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TH21C

Sensibly equivalent to:
202STH
    
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The TH21C is an indirectly heated triode hexode frequency changer (mixer) designed for universal sets without a mains transformer. The 200 mA heater is designed for series connection as part of a heater chain and has a warm-up time of 30 seconds. For AC mains only sets, with a mains transformer, the TH4 is electrically identical to the TH21C apart from the heater rating.
The envelope is fully coated with metal loaded screening paint and no marks are present on the reverse.
The classic envelope is 49 mm in diameter, and excluding the B7 base pins is 126 mm tall.
References: Datasheet& 1043. Type TH21C was first introduced in 1936.

 

Pin Connections
B7
1
2
3
4
5
6
7
tc
a(t)
g1(t),g3
g2,g4
h
h
M,k
a
g1

 

Absolute Maximum Operating Conditions
Hexode
Vh
Ah
Va
Vs
Vg
mAa
mAs
gm
ra
gm
21.0
0.2
250
70
-1.5
4.0
6.0
0.6
1.5M
1.0

 

Absolute Maximum Operating Conditions
Triode
Va
mAa
130
6.0
Thanks to Frank Philipse for supplying the above PDF datasheet.
Updated August 26, 2018.
shape:classic construction:pinch type:triode.hexode age:1930.1940 base:b7 heater:200ma pins:7 pin:1.a(t) pin:2.g1(t).g3 pin:3.g2.g4 pin:4.h pin:5.h pin:6.m.k pin:7.a pin:tc.g1
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