Home
New Stuff
Author
Links
Guest book
Web-log
Adverts
Bric-a-brac
Calculators

Components

Ephemera
Events
For Sale
Glossary
History
Hit or Miss
Radios
Transport
Ultra
Vales
Wanted
Metal Puzzles
Articles
Clocks
 

 

Valve Data: Mullard 1926 Valve Leaflet

As this is such an early valve leaflet, it is shown here in the full.  For more information see Mullard Valve Data.

Page 1 Mullard 1926 leaflet

Types D.06 H.F. and D.3 H.F
(Double Red Ring Valves)

These valves are H.F. amplifiers and are also suitable for use in resistance capacity amplifiers.  The anode voltage for normal operation is low (50-100 volts), but when used in a resistance amplifier it should be increased to 100-300 volts.
D.06 H.F.
Filament Voltage 3.0v.  Filament current 0.06A.
D.3 H.F.
Filament Voltage 1.8 to 2.0v.  Filament current 0.3A.  

Anode voltage 50 to 125 volts.  Total emission 8mA.  Approx. Impedance 60,000 ohms.  Normal working slope 0.29 mA/volt.  Amplification factor 17.
Code D.06 H.F. IUZGU Price 16/6.
Code D.03 H.F. IUZIW Price 14/-.

Types D.06 L.F. and D.3 L.F
(Double Green Ring Valves)

These are designed for L.F. amplification and are suitable for operating small loudspeakers. It is advisable to use grid bias with these valves, which possess an impedance of about 16,500 ohms.
D.06 L.F.
Filament Voltage 3.0v (max).  Filament current 0.06A. Approx. Impedance 17,000 ohms. Normal working slope 0.42 mA/volt. Amplification factor 7.
D.3 H.F.
Filament Voltage 1.8 to 2.0v.  Filament current 0.3A. Approx. Impedance 16,000 ohms. Normal working slope 0.4 mA/volt. Amplification factor 6.5.

Anode voltage 30 to 100 volts.  Total emission 8mA.  
Code D.06 L.F. IUZKY Price 16/6.
Code D.03 L.F. IUZMA Price 14/-.

Page 2 Mullard 1926 leaflet

Types D.06 and D.3 Detector
(Double White Ring Valves)

An essential part of every wireless receiving set is a rectifying or "detecting" unit.  This unit, in effect, converts high-frequency oscillations which carry the signal into low-frequency pulses which can actuate a telephone or L.F. amplifier.
The detector valve is therefore a very important link in any receiving set, for on its performance depends the final results obtained from the whole set. 

In order to meet our many enquiries for valves suitable as detectors, we have installed special apparatus for selecting valves which are efficient for this purpose.

These valves are H.F. amplifiers and are also suitable for use in resistance capacity amplifiers.  The anode voltage for normal operation is low (50-100 volts), but when used in a resistance amplifier it should be increased to 100-300 volts.
D.06 Detector
Filament Voltage 3.0v (max).  Filament current 0.06A. Approx. impedance 17,000 ohms.  Normal working slope 0.42 mA/volt.  Amplification factor 7.
D.3 Detector
Filament Voltage 2.0v (max).  Filament current 0.3A.  Approx. impedance 16,000 ohms.  Normal working slope 0.4 mA/volt.  Amplification factor 6.5.

Anode voltage 30 to 100 volts.  Total emission 8mA.
Code D.06 Detector DEKTA Price 16/6.
Code D.03 Detector DEKAB Price 14/-.

Page 3 Mullard 1926 leaflet

Types D.F.A.0 D.F.A.1. D.F.A.3
(Dull Filament Amplifying Valves)

These are power amplifiers using relatively low anode volts and suitable for the largest loudspeakers.  They give high amplification with purity of reproduction.  It is advisable to use grid boas with all of these valves (see table below)

D.F.A.0
This valve takes .35 amp. and requires a 4-volt accumulator for filament supply.
D.F.A.1  D.F.A.4
These require a filament current of 0.25 amp., and small 6-volt accumulators are sufficient to supply this current.
D.F.A.3
This is a .06 amp. filament valve which may be run from dry cells.

GRID BIAS DATA
(for best operating conditions) 

Anode

Approx. Negative Grid Potential
(Volts)

Voltage DFA0 DFA1 DFA3 DFA4
50 3 3 2? 1?
75 5 4? 4 4
100 8 7 6 4?

