GM-70
Power low-frequency triode
Description
Purpose and application
GM-70 is a power modulator triode for low-frequency power amplification in modulator circuits and audio-frequency amplifiers. Its linear directly heated triode structure has also made it widely used in high-power vacuum-tube audio equipment.
Full descriptionCollapse description
Construction
The glass tube uses a directly heated thoriated, carburised tungsten cathode and a large graphite anode. Heater voltage is 20 V and current is 3.1 ± 0.3 A. The four-pin base and electrode arrangement must match the intended socket.
Operating data
Reference ratings include nominal anode voltage of 850 V, maximum anode voltage of 1650 V, maximum anode current of 800 mA and transconductance around 6.7 mA/V. The operating point is selected from the circuit documentation rather than from these limits alone.
Cooling and selection
Cooling is natural air. Maximum dimensions are approximately 185 × 65 mm and mass is no more than 270 g. Before installation, inspect the glass, graphite anode supports, base and pins; specify the required anode execution when ordering.
The operating principle is covered in the vacuum tube article. Related devices are listed under generator and modulator tubes.
Technical details
- Designation
- GM-70
- Device type
- Power modulator triode
- Purpose
- Low-frequency power amplification
- Envelope
- Glass
- Cathode
- Directly heated thoriated carburised tungsten
All specificationsCollapse specifications
- Anode
- Graphite
- Heater voltage
- 20 V
- Heater current
- 3.1 ± 0.3 A
- Nominal anode voltage
- 850 V
- Maximum anode voltage
- 1650 V
- Maximum anode current
- 800 mA
- Transconductance
- Approximately 6.7 mA/V
- Base
- Four-pin
- Cooling
- Natural air
- Maximum dimensions
- 185 × 65 mm
- Maximum mass
- 270 g
Payment & delivery
Orders ship from our hub in Dubai. Partner stock is first transferred to Dubai, then shipped to you.
Dubai stock: 100% before dispatch. Partner stock (Remote stock) and Pre-order: 50% advance payment to start the order and 50% before shipment from Dubai to you.
Availability, lead time, delivery cost and payment terms are confirmed for your order before payment.
Payment & delivery terms