The 20P3 is an audio output valve designed for single end use in universal mains receivers. The 200 mA heater indicates a cross over between radio and television equipment. The probability is that 200 mA heater chains were to be found in small VHF monochrome television sets.

The Mazda valve was designed after the time when Mazda gave up their own version of the octal base and adopted the standard.

The cathode resistor was designed to be 180 Ohm and the anode load to be 3700 Ohms.

We have the 10P14 in the museum and it has identical operating characteristics and pin connections and was designed for a 100 mA heater chain.

The wide glass tube envelope is 28 mm in diameter, and excluding the IO base pins, is 54 mm tall.

 
Pin Connections

IO	1	2	3	4	5	6	7	8
	m	h	a	g2	g1	-	h	k

 
Absolute Maximum Operating Conditions

Beam Tetrode	Vh	Ah	Va	Vs	Vg	mAa	mAs	gm	Pout	D
	20.0	0.2	195	210	-11.5	51.0	12.7	7.4	4.5W	7%

This exhibit was last updated on 03 March 2005