▼ Menu

AC/Pen

Sensibly equivalent to:
7A2 A70B APP4A CV1174 KT42 MKT4/5 MKT4/7 MP/Pen N40 Pen4VA
See also:
Some Important British Valves - CV1174 short entry
    
Extras ▼

 

Mazda introduced the AC/Pen in 1930 and it was the first technically successful indirectly-heated power pentode capable of enough output to drive a moving-coil loudspeaker at good volume. Here we have an AC/Pen made by Arctron. It must date to 1933 or later as it has the B7 base cap.
The AC/PEN and 250V cab be read but the Arctron name is very feint.
Looking up into the envelope the anode can be seen to have a cylindrical working cavity and four flanges. The inner coating on the glass makes this difficult to see.
An Arctron box courtesy of G3YNH, as seen on his website.
The classic envelope is 58 mm in diameter and excluding the B5 base pins, is 112 mm tall.
References: Datasheet & 1043. Type AC/Pen was first introduced in 1930.

 

Pin Connections
B7
1
2
3
4
5
6
7
-
g1
g2
h
h
k,g3
a

 

Absolute Maximum Operating Conditions
Pentode
Vh
Ah
Va
Vs
Vg
mAa
mAs
ra
gm
Pout
D
4.0
1.0
250
250
-15.5
32
6
75k
2.7
3.3W
7%
Thanks to Frank Philipse for supplying the above PDF datasheet.
Updated April 07, 2015.
Return to Main Index