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NL649

Single-ended mercury-filled industrial rectifier for power supplies and back-rectifier service with thyratrons. Rated for approximately 900 V peak inverse voltage and 2 A nominal output.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: DOWN
Socket code: UX4
Base pins: -
Nominal heater: 2.5 V / 7 A

Description

NATIONAL POWER TUBE NL-649 is a sturdy, single-ended, rectifier tube designed especially for indus- trial power rectifier applications and for "back-rectifier" applications in conjunction with a thyratron tube. It is mercury filled for efficiency, long life, and the ability to stand high inverse voltage. NATIONAL ELECTRONICS, INC. GENEVA, ILLINOIS, U. S A. NL-649 RECTIFIER TUBE TECHNICAL INFORMATION do Amperes output (maximum) 2 Instantaneous Amperes output (maximum) 10 Maximum time of averaging anode current (seconds) 5 Maximum peak inverse volts 900 Fi

Socket description

Medium-shell UX 4-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: DOWN
Socket code: UX4
Base pins: -
Nominal heater voltage: 2.5 V
Nominal heater current: 7 A
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

DOWN - 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

Rectifier

X-ray radiationInterelectrode capacitances

Max cathode current: 2 A
Rectifier peak inverse voltage: 900 V
Rectifier nominal output current: 2 A
Rectifier peak forward current: 10 A
Rectifier forward voltage drop: 9 V
Rectifier warm-up time: 20 s

Published ratings and characteristics promoted where canonical fields apply.

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

1956 National Electronics Industrial Tubes

Published operating points and test conditions from this source.

SECTION 1

Rectifier

Other

do Amperes output (maximum)
2 A
Source technical-information table; wording preserved from datasheet.
Instantaneous Amperes output (maximum)
10 A
Source technical-information table; wording preserved from datasheet.
Maximum time of averaging anode current (seconds)
5 A
Source technical-information table; wording preserved from datasheet.
Maximum peak inverse volts
900 V
Source technical-information table; wording preserved from datasheet.
Filament volts
2,5 V
Source technical-information table; wording preserved from datasheet.
Filament amperes
7 +1 A
Source technical-information table; wording preserved from datasheet.
Filament heating time (seconds)
20 s
Source technical-information table; wording preserved from datasheet.
Maximum ac short circuit current (amperes)
125 A
Source technical-information table; wording preserved from datasheet.
Condensed mercury temperature limits (°C)
+ 35 to + 85 C
Source technical-information table; wording preserved from datasheet.
Approximate temperature rise, cond. mercury above ambient (°C)
25 C
Source technical-information table; wording preserved from datasheet.
Net weight (ounces)
3 oz
Source technical-information table; wording preserved from datasheet.
Approx. shipping weight (lbs.)
3 lb
Source technical-information table; wording preserved from datasheet.
5,bMAX
M E D. 4 -PIN
Source technical-information table; wording preserved from datasheet.
Priwted in USA
5-56 GE
Source technical-information table; wording preserved from datasheet.

Characteristic

Typical arc drop at
6 amperes peak (volts) g
Source technical-information table; wording preserved from datasheet.
Typical Anode starting voltage (volts)
16 V
Source technical-information table; wording preserved from datasheet.

Data set 02

1957 National Electronics

Published operating points and test conditions from this source.

SECTION 1

Rectifier

Other

Maximum DC output current
2 A
Maximum instantaneous output current
10 A
Maximum peak inverse voltage
900 V

Characteristic

Filament heating time
20 s
Typical arc drop
9 V
Typical anode starting voltage
16 V

Construction

Filling
Mercury vapor