RF Power Grid Tubes · Tetrodes
4-400A Beam Power Tetrode
Beam power tetrode with 400 W plate dissipation for medium-power HF and VHF transmitters and industrial RF systems.
- Plate Dissipation
- 400 W
- Max Frequency
- 175 MHz
- Max Plate Voltage
- 4.0 kV
- Max Plate Current
- 300 mA
About the 4-400A
The 4-400A is a power tetrode. Beam power tetrode with 400 W plate dissipation for medium-power HF and VHF transmitters and industrial RF systems.
Key ratings of the 4-400A include tube type Beam Power Tetrode, plate dissipation 400 W, max plate voltage 4.0 kV, max plate current 300 mA, screen voltage 350 V and transconductance 22 mA/V.
Typical applications are HF medium-power transmitters, VHF linear amplifiers, industrial RF applications and military HF communication. Notable features: 400 W plate dissipation, 175 MHz max frequency, rugged long-life design and well-established circuit data available.
Power tetrodes add a screen grid to the triode structure, giving higher gain and lower drive power. They are widely used in FM and TV broadcast transmitters, HF communications, plasma heating and accelerator RF systems, usually together with vacuum capacitors in the output network.
PartnerTubes supplies the 4-400A worldwide from Groningen, the Netherlands — availability, lead time and price are confirmed per enquiry. Our team can help with equivalent and cross-reference types, sockets and accessories, and supply programmes for OEM and maintenance customers. Interchangeability must always be confirmed for the specific equipment.
Technical specifications
| Tube Type | Beam Power Tetrode |
|---|---|
| Plate Dissipation | 400 W |
| Max Plate Voltage | 4.0 kV |
| Max Plate Current | 300 mA |
| Screen Voltage | 350 V |
| Transconductance | 22 mA/V |
| Max Frequency | 175 MHz |
| Filament Voltage | 6.3 V |
| Filament Current | 2.75 A |
Specifications are indicative and based on published manufacturer data. Always verify against the official datasheet and confirm suitability for your application before ordering.
Applications & features
Used in
- HF medium-power transmitters
- VHF linear amplifiers
- Industrial RF applications
- Military HF communication
Key features
- 400 W plate dissipation
- 175 MHz max frequency
- Rugged long-life design
- Well-established circuit data available
Related parts & equivalents
Recommended alongside or as alternatives to the 4-400A.
Similar RF Power Grid Tubes
Comparable type, ratings, manufacturer or applications.
Vacuum capacitors for output networks
Often ordered with the 4-400A for the same system.
Jennings UCSL 15–100 pF Variable Vacuum Capacitor 20 kV
Jennings Technology (CPI)
Frequently asked questions
What is the 4-400A?
The 4-400A is a power tetrode. Beam power tetrode with 400 W plate dissipation for medium-power HF and VHF transmitters and industrial RF systems.
What are the specifications of the 4-400A?
Tube Type: Beam Power Tetrode; Plate Dissipation: 400 W; Max Plate Voltage: 4.0 kV; Max Plate Current: 300 mA; Screen Voltage: 350 V; Transconductance: 22 mA/V; Max Frequency: 175 MHz; Filament Voltage: 6.3 V; Filament Current: 2.75 A.
What is the 4-400A used for?
The 4-400A is used in HF medium-power transmitters, VHF linear amplifiers, industrial RF applications and military HF communication.
What are alternatives or related parts to the 4-400A?
Related and comparable parts include 4-125A, 4CX250B, 4CX600J, 4CX350A, 4CX1000K and 4CX3000A. Contact PartnerTubes to confirm interchangeability for your equipment.
Where can I buy the 4-400A?
The 4-400A is available from PartnerTubes (Grunius BV, Groningen, Netherlands) with worldwide shipping. Availability and lead time are confirmed on request. Request a quote at https://www.partnertubes.com/contact/?part=4-400A or email info@partnertubes.com.