▼ Menu

TH4A

 
See also:
Tungsram HL2 Box
    
Extras ▼

 

The TH4A is an indirectly heated triode hexode frequency changer with the 1930's standard 4.0 V heater. The box it came in matches the HL2 box referenced to above.
The triode is employed as the local oscillator and the hexode for the mixing process, the input signal being coupled to the control grid via the top cap for maximum separation of the circuits.
The classic envelope is 45 mm in diameter and, excluding the B7 base pins, is 126 mm tall.
References: Datasheet & 1043. Type TH4A was first introduced in 1938.

 

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
4.0
1.5
250
100
-2
3.5
5.5
0.85

 

Absolute Maximum Operating Conditions
Triode
Va
mAa
100
1.5
Thanks to Frank Philipse for supplying the above PDF datasheet.
Updated January 07, 2013.
Return to Main Index