20-06-2020, 08:13 PM
(This post was last modified: 20-06-2020, 08:14 PM by Mike Watterson.)
No, the MO is altogether larger.
So you must have one built just after the factories in London were Blitzed, which was in 1941. A very rare early all octal. Presumably the models with mixes of P8 and Octal were using up odd stocks of P8 valves. Most of those where Comfort sets.
Almost all the octal 1.4V battery valves during the war were US imports. UK production was on types for the war effort.
International Octal (Created by RCA)
A 17.45 mm (11⁄16 in) diameter circle around a 7.82 mm (5⁄16 in) diameter keyed post. The heater pins usually 2 and 7.
Mazda Octal
The heater pins are usually 1 & 8. The heater pins are 55.5 apart and the other pins 43.5 apart. Not sure what units. I can see on my valve tester the MO socket has obviously wider spaced pin 1 and 8, about 10mm. Diameter of circle about 20mm, the IO socket measured with same steel rule from above looks like 18 mm (actually 17.45). Many were initially the 4V 7 pin just with the new Mazda base.
It was short lived and battery sets that used them switched to regular Octal during the war.
So you must have one built just after the factories in London were Blitzed, which was in 1941. A very rare early all octal. Presumably the models with mixes of P8 and Octal were using up odd stocks of P8 valves. Most of those where Comfort sets.
Almost all the octal 1.4V battery valves during the war were US imports. UK production was on types for the war effort.
International Octal (Created by RCA)
A 17.45 mm (11⁄16 in) diameter circle around a 7.82 mm (5⁄16 in) diameter keyed post. The heater pins usually 2 and 7.
Mazda Octal
The heater pins are usually 1 & 8. The heater pins are 55.5 apart and the other pins 43.5 apart. Not sure what units. I can see on my valve tester the MO socket has obviously wider spaced pin 1 and 8, about 10mm. Diameter of circle about 20mm, the IO socket measured with same steel rule from above looks like 18 mm (actually 17.45). Many were initially the 4V 7 pin just with the new Mazda base.
It was short lived and battery sets that used them switched to regular Octal during the war.
