▼ Menu

7D3

Sensibly equivalent to:
40PPA
See also:
Ten Times Tested Valves Advert
    
Extras ▼

 

The 7D3 is an audio output pentode that was designed for single ended use in universal sets. The heater is designed for series connection across the mains supply, and the anode ratings reflect the low HT available when no mains transformer is available.
The 25A6G is the same valve electrically but with a 300 mA heater and an IO base cap.
The Brimar identification on the base cap.
The classic envelope is 44 mm in diameter, and excluding the B7 base pins is 95 mm tall.
References: Data-sheet & 1040. Type 7D3 was first introduced in 1935.

 

Pin Connections
B7
1
2
3
4
5
6
7
8
m
h
a
g2
g1
-
h
k

 

Absolute Maximum Operating Conditions
Pentode
Vh
Ah
Va
Vs
Vg
mAa
mAs
ra
gm
Pout
D
40
0.2
160
120
-18
36
12
42,000
2.4
2.2
10%
Thanks to Frank Philipse for supplying the above PDF datasheet.
Updated August 03, 2020.
shape:classic construction:pinch type:pentode age:1930.1940 base:b7 heater:200ma pins:8 pin:1.m pin:2.h pin:3.a pin:4.g2 pin:5.g1 pin:6.- pin:7.h pin:8.k
Return to Main Index