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Information - Help 
ID = 11018
Great Britain (UK)
Brand: Common type Great Britain tube/semicond.
Tube type:  Beam Power Tube   beam power   Power/Output 
Identical to CV73 = V1120B = 11E3 = 5B/103B
Similar Tubes
Heater different:
Other base and other heater:

Base British-7-Pin, old (M7A) (Codex=Ncb) Top contact with a cap.
Was used by Radio/TV-reception etc.
Filament Vf 4.2 Volts / If 2.5 Ampere / Indirect / Specified voltage AC/DC

Aligned grids tetrode, used as series modulator. 10W max anode dissipation, 12.5KV peak anode voltage at 3.5A peak current.

Dimensions (WHD)
incl. pins / tip
x 140 x 54 mm / x 5.51 x 2.13 inch
Weight 71 g / 2.50 oz
Tube prices 1 Tube prices (visible for members only)
Information source Taschenbuch zum Röhren-Codex 1948/49   
-- Original-techn. papers.   

cv73_so.png CV73: ratheiser
Anonymous 10 Collector

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Just Qvigstad
CV73: Manufacturer's Literature
Emilio Ciardiello

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Collection of

Documents about this component
  Manufacturer's Data Sheets 326 KB


Forum contributions about this tube
Threads: 1 | Posts: 4
Hits: 3032     Replies: 3
CV73 (CV73)
David Phillips

Note the CV73 has a sister tube. It is a very similar tube with a similar name: CV72.

Some CV72s may be slightly shorter but otherwise it appears identical, having a B7 base also. The number-difference on the labels can be easily overlooked because they look so similar and tend to be found in a group together.

The pinout is ALMOST identical, except for one difference which means neither tube will work if interchanged: the g2 electrode pin-connections are different, (usually causing the screen to be low) with the result that the tube appears to have no emissions.

The close resemblance and apparent no-emission results has nearly caused me to junk a very good CV72 tube.

There is a good picture at . (NoteI have one example of this valve which behaves as if it has a 4-volt heater (reaches full current at 4.6 Volts, not 6.3 as per the spec).

Jacob Roschy

Hello David,

thank you for this information. But I still feel confused about the swapped g2 and g3 electrode pin-connections, as the base diagrams always shows g3 connected to cathode internally. Are probably g2 and g1 swapped ?

So can you please check the base diagrams of both tubes and post the correct ones to here ?

Thanks in advance,


David Phillips

Thanks Jacob -

I have checked this: it is only the screen grid that moves (as you say the beam forming plates and internally connected to the cathode in both tubes).

The screen (g2) is on pin 7 for the CV73, but for CV72 it is on pin 3 (with pin 7 n/c). Pin 3 should be left n/c for CV73).

The control grid (g1) remains on pin 2 for both tubes

The full base diagrams are below. (I also added information about heater behaviour).


Pin Function on CV72 (2!)
1 n/c
2 Control grid
3 Screen grid
4 Heater
5 Heater
6 Cathode and beam forming plates
7 n/c
TC Anode


Pin Function on CV73 (3!)
1 n/c
2 Control grid
3 n/c
4 Heater
5 Heater
6 Cathode and beam plates
7 Screen grid
TC Anode


Jacob Roschy

Hello David,

now I have designed a new base diagram for the CV72 corresponding to your informations.

Now how are the base diagrams for the similar types V1120B and 11E3 ?

Regards, Jacob



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