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0.18A Series-string DC Mains Valves. A Continental idea

1950s Valve Manufacture. Anode pressing

1950s Valve Manufacture. Cathode spraying

1950s Valve Manufacture. EF80 Assembly

1950s Valve Manufacture. Glass tube manufacture


1950s Valve Manufacture. Grid winding

1950s Valve Manufacture. Heater production

1950s Valve Manufacture. Making a pressed glass foot

1950s Valve Manufacture. Manufacture of Tungsten wire

1950s Valve Manufacture. Mica supports


1950s Valve Manufacture. Evacuation and testing

The 1T4 Exploded. Manufacturers Diagram

6.3 Volt Valves. Notes on introduction

The 6H6 Diode Family. A sidelight on our exhibits

813 Beam Transmitting Tetrode from RCA. Annotated diagram


A1714 Data-sheet.

A2521. Information from 1957

A3064 Data-sheet.

Acorn Valve Base. Zero Insertion Force

Acorn Valves.


Additional EF91 Information. A supplement to The EF91 article

American Valve Designations (1943). How to interpret the type numbers

Amplification and Valve Characteristics. Technical article on mu, gm and gain-bandwidth

The Anode Bend Detector. A high impedance AM detector

The APP4C. A new valve from Tungsram October 1935


The ARP12. Information from Robert Colman

The Azide Process. Technical article on cathode technology

Barkhausen-Kurz (B-K) Mode Oscillators. Early Centimetric Wave Generation

The Basics of a Colour TV Camera.

Beam Switching Tubes. Counting devices from the 1950's and 1960's


Beam Tetrodes and the 807. Developments in power valves

Bi-Grid Valves.


BVA Influence. The effect of a cartel in a global market

BVA Utility Valves. The WWII civilian radio valves


Catkin Valves. A 'blind alley'?

Ceramic Pick-up Cartridges Modification for Mullard pre-amplifiers.

Ceramic or Moulded Base Caps? Why choose Ceramic?

Compactrons. General Electric introduce up to four valves in one envelope

Continental Imports of the 1930's.


Controlled Warm-up Times. Mullard information from 1963.

The Cossor Wuncell Range. The first oxide-coated valves produced in Britain

The Cossor Point One and Stentor Series Valves. The Kalenised filament at work

Current Limited 0-200V Supply. A hybrid stabilised supply.

The CV172 Noise Diode. The basics of noise figure measurement


The CV287 Voltage Stabiliser. Information on the priming anode

The CV14x Series IR Converter Cells. Early night vision tubes

De Forest and the Audion. Bad theory slows development

The DET1. The first thoriated tungsten dull emitter transmitting valve

Double Beam CRTs. A cossor improvement


Double Triodes ECC81, ECC82 & ECC83 and pin compatibles. A substitution list

DER Valves. Evolution of Early Dull Emitter Valves

Disc Sealed Valves. Also known as Planar valves and Lighthouse Valves

Domestic Rectifiers. Why indirect heating was needed

The Early Mullard Naming Convention. The Meaning of AC044


Early Transmitting Valves. WW1 valve technology

Elliott 803B Computer Video.

Eddystone Radio 6AM5 Box. A spare for their receivers

The Ediswan Safety Cap. To avoid HT across the filament

The EF91 and the Blue Band. Stopping gas emission from the glass.


The EHT Rectifier DY86. Description from Mullard, March 1963.

The 'Electro' Audion. The text of a 1913 advert

Electron Cameras. Design technique from Baird Television 1939

The EM1 and the EM1. The genuine and the ersatz.

EM71 Data-sheet.


EM87: a new voltage indicator. Press release from Mullard in 1961

English Electric X-Band Klystrons. A range of reflex klystrons for Radar receiver local oscillators

English Electric 4.5 inch Image Orthicon. Improved image orthicon giving better picture quality

FM Broadcasting and Signal Detection. The ratio detector etc

Gas Clean-up in Xenon Thyratrons. Information from Mullard in 1954.


Gated Valves. Linear and pulse modulation combined

GEC Oscilloscope Screen Phosphors.

A German Ceramic Valve from 1939. Pinchless construction

Glow Modulators. Electronically controlled light sources

Heater-Cathode Insulation. Ratings explained


Heaters of Mullard Television Valves. Enhancements described in 1962

The Heil Tube. Velocity Modulated Oscillator

A High-Power Pentode and Other New Valves - New Mullard valves from 1933.

Hints on the use of a Pick-Up - from 1928.

The Hudson Filament. For improved Audions


'IM' Long-Playing Needles. Made from thorns

Infra-red Image Converters. An introduction

Inside the 6J6. A broken valve explored

Inside the CV54. A broken valve explored

Inside the EF37. A broken valve explored


Inside the QQE03-20. A broken valve explored

Isolantite. Steatite ceramic.

Keeping Voltages Steady. Voltage references and Voltage stabilisers.

Lend-Lease Valves. American supplies during WWII.

Lighthouse Valves. Octal based disc seal valves


Loewe Multi Valve Repair Policy

A Longer Life for Dial Lamps. Lamp powered by heater tap of 35Z5GT

The 'Magic Three' Valves. Standard valves for the modern superhet

Magic Eye Display Chart. Images of the display from no signal to overload

The Magnetron. Origin and description


Marconi 1928-9 Valve Range Advert

M-OV's Development Laboratory disclaimer label.

