The CV1526 is an interesting CRT from several perspectives, firstly it is relatively long for the screen diameter, secondly there is a fourth anode acting after the deflection plates and PDA (post deflection acceleration) is normally seen on later tubes and finally the pinch ends in a pressed glass foot.

These features seem to point to an early high frequency display. The length allows for a small deflection angle and thus requires a low deflection voltage. Developing a high voltage at wide bandwidth requires special amplifier valves and we may conclude that these were not available. The 4.0 V heater was common on UK valves in the 1930s but not the 1940s. The glass foot also suggests mid to late 1940s and conflicts with a 4.0 V heater.

The PDA a4 has connects to the envelope via a side contact as would be found on television tubes.

The connection to the fourth anode.

The identification label, deflection plates and electrodes assembled on ceramic rods.

The Pinch is interesting in that it ends with a pressed glass foot rather than the traditional pinch.

The gun assembly.

The screen is domed as laminated glass faceplates to allow flat screens had not been developed. The domed screen puts the glass in compression and the tube is less likely to fail due to implosion of the screen.

The end window envelope is 40 mm in diameter, and excluding the base pins is 230 mm tall. The screen has a maximum diameter of 68 mm.

 
Pin Connections

	1	2	3	4	5	6	7	8	9	10	11	12	tc
	k	g1	h	h	a2	-	Y2	X2	a1,a3	X1	Y1	-	a4

 
Absolute Maximum Operating Conditions

CRT	Vh	Ah	Va
	4.0	1.0	3,000

This exhibit was last updated on 07 May 2009