Data set 01
1958 Mullard Receiving Tubes
Published operating points and test conditions from this source.
SECTION 1
Pentode
Application
Application
RF amplifier / speech detector
Characteristics
Heating time
35 s
Voltage Radio Detector Converter ·Pentode
SP4
Indirectly heated high-frequency pentode for RF amplification or speech detection in AC mains receivers. Its ability to serve as either amplifier or detector provides useful flexibility in early transformer-powered radios.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 1
- Base
- -
- Socket code
- B7
- Base pins
- 7
- Nominal heater
- 4 V / 1 A
Description
Indirectly heated HF pentode for RF amplification or speech detection in AC mains receivers.
Socket description
Medium 7-contact
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- -
- Socket code
- B7
- Base pins
- 7
- Nominal heater voltage
- 4 V
- Nominal heater current
- 1 A
- Parallel heater voltage
- -
- Parallel heater current
- -
- Series capable
- No
Terminal pinout
Electrical assignments shared by every tube using this base designation.
No verified pinout is recorded for this base designation.
Section ratings
1 physical section, each with unique specifications.
Section 1
Pentode
X-ray radiationInterelectrode capacitances
- Max plate voltage
- 200 V
- Max screen voltage
- 100 V
Published valve ratings and characteristics promoted where applicable; additional data retained as parameters.
Source-dependent data
Operating conditions by source
Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.