Page 4 Mullard 1926 leaflet

TYPES

D.F.A.1 D.F.A.0 D.F.A.3
Filament voltage
5.0 volts
Filament voltage
3.5 volts
Filament voltage
5.5 to 6.0 volts
Filament current
0.25A
Filament current
0.35A
Filament current
0.06A
Total emission
25mA
Total emission
20mA
Total emission
15mA
Approx. impedance
5,500 ohms
Approx. impedance
7,000 ohms
Approx. impedance
13,000 ohms
Normal working slope
1.0mA/volt
Normal working slope
0.7mA/volt
Normal working slope
0.6mA/volt
Amplification factor
5.5
Amplification factor
5.0
Amplification factor
7.5
Code DAFON Code NORDA Code IUZBO
Price 22/6 Price 22/6 Price 24/6

TYPE D.F.A.4

A valve suitable for resistance capacity amplifiers.  It has a high impedance, and with an anode resistance of 100,000 ohms and anode voltage of 100-300 volts is recommended.

Filament voltage 5.0 volts.  Filament current 0.25A.  Anode voltage 75 to 100 volts.  Total emission 15mA.  Approx. Impedance 27,000 ohms.  Normal working slope 0.75 mA/volt.  Amplification factor 20.
Code IUZES Price 22/6.

Page 5 Mullard 1926 leaflet

Type L.F. (The Green Ring Valve)
A bright filament valve suitable for low-frequency amplification.  It is advisable to use grid bias of 1, 1? ,2, 3 volts for anode voltages of 30, 50, 70, 90 respectively.  This valve requires a 4-volt accumulator to heat the filament.

Filament voltage 3.2 to 3.8 volts.  Filament current 0.6A.  Anode voltage 30 to 90 volts.  Total emission 5mA.  Approx. Impedance 30,000 ohms.  Normal working slope 0.27 mA/volt.  Amplification factor 8.4.
Code IUZAN Price 8/-.

Type H.F. (The Red Ring Valve)
A bright filament valve of rigid construction designed for use as an H.F. amplifier and detector.  A 4-volt accumulator is recommended for filament heating.  When used as a detector a suitable value of grid leak is 3.0 megaohms with a condenser of .0003 mfd.

Filament voltage 3.2 to 3.8 volts.  Filament current 0.6A.  Anode voltage 30 to 90 volts.  Total emission 5mA.  Approx. Impedance 40,000 ohms.  Normal working slope 0.26 mA/volt.  Amplification factor 9.8.
Code IUZUH Price 8/-.

Both H.F and L.F. valves possess arched filaments, supported at the ends only and entirely free from longitudinal strain.  Two advantages accrue from this: firstly, no danger of over-tension of the filament exists, and secondly, microphonic noises are practically absent in such valves.  A 5-ohm filament resistance is suitable for both.

Page 6 Mullard 1926 leaflet

Type S.3
A general purpose bright filament valve designed to operate on very low anode voltages.  It is suitable for rectification, and high or low frequency amplification.

Filament voltage 3.4 to 3.8 volts.  Filament current 0.6A to 0.7A.  Anode voltage 15 to 50 volts.  Total emission 5mA.  Approx. Impedance 24,000 ohms.  Normal working slope 0.15 mA/volt.  Amplification factor 4.
Code IUDYO Price 20/-.

Type S.6
This is a dull filament valve with a high amplification factor.  It is especially useful for resistance-capacity coupled amplification and also for H.F. and L.F. transformer amplification and detection.  It is fitted with a helmet-shaped cap, as is also the S.3.

Filament voltage 3.0 volts.  Filament current 0.2A.  Anode voltage 20 to 100 volts.  Total emission 10mA.  Approx. Impedance 100,000 ohms.  Normal working slope 0.23 mA/volt.  Amplification factor 22.
Code IUYSX Price 27/6.

These two valves will fit standard anti-capacity clips.

Page 7 Mullard 1926 leaflet (damaged)

Type P.M.4.

This example is damaged, suggested text is in [square brackets]

This valve is designed for power amplification, but is suitable for use in all stages of a receiving set.  The filament is prepared by an entirely new process, whereby the special coating is obtained in the extremely adherent condition, and capable of giving considerable emission at very low temperatures.  In fact, when in full operation the glow from the filament should be invisible in daylight.  An additional advantage is the entirely non-microphonic nature of the filament.  The current consumption is 100 milli-amperes only, and therefore the upkeep costs are low in view of long life and low [battery current] required.

[Filament voltage 3].8 volts.  [Filament curre]nt 0.1A.  [Anode voltage xx ]to 100 volts.  [Total emission] 20mA. [Approx. Impedance ]9,000 ohms.  [Normal working slope] 0.63 mA/volt.  [Amplification] factor 6

Use ne[gative grid bias of 3,4,[5 or ] 6 volts with [an anode voltage of ] 50, [75] and [100] volts..
Code I[   ] Price 22/6.