Editorial Consultant: Rod Burman

4 X TRIODE VALVES, circa 1920

Four Wireless Valves from the 1920's. All are for battery receivers with there type and maker listed below: -
A= Dario Resistron Bivolt Made in France in around 1928. A Triode with a 1.8 Volt Heater and an Anode voltage of 160 Volts. This valve enabled sets to be built without Transformer coupling between the stages; a resistor and a capacitor were used instead.
B= Dario Power Bivolt Made in France. A power output Triode of around 1930 with a 2-volt Heater.

Bruce Hammond Collection.
C= Osram DE2 Valve of 1926. A Dull Emitter LF Triode with a 1.8 Volt Heater.
D= Mullard D3 with a double green ring around the glass, identifying it as a Dull Emitter LF Triode of 1926 with a 2 Volt Heater and an Anode voltage of 50 to 125 Volts.

A1733

V24 MOV VALVE, 1916

Valve designed by H.J.Round (Captain) . A high frequency amplifying Triode of 1916 still being used in 1937.

A0627

D43 MARCONI VALVE, 1938

Marconi D43 single Diode Valve of 1938.

A0611

WECO VALVE, 1920's

Called the Weco (Western Electric Company) or Peanut Valve. Mullard also produced this valve. Ideal for battery equipment with a nominal 1Volt quarter amp heater, and only 17-45 volts anode.

Introduced by the Western Electric Company in 1919 and developed originally by Hendrik Johannes Van der Bijl as the 215A

The Mullard version complete with 4 pin adapter was advertised in The Meccano Magazine in 1924 for 30 shillings.

A0614

WESTERN ELECTRIC WECO VALVE, 1921

Made in Britain from the American version with a British 4 pin base.
Also made by B.T.H.Co. and called the Weco Valve. Mullard also produced this valve. Ideal for battery equipment with a nominal 1Volt quarter amp heater, and only 17-45 volts anode.

Introduced by the Western Electric Company in 1919 and developed originally by Hendrik Johannes Van der Bijl as the 215A

A0861

MULLARD EE50 VALVE, 1939

Unique valve made by Mullard in 1939, which was never fully produced , no known equipment ever used it.
This sample was found in a cellar at a Radio/TV manufacturer (Bush), probably engineering sample.
The base is a locking type with bent pins to 90 degrees.

Donated by Ray Whitcombe

A0993

MICROMESH PENTODE, PEN B1., 1930's

Standard Telephones and Cables stopped trading their Micromesh range of valves around 1935, This is an indirectly heated Pentode Type PEN B1 output valve, designed for use in battery sets. It has a 2 volt 0.2 amp heater, with a very low HT drain.


Nortel Collection

• Box for the Valve
  

A1302

OSRAM HL410 VALVE, 1928

Osram HL410 was a Battery dull emitter with a 4 volt heater of 1928.

A0633

PHILIPS 'Q' VALVE, 1921

The Philips 'Q' was a space-charge-grid Tetrode, the base had a terminal on the side for the inner grid. With a bright-emitter filament 3.5volts.

Nortel Collection

A1306

'R' VALVE, BBC MARKING AND BASE, 1923

The 'R' Valve was developed from the French hard vacuum valve of WW1 and was made in the UK from 1916 by the Marconi Osram Valve Company. Its use in new equipment declined in 1925 with the introduction of the lower power dull emitter valves.

The first ever broadcast from Savoy Hill in 1923 used these valves in the audio amplifier. This was the first UK Hard Vacuum valve to go into production, historically so important that a company in Europe started making copies for enthusiasts who wished to make early wireless sets work.

A0770

MYERS RAC3 2 VOLT VALVE, 1922

Elmer B Myers one of the directors and chief engineers, designed and marketed the RAC3 Audion aiming for the business of the amateur operator rather than the broadcast trade.
This tube was first advertised in December 1920.
It is a Triode with a 4 volt filament.
Made by the Canadian company, E.B.Myers, of Montreal.

