Diode (NOT rectifier) ·Diode-Diode
220DD
Cossor twin-diode valve for detector, AVC, and related signal-rectification functions in battery receivers. Two diode sections permit complementary detector and control-voltage duties within one envelope.
- Sections
- 2
- Base
- -
- Socket code
- B5
- Base pins
- 5
- Nominal heater
- 2 V / 200 mA
Description
Cossor 220DD dualdiode for receiver/amplifier service as specified in the supplied catalogue datasheet.
Socket description
European 5-pin base
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- -
- Socket code
- B5
- Base pins
- 5
- Nominal heater voltage
- 2 V
- Nominal heater current
- 200 mA
- 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
2 physical sections, each with unique specifications.
Section 1
Diode
No fixed ratings are recorded for this section.
Cossor 220 D.D. first physical signal-detector diode, part of a double diode with one common indirectly heated cathode, 2 V 0.2 A heater. Used for reception/signal detection, distinct from second diode used for AVC/delayed AVC voltage. Manufacturer's 1936 narrative does not provide separate numeric maximum current or inverse-voltage ratings; these remain NULL. Both diode sections represented physically.
Section 2
Diode
No fixed ratings are recorded for this section.
Cossor 220 D.D. second physical diode for automatic volume control, including delayed AVC obtained with a small positive cathode offset; first diode handles signal detection. The two diode plates draw current from the same indirectly heated cathode. Heater 2 V 0.2 A. Source does not publish defensible independent current or inverse-voltage maxima, so corresponding fields remain NULL.
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.