The EA52 disc seal UHF diode dates from 1950. The cathode is the annular ring and the anode is the end spike.

This valve was designed for use in UHF voltmeter and monitoring devices and operate at up to 1 GHz. This exhibit shows an EA52 in such an assembly. For the valve itself See EA52. The pointed tip allows it to be used directly as the probe.

The thin glass tube envelope is 11 mm in diameter and, excluding the base pins, is 40 mm tall. The Paxolin rectangle is 34 x 25 mm and 43 mm tip to tip.

Reference: Datasheet. Type EA52 was first introduced^¶ in 1950.

 
Absolute Maximum Operating Conditions^¶

Diode	Vh	Ah	Va	mAa
	6.3	0.3	-	0.3

Thanks to Frank Philipse for supplying the above PDF datasheet

More