5642

Apollo 5642 Vacuum Tube

The 5642  (European: DY70) (P/N 154-0051-00, 154-0079-00) is a directly-heated high-voltage rectifier vacuum tube. It has three flexible lead connections and is intended to be soldered into the circuit.

The European type DY70 is very similar (with lower heater current, 140 mA).

It is used in the CRT cathode and post-deflection acceleration supplies in many Tektronix scopes. In typical CRT circuits, the filament/cathode leads of each 5642 have their own secondary winding on the HV transformer, typically a single loop of wire with extra silicone tube insulation.

Key Specifications

Heater	1.25 V, 200 mA
Peak inverse voltage	10 kV
Peak plate current	5 mA
DC plate current	250 μA
Min. supply frequency	5 kHz
Forward voltage drop	40 V @ 4 mA

Links

• RCA 5642 datasheet
• 5642 / DY70 @ radiomuseum.org

Pictures

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  Three 5642s in a 516 HV supply

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  5642s in a 547 HV Supply

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  5642s in a 535/RM35A HV Supply

Used in

Some instruments using part 5642

Instrument	Manufacturer	Class	Model	Description	Introduced
310	Tektronix	Oscilloscope	310A	4 MHz oscilloscope	1955
310A	Tektronix	Oscilloscope	310A	4 MHz oscilloscope	1959
316	Tektronix	Oscilloscope	316	10 MHz 3" tube scope	1959
317	Tektronix	Oscilloscope	317	10 MHz 3" tube scope	1959
360	Tektronix	Oscilloscope	360	CRT Indicator Unit	1954
453	Tektronix	Oscilloscope	453	50 MHz portable dual-trace scope	1965
502	Tektronix	Oscilloscope	502	1 MHz dual beam differential scope	1958
502A	Tektronix	Oscilloscope	502A	1 MHz dual beam differential scope	1963
503	Tektronix	Oscilloscope	503	450 kHz differential-input scope	1960
504	Tektronix	Oscilloscope	504	450 kHz scope	1960
506	Tektronix	Oscilloscope	506	20 MHz scope	1964
513	Tektronix	Oscilloscope	513	18 MHz scope	1950
515	Tektronix	Oscilloscope	515	15 MHz Tube scope	1955
516	Tektronix	Oscilloscope	516	15 MHz dual-trace scope	1960
524	Tektronix	Oscilloscope	524AD	TV waveform monitoring scope	1953
529	Tektronix	Audio/Video	529	TV Waveform Monitor	1965
533	Tektronix	Oscilloscope	533	15 MHz oscilloscope	1958
535	Tektronix	Oscilloscope	535	10 (15) MHz dual-timebase scope	1954
536	Tektronix	Oscilloscope	536	11 MHz X–Y oscilloscope	1957
543	Tektronix	Oscilloscope	543	30 MHz oscilloscope	1958
543A	Tektronix	Oscilloscope	543A	30 MHz oscilloscope	(?)
543B	Tektronix	Oscilloscope	543B	30 MHz oscilloscope	1964
545	Tektronix	Oscilloscope	545	30 (33) MHz oscilloscope	1955
545A	Tektronix	Oscilloscope	545A	30 (33) MHz oscilloscope	1959
545B	Tektronix	Oscilloscope	545B	30 (33) MHz oscilloscope	1964
547	Tektronix	Oscilloscope	547	50 MHz oscilloscope	1964
551	Tektronix	Oscilloscope	551	27 MHz scope	1958
555	Tektronix	Oscilloscope	555	Dual beam 30 MHz scope	1959
556	Tektronix	Oscilloscope	556	50 MHz dual beam scope	1966
560	Tektronix	Oscilloscope	560	1 MHz scope	1961
561	Tektronix	Oscilloscope	561	10(4) MHz "General Purpose Scope"	1961
561A	Tektronix	Oscilloscope	561A	10(4) MHz "General Purpose Scope"	1962
564	Tektronix	Oscilloscope	564	Split-Screen Storage Scope	1962
567	Tektronix	Oscilloscope	567	Sampling scope	1962
570	Tektronix	Curve Tracer	570	Curve tracer for tubes	1955
575	Tektronix	Curve Tracer	575	Curve tracer for transistors	1957
581	Tektronix	Oscilloscope	581	100 (95) MHz oscilloscope	1959
581A	Tektronix	Oscilloscope	581A	85 MHz oscilloscope	1963
585	Tektronix	Oscilloscope	585	100 (95) MHz oscilloscope	1959
585A	Tektronix	Oscilloscope	585	85 MHz oscilloscope	1963
647	Tektronix	Oscilloscope	647	50 MHz scope	1963
647A	Tektronix	Oscilloscope	647A	100 MHz scope	1967