Sensibly equivalent¶ to:
The ZD17 is a diode pentode valve was designed for battery portable radio receivers where the diode acts as the signal detector and the amplifier pentode is the first audio stage. This short grid base pentode was designed with particular reference to audio amplification.
The 1.4 Volt filament is to be run from a dry cell and the 90 Volt anode rating matches standard HT batteries.
Below the bright anode the open pitch of the suppressor grid can be seen.
Thanks to Mark Mallison for sending the images.
The thin glass tube envelope measures mm in diameter and the excluding the B7G base pins, is mm tall.
Reference: Data-sheet. Type ZD17 was first introduced in 1953.
Absolute Maximum Operating Conditions¶
Updated October 13, 2019.