454

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Tektronix 454
150 MHz portable dual-trace scope
Tektronix 454 front

Produced from 1967 to 1974

Manuals
Manuals – Specifications – Links – Pictures

The Tektronix 454 is a 150 MHz portable dual-trace scope designed by Oliver Dalton and introduced in March 1967. It can be seen as an improved 453. The successor 454A was introduced in 1971.

The 454 is the fastest general-purpose Tektronix scope that does not use proprietary hybrid or integrated circuits. It uses a CRT with distributed vertical deflection plates.

Key Specifications

Bandwidth 150 MHz (454: 100 MHz @ 10 mV/div, 60 MHz @ 5 mV/div; 454A: 100 MHz @ 5 mV/div, 50 MHz @ 2 mV/div)
Deflection 5 mV/div to 10 V/div; 1−2−5; 454A: additional 2 mV/div
Sweep 50 ns/div (454A: 20 ns/div) to 5 s/div (1−2−5) plus ×10 magnifier, and variable; timebase B to 50 ms/div
CRT T4540, P31 phosphor standard / P11 optional; +12/–1.96 kV acceleration
Weight 13 kg / 29 lb
Power 90–136/180−272 V, 48−440 Hz, 100–145 W

It is possible to cascade the CH1/CH2 input amplifiers to obtain a sensitivity of 1 mV/Div (454A: 400 μV/div) at a bandwidth of 33 MHz.

The 454 has two ±12 V probe power outputs for P6045 probes.

Links

Documents Referencing 454

Document Class Title Authors Year Links
Service Scope 43 Apr 1967.pdf Article New From Tektronix, Inc. In 1967 1967
Service Scope 49 Apr 1968.pdf Article Quick Check for Tunnel Diodes Tony Bryan 1968
Service Scope 49 Apr 1968.pdf Article Developing a Writing Speed Specification 1968
Service Scope 51 Aug 1968.pdf Article Plug-on Versatility Cal Hongel 1968

Documents Referencing 454A

Document Class Title Authors Year Links
Tekscope 1971 V3 N2.pdf Article New Portables 1971
Tekscope 1971 V3 N3 May 1971.pdf Article The New Portables 1971

Patents that may apply to 454

Page Title Inventors Filing date Grant date Links
Patent US 3453403A Power selection device Eldon Hoffman 1966-08-18 1969-07-01

Internals

The 454 has a 140 ns delay line in the signal path after the input channel switching and before the main vertical amplifier. There is a phase equalizer after the delay line to mitigate the harm done to pulse fidelity by the delay line.

To not have the need of an additional 6V heater supply for the 6 nuvistors built into the 454, the two existing +12 V and -12 V rails are tapped for this purpose to supply 8393 Nuvistors with a 13.5V nominal heater voltage.

Vertical Preamplifier, the attenuators, vertical display switching and positioning is mounted to a common subassembly with the Vertical preamplifier PCA. Thus, servicing any part of the vertical input section requires extensive removal and desoldering of connections. Some of them are not mentioned in the manual.

- Near the right hand probe power connector it is required to desolder two chokes and a braid shield calbe form stands on the main chassis, leading to the attenuator subassembly.

- The rear wire harness is partly soldered to the vertical display switch, and needs to be desoldered for complete removal of the vertical amplifier PCA.

- The metal sheets tongue around the "invert" pull switch may collide with a grounding lug on the middle sheet of the main chassis. Bending the lug away clears enought space to retract the PCA for removal.

Known issues

As mentioned by Mark Vincent in TekScopes forum, the 454, 453 and their A versions have several resistors with their wattage dimensioned too small. This may lead to bias and supply issues.

One example is a non functional delay sweep in a 454 with the delay pickoff pulse not passing the amplifier stage of Q965/Q975. This was caused by R1257 in 12v decoupling network 1 beeing 10% high in value. The found symphtoms were a static voltage of 2.1V at the emitters of Q965, Q975 and about -8.5V on TP970.

454 Modifications

The 454 came in several different modifications that were indicated on the field on the front plate directly below the "454" lettering, left of the serial number field. Known modifications are

  • MOD163D
  • MOD210N - P6047 accessory probes come in 6 ft variant with extra accessories.

It is possible to retrofit the more difficult to obtain 8393 with more common 7586 Nuvistors with the use of a 47Ω 2W dropper resistor for the heater, since the only difference is the higher heater voltage of the 8393. The 47 Ohms resistor will result in a similar 10% underheating (5.7 V of 6.3V) for the 7586 as it is for the 8393 with the ±12V Supplies in the 454. This was successfully tested with a 7586 in the B trigger CF and works without further modifications of the circuit except from the dropper resistor.

It shall be mentioned that a complete retrofit has to be tested to not overload the ±12 V supplies.

Pictures

454

454A


Some Parts Used in the 454

Part Part Number(s) Class Description Used in
120-0470-00 120-0470-00 Discrete component power transformer 454
151-0261-00 151-0261-00 Discrete component dual PNP transistor AM501 AM502 CG5001 CG551AP FG501 FG502 FG503 OF150 OF151 OF152 OF235 OS261 RM502A R1140 R5030 R5031 R7912 067-0679-00 067-0807-00 1101 1140A 1141 1142 1350 145 1450 1480 1481 1482 1485 1501 1801 1900 1910 1980 213 26A1 26A2 2620 285 3A9 3A10 3S1 3S2 3S5 3S6 432 434 4501 454 4601 4602 4610 4612 4620 4632 4634 4701 475 492 492A 492AP 494 494P 496 496P 5A13N 5A20N 5A21N 5A22N 5A26 5L4N 502A 5030 5031 576 690SR 7A22 7A29 7B51 7B71 7J20 7L5 7S11 7S12 7912AD
1N3717 152-0381-00 152-0125-00 Discrete component 4.7 mA, 25 pF tunnel diode 1L40 1S1 1S2 11B1 11B2 11B2A 147A 1470 148 21A 22A 3B4 3B5 408 432 434 453 453A 454 466 491 5T3 544 RM544 546 RM546 547 RM547 556 RM556 7B70 7B71 7D11
8393 154-0461-00 Vacuum Tube (Triode) Nuvistor triode 453 454 1A6 1A7 503
STD704 152-0125-00 Discrete component 4.7 mA tunnel diode 1L40 1S1 11B1 11B2 11B2A 147 R147 147A R147A 1470 148 R148 148-M 149 R149 149A R149A 21A 22A 3B4 3B5 408 432 434 453 453A 454 464 465 466 491 5T3 544 RM544 546 RM546 547 RM547 556 RM556 7B70 7B71 7D11
STD910 152-0310-00 Discrete component 5 mA, 7 pF tunnel diode 454 454A
T4540 154-0504-00 154-0504-01 154-0504-02 154-0504-03 154-0504-04 154-0505-00 154-0505-01 154-0505-02 154-0505-03 154-0505-04 154-0742-00 154-0742-04 CRT rectangular 3⅜" × 3⅞" flat-faced CRT 454


Some Parts Used in the 454A

Part Part Number(s) Class Description Used in
155-0400-00 155-0400-00 Hybrid integrated circuit vertical amplifier 454A
STD910 152-0310-00 Discrete component 5 mA, 7 pF tunnel diode 454 454A