The UR1C is a half wave rectifier designed for 200 mA series connected heaters as found in AC/DC radio receivers. The anode voltage is the RMS value and the maximum heater to cathode voltage is 350 Volts.

The reservoir capacitor can be 16 µF with an effective minimum series resistance of 75 Ohms. For a 32µF capacitor the series resistance must be a minimum of 125 Ohms. The heating time is quoted as 70 seconds, this gives time for all of the valves to heat-up before HT is applied.

The literature gives the UR1C as an equivalent to the 1D5, and most respects it is, but the ID5 has a 40 Volt heater at 200 mA.

The classic envelope is 38 mm in diameter and, excluding the B5 base pins, is 100 mm tall.

 
Pin Connections

B5	1	2	3	4	5
	a	-	h	h	k

 
Absolute Maximum Operating Conditions

Rectifier	Vh	Ah	Va	mAa
	20.0	0.2	250	75

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 12 June 2007 {find valves by name}