▼ Menu

41STH

Sensibly equivalent to:
20A1 A36A AC/TH1 CV2508 TH4 X41M
    
Extras ▼

 

The 41-STH is a triode hexode frequency changer. The triode is employed as the local oscillator and the hexode as the mixer. The input RF signal is coupled to the hexode control grid via the top cap for maximum separation of the oscillator and mixer.
This frequency-changer is a very well-designed valve capable of stable operation up to at least 30 MHz.
Unlike our other 41-STH this example has the top cap present, but lacks the original identification which was probably a paper label.
The reverse is plain zinc paint. Note the wire from the base to the screening paint.
The classic envelope is 44 mm in diameter and, excluding the B7 base pins, is 113 mm tall.
References: 1043 & 1040. Type 41STH 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
ra
gm
4.0
1.15
250
100
-1.5
3.0
4.0
1.6
0.6

 

Absolute Maximum Operating Conditions
Triode
Va
mAa
80
4.5
Updated January 09, 2017.
Return to Main Index