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ECH84

Sensibly equivalent to:
6JX8
See also:
National Radio Show 1961 - ECH84 Advert - ECH84 - PCL86 & ECH84 Advert
    
Extras ▼

 

The ECH84 is a low voltage triode heptode. The ECH84 was specifically designed for operation as a sync separator in negative-modulation television receivers, the dual control feature of the heptode allowing the suppression of noise that would otherwise cause sync errors.
The ECH84 replaces the ECH81 for television systems. The ECH81 was never designed for more than AM broadcast receivers whereas the ECH84 is purpose designed for TV receivers.
The triode heptode could be also used as a frequency changer for medium and long wave radio receivers. The heptode has a straight characteristic that makes it suited as AM modulator.
See also the car radio frequency changer ECH83.
The thin glass tube envelope is 20 mm in diameter, and excluding the B9A base pins, is 56 mm tall.
References: Data-sheet & 1040. Type ECH84 was first introduced in 1961. See also 1961 adverts.

 

Pin Connections
B9A
1
2
3
4
5
6
7
8
9
g3
g1
k,g5,s
h
h
a
g2,g4
a(t)
g1(t)

 

Absolute Maximum Operating Conditions
Heptode
Vh
Ah
Va
Vs
Vg
mAa
mAs
gm
6.3
0.3
135
14
0
1.7
0.9
2.2

 

Absolute Maximum Operating Conditions
Triode
Va
Vg
mAa
ra
gm
50
0
3.0
13.5k
3.7
Thanks to Frank Philipse for supplying the above PDF datasheet.
Updated September 07, 2016.
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