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Z77

Sensibly equivalent to:
6AM6 6F12 8D3 CV138 CV4014 EF91 HP6
See also:
EF91 - not the valve that won the war - Television RF Valve Development - Valves and their Habits - Valves for Bands III, IV & V - The EF91 and the Blue Band
    
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The Z77 from M-OV was another designation for the ubiquitous EF91 of the late 1940s and early 1950s.
The design offers high gain, high impedance, high slope, in a screened pentode.
The electrodes fill the width of the valve. The three grids can be clearly seen and all grids have separate pins.
See also Z77 for a Marconiphone branded valve.
The thin glass tube envelope is 18 mm in diameter and, excluding the B7G base pins, is 46 mm tall.
References: Datasheet & 1040 Type Z77 was first introduced in 1947.

 

Pin Connections
B7G
1
2
3
4
5
6
7
g1
k
h
h
a
g3
g2

 

Absolute Maximum Operating Conditions
Pentode
Vh
Ah
Va
Vs
Vg
mAa
mAs
ra
gm
6.3
0.3
250
250
-2
10
2.5
1M
7.6
Thanks to Frank Philipse for supplying the above PDF datasheet.
Updated April 01, 2014.
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