Alternatives & variations Download PDF datasheet

7645

Miniature frame-grid twin tetrode designed for compact RF power equipment, with useful output and full-input operation extending to approximately 400 MHz.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: -
Socket code: B9A
Base pins: -
Nominal heater: 6.3 V / 600 mA

Description

7645 is a DualTetrode device in the supplied Amperex literature. Miniature frame-grid twin tetrode, a reduced-height version of the 6939 for compact equipment.

Socket description

Small-button Noval 9-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: B9A
Base pins: -
Nominal heater voltage: 6.3 V
Nominal heater current: 600 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

Tetrode

X-ray radiationInterelectrode capacitances

Amplification factor: 31
Max plate voltage: 250 V
Max screen voltage: 200 V
Max plate dissipation: 5.5 W
Max screen dissipation: 1.5 W
Max grid dissipation: 0.12 W
Max cathode current: 40 mA

Published ratings/characteristics promoted from the source; representative section used for repeated identical systems where applicable.

Section 2

Tetrode

X-ray radiationInterelectrode capacitances

Amplification factor: 31
Max plate voltage: 250 V
Max screen voltage: 200 V
Max plate dissipation: 5.5 W
Max screen dissipation: 1.5 W
Max grid dissipation: 0.12 W
Max cathode current: 40 mA

Second physical tetrode section; electrically identical twin section.

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

1953 Amperex

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Other

Maximum Plate Voltage
250 V
Maximum Screen Voltage
200 V
Maximum Plate Dissipation
3.5 W
Maximum Screen Dissipation
1.5 W
Maximum Grid Dissipation
0.12 W
Maximum Cathode Current
40 mA

Data set 02

1963 Amperex Condensed

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Other

Maximum plate dissipation CCS
5.5 W
PerSection
Maximum plate dissipation ICAS
7 W
PerSection
Plate voltage
180 V
RFPower
Plate current
40 mA
RFPower; PerSection
RF output power
4.2 W
RFPower
Grid voltage
-20 V
RFPower
Grid current
0.6 mA
RFPower
Screen voltage
180 V
RFPower
Maximum frequency at full input rating
400 MHz

Capacitance

Grid-to-plate capacitance
0.15 pF
Input capacitance
6.4 pF
Output capacitance
1.6 pF