The AC/VP1 is a variable μ screened pentode designed for mains radio receivers. The variable μ characteristic enables automatic gain control of RF and IF amplifiers in superhet receivers.

The AC/VP1 and AC/VP2 were the standard RF/IF screened pentodes in the Mazda range for AC mains radios from the mid-1930s until domestic radio manufacture was interrupted by WW2.

The two valve types were essentially identical except that the AC/VP1 has its anode connected to the top cap, as with most screen-grid valves. The AC/VP2 has the control grid (g1) connected to the top cap, as was standard for later IF pentodes.

The classic envelope is 38 mm in diameter and, excluding the B7 base pins, is 103 mm tall.

 
Pin Connections

B7	1	2	3	4	5	6	7
	m	g1	g3	h	h	k	g2

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm
	4.0	0.65	250	250	-2.8	7.4	1.85	1M	2.0

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 05 July 2007 {find valves by name}