The UCH81 is a triode oscillator and heptode mixer for use as a frequency changer in superhet receivers.
The 100 mA heater is designed for universal mains sets, and this is why the anode voltage is 200 maximum.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 58 mm tall.
Pin Connections
B9A |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |

|
g2,g4 |
g1 |
k,g5,s |
h |
h |
a(h) |
g3 |
a(t) |
g1(t) |
Absolute Maximum Operating Conditions
Heptode |
Vh |
Ah |
Va |
Vs |
Vg |
mAa |
mAs |
ra |
gm |

|
19.0 |
0.1 |
200 |
119 |
-2.6 |
3.7 |
8.1 |
1.0M |
0.78 |
|