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52

Directly heated tetrode documented in Raytheon receiving-tube sources. Available material confirms tetrode construction but does not establish a narrower functional role confidently.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: U7B
Base pins: 5
Nominal heater: 6.3 V / 300 mA

Description

52 is documented by Raytheon as a Tetrode device. Dual-grid power-amplifier tube usable in Class-B operation with grids tied together or Class-A operation with grid 2 tied to plate. Published ratings, characteristics, capacitances, and representative operating conditions were preserved where applicable.

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: U7B
Base pins: 5
Nominal heater voltage: 6.3 V
Nominal heater current: 300 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

1 physical section, each with unique specifications.

Section 1

Tetrode

X-ray radiationInterelectrode capacitances

Max plate voltage: 180 V

Raytheon type 52 directly heated dual-grid tetrode power amplifier for storage-battery receiving equipment, filament 6.3 V, 0.3 A. Five-prong medium base (corrected parent pin count from 7 to 5). Manufacturer maximum plate voltage 180 V. In Class B push-pull, grids 1 and 2 interconnected, plate maximum 180 V, PEAK PLATE current per tube 75 mA, no-signal current 1.5 mA per tube, two-tube power output about 5 W into 10 kΩ plate-to-plate load. This 75 mA peak PLATE current is not a continuous cathode-current maximum; previous max_cathode_current cleared. In Class A with grid 2 tied to plate (triode connection), plate operating 100–110 V, gm 2.7–3.0 mA/V, mu 5.2–5.8, rp 1900–1750 Ω and output 1.2–1.5 W per tube. Triode connection does not create a second physical section; intrinsic tetrode gm/rp/mu kept 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.

Data set 01

1937 Raytheon Radio Receiving Tubes

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Other

Maximum peak plate current
75 mA
ClassB; PerTube
Plate voltage
180 V
ClassB; PushPull; TwoTubes
Grid 1 and grid 2 bias
0 V
ClassB; PushPull; TwoTubes
No-signal plate current
1.5 mA
ClassB; PerTube
Load resistance plate-to-plate
10000 ohm
ClassB; PushPull; TwoTubes
Power output
5 W
ClassB; PushPull; TwoTubes
Plate voltage
100 V
ClassA; Grid2ConnectedToPlate
Plate current
37 mA
ClassA; PlateVoltage=100V
Load resistance
2000 ohm
ClassA; PlateVoltage=100V
Power output
1.2 W
ClassA; PlateVoltage=100V
Plate voltage
110 V
ClassA; Grid2ConnectedToPlate
Plate current
43 mA
ClassA; PlateVoltage=110V
Power output
1.5 W
ClassA; PlateVoltage=110V

Characteristic

Amplification factor
5.2
ClassA; PlateVoltage=100V
Plate resistance
1900 ohm
ClassA; PlateVoltage=100V
Transconductance
2700 uS
ClassA; PlateVoltage=100V
Amplification factor
5.8
ClassA; PlateVoltage=110V
Plate resistance
1750 ohm
ClassA; PlateVoltage=110V
Transconductance
3000 uS
ClassA; PlateVoltage=110V