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AC/SG

Sensibly equivalent to:
8A1 AC/S2Pen CV1164 CV2822 HP4101C MS/Pen MSP4 SP4 SPT4A
See also:
Mazda 1929 Valve Range Advert - Mazda AC Valves advert - Mazda Brand advert - Some Important British Valves
    
Extras ▼

 

The Mazda AC/SG is and AC heated Screen Grid or tetrode amplifier for RF use. Our other AC/SG has a different construction and shows how the box screen moved to a helical grid.
The heater is the then UK standard of 4.0 Volts at 1.0 Amp. The original valves in 1929 had a metal top cap as can be seen in the advert. The screw top cap style of this exhibit is later and the top-hat top cap arrived in the mid 1930's. Thus this valve looks to date from 1932 or just after. Performance was increased in 1932 and the characteristics presented are for the enhanced version. The main change was a doubling of the AC anode resistance. A similar performance enhancement was applied to the DC/SG that first appeared in 1931.
See also the metalised AC/SG.
The electrodes side view. The anode consists of a small plate placed either side of the screen.
The screen consists of the lower metal cup and a substantial rectangular cage with close spaced grid wires.
The getter holder is on the left. The pressed ridges to give structural rigidity to the anode are clearly seen.
The balloon envelope is 45 mm in diameter, and excluding the B5 base pins is 115 mm tall.
References: 1040 & 1043. Type AC/SG was first introduced in 1929.

 

Pin Connections
B5
1
2
3
4
5
tc
g2
g1
h
h
k
a

 

Absolute Maximum Operating Conditions
Tetrode
Vh
Ah
Va
Vs
Vg
mAa
mAs
ra
gm
4.0
1.0
200
60
-1.5
4.5
0.8
0.9M
1.9
Updated August 05, 2015.
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