RF Power Grid Tubes · Triodes
QB3.5-750 QB3.5/750 CPI Power Triode
Available on request
CPI / e2v
QB3.5-750
CPI ceramic-metal triode with 3.5 kW plate dissipation and 750 MHz maximum frequency, used in UHF TV transmitters and high-power UHF amplifiers.
- Plate Dissipation
- 3500 W
- Max Frequency
- 750 MHz
- Max Plate Voltage
- 8.0 kV
- Max Plate Current
- 1.5 A
Worldwide shipping
Cross-reference support
Grunius BV · Groningen, NL
QB3.5-750
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About the QB3.5-750
The QB3.5-750 is a power triode manufactured by CPI / e2v. CPI ceramic-metal triode with 3.5 kW plate dissipation and 750 MHz maximum frequency, used in UHF TV transmitters and high-power UHF amplifiers.
Key ratings of the QB3.5-750 include tube type Triode, plate dissipation 3500 W, max plate voltage 8.0 kV, max plate current 1.5 A, mu 200 and max frequency 750 MHz.
Typical applications are UHF TV broadcast transmitters, UHF high-power amplifiers, scientific UHF RF sources and defense UHF systems. Notable features: 3.5 kW plate dissipation, 750 MHz UHF operation, high mu 200 and CPI precision manufacture.
Power triodes are three-electrode grid tubes used as RF oscillators and amplifiers in industrial RF heating (plastic welding, induction heating, drying), RF-excited CO₂ lasers, broadcast transmitters and particle accelerators. In oscillator service they work with vacuum capacitors in the tank and matching circuits.
PartnerTubes supplies the QB3.5-750 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 | Triode |
|---|---|
| Plate Dissipation | 3500 W |
| Max Plate Voltage | 8.0 kV |
| Max Plate Current | 1.5 A |
| Mu | 200 |
| Max Frequency | 750 MHz |
| Filament Voltage | 5.0 V |
| Filament Current | 16 A |
| Cooling | Forced air / water |
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
- UHF TV broadcast transmitters
- UHF high-power amplifiers
- Scientific UHF RF sources
- Defense UHF systems
Key features
- 3.5 kW plate dissipation
- 750 MHz UHF operation
- High mu 200
- CPI precision manufacture
Related parts & equivalents
Recommended alongside or as alternatives to the QB3.5-750.
Similar RF Power Grid Tubes
Comparable type, ratings, manufacturer or applications.
Vacuum capacitors for tank & matching circuits
Often ordered with the QB3.5-750 for the same system.
Jennings UCSL 25–200 pF Variable Vacuum Capacitor 25 kV
Jennings Technology (CPI)
Capacitance Range 25–200 pF
Jennings UCSL 15–100 pF Variable Vacuum Capacitor 20 kV
Jennings Technology (CPI)
Capacitance Range 15–100 pF
Jennings UCSL 10–60 pF Variable Vacuum Capacitor
Jennings Technology (CPI)
Capacitance Range 10–60 pF
Frequently asked questions
What is the QB3.5-750?
The QB3.5-750 is a power triode manufactured by CPI / e2v. CPI ceramic-metal triode with 3.5 kW plate dissipation and 750 MHz maximum frequency, used in UHF TV transmitters and high-power UHF amplifiers.
What are the specifications of the QB3.5-750?
Tube Type: Triode; Plate Dissipation: 3500 W; Max Plate Voltage: 8.0 kV; Max Plate Current: 1.5 A; Mu: 200; Max Frequency: 750 MHz; Filament Voltage: 5.0 V; Filament Current: 16 A; Cooling: Forced air / water.
What is the QB3.5-750 used for?
The QB3.5-750 is used in UHF TV broadcast transmitters, UHF high-power amplifiers, scientific UHF RF sources and defense UHF systems.
What are alternatives or related parts to the QB3.5-750?
Related and comparable parts include 8877, 8874, 3CX5000A7, 3CX3000F7, 3CX10000H3 and 3CX30000H7. Contact PartnerTubes to confirm interchangeability for your equipment.
Where can I buy the QB3.5-750?
The QB3.5-750 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=QB3.5-750 or email info@partnertubes.com.