CV1574

CV1574 / CV1699 / CV1700 HF pentode.

The valve measures 95x33mm overall and has a Mazda Octal base

Although listed as separate CV numbers, each of these valves also carries the SP41 label. The only clues as to any difference are in the fact that the CV1699 is also known as PO VT150, and the CV1700 as PO VT150A, both being to GPO specifications. The CV1574, as indicated on the box of the VR65A pictured below, is shown on the EVS data sheet as VR65A.

Heater voltage	4V
Heater current	0.95A
Max anode voltage	250V
Max screen voltage	250V
Max anode dissipation	4.5W
Max screen dissipation	1.25W
Mutual conductance	8.5mA/V
Max operating frequency	60MHz

Pin	Function
1	Heater
2	Cathode
3	Anode
4	Screen grid
5	Suppressor grid
6	Metallising
7	No pin
8	Heater
TC	Control grid

VR65A CV1574 box
The VR65A's box marked CV1574. The label says "The Pattern Number shewn on this slip is the new designation of the Valve enclosed. Supplies should be taken on charge, and demanded under the new Pattern Number in future. S.N.S.O. Haslemere, December, 1943."

VR65A

SP41

	CV1574, left, but this example has no metallising.

STC CV1699 above and SP41 markings on the rear, below.	STC CV1700 above and SP41 markings on the rear, below

Virtual Valve Museum