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CV391

Sensibly equivalent to:
5B/252M 5B/255M LS650
See also:
Beam Tetrodes and the 807 - Brimar 25P1 Amplifier - STC 5B/254M, 5B/255M, 5B/257/M & 5B/258M Advert - STC 5B/254M, 5B/255M, 5B/257/M & 5B/258M Advert
    
Extras ▼

 

The CV391 was designed for transmitter use in the HF and low VHF parts of the spectrum. The design was an 807 in an all glass format. However, the specification quotes the prototype as the LS650.
In addition to RF power, the valves were designated for service as audio power amplifiers. Here the valve was to operate in class AB1 and a pair would deliver 15 Watts at 3% total distortion.
The specification gives the base as B8G but Loctal or B8B is the usual name.
The anode with side flanges to maximise heat dissipation from the carbonised metal.
The envelope also carries the commercial designation of 5B/255M. STC also offered the re-designed 807 as the 5B/254M, complete with anode top cap.
The wide glass tube envelope is 28 mm in diameter and, excluding the B8B base pins, is 76 mm tall.
References: 1040 & datasheet Type CV391 was first introduced in 1957.

 

Pin Connections
B8B
1
2
3
4
5
6
7
8
h
a
g2
k,bp
g1
g1
k,bp
h

 

Absolute Maximum Operating Conditions
Beam Tetrode
Vh
Ah
Va
Vs
Vg
mAa
mAs
mAg
Pdriv
Pout
Pdiss
freq
6.3
0.9
600
250
-45
100
8
4
0.3W
40W
25W
60
Thanks to Frank Philipse for supplying the above PDF datasheet.
Updated October 05, 2013.
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