhibit was made in Holland by Philips.
The DM70 introduced in 1952 was one of the first miniature devices produced by Mullard.
The display changes from minimum to maximum for a 10 Volt change on the control grid. The discharge channel is tapered and the glowing column will travel further along as the voltage is altered. See DM70 for a diagram.
Thanks to John Sykes for sending the photographs.
The thin glass tube envelope is 9 mm in diameter and, excluding the B8D base pins is 43 mm tall.
References: Datasheet & 1040. Type DM70 was first introduced in 1952.
Absolute Maximum Operating Conditions¶
Updated December08, 2015. shape:thin.glass.tube construction:all.glass type:tuning.indicator age:1950.1960 base:b8d heater:1.4v pins:8 pin:1.g1 pin:2.ic pin:3.- pin:4.f pin:5.f pin:6.- pin:7.- pin:8.a