M-OV's Screened Grid Valves. S625, S215, MS4 and VMS4

Mercury Vapour Rectifiers. How to use correctly

Method of Repairing Valve Filaments. Repair an R Type


Micromesh PA1 Instruction Sheet. Original Maker's Document

Micropup Valves. Developing airborne radar.

Moving-Coil Loud Speakers 1928

Muirhead D-649-L/E1. Mufax chart recorder maintenance manual.

Mullard Flash-tube General Data.


Mullard Special Quality Valves General Data.

Mullard's 2D4A or Philips KB2. A doubt arises

Mullard's ECC83. A world series valve from Mullard

Mullard's ECL86. A new triode pentode from Mullard (1962)

Mullard's EF36 and EF37. Evolution to an Audio Classic


Mullard's EF86. A world series valve from Mullard

Mullard's EL34. A world series valve from Mullard

Mullard's EL84. A world series valve from Mullard

Mullard's TV4. A cathode-ray tuning indicator from 1936

The Mullard Receiving Valve Naming Convention. How to decode a receiving valve name


Mullard 'Straight' Screened Pentodes. SP valves from Mullard

The Mullard Transmitting & Industrial Valve Naming Convention. How to decode a Mullard Industrial valve name

Mullard xx5x Series Valves. Notes on Mullard's miscellaneous range

Murphy Radio.

Murphy A674SR with Simplex Stereo. Push-pull and parallel amplification with two valves


A New Class B Valve. Mullard introduce the PM2B in 1933

New 'Pentone' Five Electrode Valves. Mullard PM22 and PM24 discussed in 1928.

New Rectifier for Television Receivers. Mullard introduce the PY33

New RF Pentodes from Tungsram. Battery vales for Short-Wave.

New Valve Assembly Method. A semi-automatic aid from Mullard.


New Valves and Circuits. Using the PFL200 from Mullard.

The Nuvistor. A transistor sized valve

Nuvistor Valves - Basics.

Osram Z62. New TV valve from 1939

PCC84 / 7AN7. Brimar information from 1954.


PCF801. Mullard information from 1963.

PCF82 / 9U8. Brimar information from 1954.

Pentagrid Converters. Enter the modern Superhet.

Pentode for Projection Receivers. The new PL820.

Photocell CWS24. A secondary emission photocell


The Philips-Mullard (PM) Series. The first 'azide ' valves

Pioneers of HT Rectifiers. A MOV speciality

PM22 Data-sheet.

Type Q and type V24 Valves. The first hard vacuum valves designed in Britain

QS92/10. Measurements


Quick Heating Valves. Transmitting valves for mobile use

Quiescent Push-Pull. A more efficient output stage for battery sets

R Type Specification.

Radio Set AN/CPN-3. Transportable Radar beacon from WWII

RCA UHF 'Doorknob' Valve 832.


RCA Television Pentodes 1852 & 1853. Valves from 1938

Rectifiers for Pulse Modulators. High voltage devices with low average current

Replacing a Triode Pentode. WWII substitution of a Heptode

Restoring Lost Emission.A hint for early thoriated tungsten valves

The S625 Valve. The World's first HF screen-grid tetrode


The Screen in an EF80. Explanation of the shield and its use

Secondary Emission Amplifiers. Improvements in stability

Secondary Emission Multipliers. Improvements in TV camera design

Series Pass Valves. Valves for voltage regulators

Shortpath Construction.


Should a Glowing Valve be Discarded?.

Silica Valves. A Mullard speciality

Sintered Glass Valve Bases. A Philips development from 1946

Stabilovolt Circuit. Stabilised Power Supply

Still Smaller Hearing Aid Valves. Mullard DF64 and DL64.


Some Notes on the Double Diode Triode. An item from 1933

Storage Tubes. Analogue image storage CRT's

The Strange World of Memory Tubes Computer memory etc.

Strobotron. Flash Tubes

Subminiature Valves. War & Peace


Sylvania 1231 Pentode. New Loctal Base

Telefunken Valve Data - 1944. PDF of shortform data with base connections

Television Line Output Stages. Ediswan Mazda aspects of design No. 8. February, 1959.

Television RF Valve Development. The challenge of high bandwidth gain at 45 MHz

Television and Video Camera Tubes. How they work


Thermistors and Heater Chains. Avoiding thermal shock in series heater chains

Total Harmonic Distortion. Using oscilloscope FFT display and a few calculations

Tube Amp Doctor. A window sticker celebrating 25 years of the company

Tungar rectifiers. A General Electric Booklet

Tuning Indicators. A need to accurately tune superhets


Two New Converter Valves. 6K8

Two New Mullard Television Valves. PCF802 and PC900

The Twystron. high power Wide bandwidth microwave amplification

Type 424 Radar.

Using Cheap DC-DC HT converters.


Valve Care Basics. Make 'em last

Valve Cathodes. A review by J Brian Dance from 1961

Valve Heater Voltages. Effects of under and over voltage

Valve Life. Results of Marconi tests

Valves for Single Sideband Generation.


The Variable mu (μ) Pentode. A brief description

The VCR139A and ACR10. Equal?

VHF Anode Connector. For QQV03-20A etc.

VT Valve Series. UK Post office, RAF and US types

The VT25. A modernised version of the DET1


When a Beginner buys a Valve. A guide to types in December 1924

Wired-in Valves. Reasons for using them

Wiring Jigs. Equipment production tools

X65 Instruction Sheet. Original Maker's Document

Last updated May 28, 2021.
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