A0641

THORPE K4, 1927

Helix wound anode valve. The Thorpe K4 was a tetrode of the space charge grid type. It was intended primarily for use in the Unidyne or Solodyne circuits which were popular at that time.
The advantage of this valve was that no separate anode voltage supply was required, as both anode and inner grid were fed from the 6 volt filament battery. In the period 1925-1927 the K4 valve was offered for sale by at least three vendors in London, but although distributed by Bower Electric Ltd was not advertised by them.

A0598

LOEWE 3NF VALVE, 1929

3 x triodes, Cathode 4V- anode 90V.
One of the most fascinating valves you will ever see, the Loewe 3NF incorporates three triodes, two capacitors and four resistors in a single glass envelope. The inclusion of the passive components reduced the number of pins required to six, but to avoid them contaminating the vacuum, they are each sealed inside a glass tube.

One of the reasons for the development of this amazing device was that in Germany, there was a tax on receivers based on the number of valves in the set, so in 1926, Loewe Radio A.G introduced the 3NF, and also another multi-valve, the 2HF, which contained two screen-grid tetrodes, two resistors and a capacitor, intended for use as a two-stage RF amplifier.
The original Loewe multi-valves are masterpieces of glass work, which must have been very expensive to manufacture, so later versions used a mica supports, and the glass was given an aluminium outer coating to hide the less elegant internal structure.
An obvious drawback of putting three valves in a single envelope is that if one filament fails, the whole device becomes useless, but to counter this disadvantage, Loewe offered a repair service to replace failed filaments.

A0601

ARCTURUS No 127, 1929

Triode, indirectly heated, with 5 pin Base.
The blue colour was used as a trade mark of the Arcturus Radio Tube Company.

A0600

SIEMENS AND HALSKE 'OR' VALVE, 1922

Tetrode of 1922 made in Germany by Siemens and Halske.

A0602

MULLARD ORA VALVE, 1923

The Mullard ORA Valve of 1923.
The title means Oscillates Rectifies Amplifies.
The three possible main functions of the valve.

Maker known then as the Mullard Wireless Service Company Ltd

A0603

LS3 MOV VALVE, 1920's

The Broadcast station 2LO was listened to by receivers using this valve, known as a loudspeaker valve replacing the need for headphones and speaker horns on crystal receivers. (Loud Speaker valve No3).

A0624

CUNNINGHAM AUDIOTRON VALVE, 1915

The Cunningham Audiotron, used as a detector amplifier.
Launched in 1915 in competition with DeForests Audion Valve.

A0628

DEV MOV VALVE, 1925

The Marconi Osram Valve Companies DEV Triode Valve of 1925, with dull emitter filament. See Item A0630.

A0626

P2 COSSOR VALVE, 1929

Cossor P2 Directly heated battery valve, with Helmet anode.
High Frequency amplifier of 1929.

A0616

DER MOV MARCONI VALVE, 1922

First Dull Emitter valve with a 2 volt heater of 1922. (DER Dull Emitter Receiver) This was a Derivative of the 'R' type with a thoriated tungsten filament of 0.63 Watts ( 1.8 volts 0.35 amps ) which reduced filament power by a factor of 4.
Developed 1st by the Marconi Osram Valve Company.

A0630

S625 MOV VALVE, 1927

Developed by H.J.Round (Captain) for the Marconi Osram Valve Company.
The S625 was one of the worlds first fully screened RF amplifier valve.

A0632

S215 MOV VALVE, 1928

The Marconi Osram Valve Company developed the S215 in 1928.
It was a 2 volt filament screened RF Tetrode, and was the upright version of the S625 See Item A0632.

A0634

MH4 MOV CATKIN VALVE, 1932

The Marconi Osram Valve Company developed the MH4. An indirectly heated Triode, that became the general purpose valve for set makers in the 30's. And was the worlds first all metal valve, the case of this valve (Anode) carried the full HT voltage. See Item A0638 for a Catkin with a cover.

A0637

MS4B MOV CATKIN VALVE, 1933

The Marconi Osram Valve Company Nicknamed this shape as a 'Catkin' A miniature cooled anode tetrode, the idea was to dissipate as much heat as possible from the anode to the air. Inside the can was a metal envelope that was in fact the anode itself, the can was added to prevent the user getting a shock from the anode. This valve is a screened RF Tetrode Frequency Changer.
See Item A0637 for an earlier version.

A0638