555: Difference between revisions

Revision as of 03:41, 9 December 2019

{{{manufacturer}}}

Dual beam 30 MHz scope

Produced from 1959 to 1970

Manuals

(All manuals in PDF format unless noted otherwise)

Manuals – Specifications – Links – Pictures

The Tektronix Type 555, nicknamed "Triple Nickel", is a dual-beam CRT oscilloscope introduced by Tektronix in 1959 and made until the late 1960's, when it was replaced by the 556.

The system is split across two cabinets, the main indicator unit and the external power supply unit. The power supply unit contains the main transformer, rectifiers and regulators for all of the voltages except the filament and CRT HV supplies. The filament and CRT HV voltages are generated in the 555 indicator unit.

The Tektronix 555 takes two letter-series or 1-series vertical plug-ins

Key Specifications

please add

Internals

Type 21 and 22 Timebases

The 555 uses special horizontal plug-ins that contain the trigger and sweep. Early instances of the 555 came with the Type 21 and Type 22 horizontal plug-ins.

Type 21 is suggested for the upper beam and type 22 is suggested as the lower beam time base, as type 22 contains delayed trigger, and only the lower beam horizontal section is provided with delayed trigger pickup circuitry. The Delay multiplier control pot is also provided on the lower beam section.

A rigid plug-in extension for the timebases (part number 013-013) was included with every 555.

Type 21A and 22A Timebases

Later instances came with the 21A and 22A horizontal plug-ins, which use tunnel diodes for triggering. Delayed triggering is supported.

Since the 555 is a dual-beam scope, it is also possible to start one of the sweeps while the other beam is sweeping. The upper-beam sweep and lower-beam sweeps are, in fact, totally independent.

Power Supply and Filament Supply Regulator

The external power supply unit generates all the B+ Voltages (–150, +100, +225, +330, +350 and +500 V) required by the indicator unit. These are fed to the indicator unit through the interconnect cable.

There are two transformers inside the power supply unit – one to generate heater voltages (except for the tubes noted below), the other to generate all the B+ plate voltages.

The heater/filament supply for all the tubes inside the indicator unit are generated by a transformer inside the indicator unit. A saturable inductor, located in the power supply unit, is connected in series with its primary as the control element of an AC regulator circuit. One 6.3 V winding from the indicator unit filament transformer is fed back through the interconnection cable (part number 012-032) to supply heaters of specific tubes in the power supply unit (V624, V634, V664, V684, V694). Moreover, a regulator Tube (2AS-15, a Temperature Limited Diode) is used to sense this filament voltage and derive a control DC current through the saturable inductor, thereby signal closing the control loop.

One of the consequences of this scheme is that it the power supply unit will not energize the plate voltages (except +100 V) without the indicator unit connected, because

the 12AX7 comparators and 6AU6 error amplifiers are heated from the indicator unit, so the main series pass tubes (6080s and 12B4s) are not driven even though they are heated from a transformer in the power supply unit;
The primary of the plate voltage transformer inside the power supply unit is looped via the thermal cutout in the indicator unit, i.e. the plate voltage transformer in the power supply will not get power unless the indicator unit is attached.

Even if one were to power up the power supply itself by bypassing the thermal cut-out and applying local heater voltages to the tubes normally supplied by the indicator unit, the power supply will not regulate as the design employs shunting resistors across the series pass tubes, and can therefore not regulate without a load.

Vertical Amplifier

The Tektronix 555 has a six-section differential distributed vertical output amplifier made of 6DK6 tubes. It is the same as the vertical output amplifier in the 551 and the 545A. An L-C delay line is located between the vertical output amplifier and the CRT vertical deflection plates for each channel.

Twelve 6DK6 tubes per beam are used in the main amplifier. A pair of 6DK6s are used to pick up the trigger signal from the differential drive, and pass it to the horizontal plug-in via a cathode follower as a single-ended trigger signal.

Another pair of 6DJ8s are used as grid-line driver cathode followers, fed by the 12BY7 input driver stage, which takes the differential input from the vertical plug-in. A pair of triodes out of 6DJ8s are used as amplifier to drive beam position indicator neons near the CRT.

Architecturally, the 555, with its four plug-ins, is similar to the 7844.

CRT Circuit

The CRT circuit in the 555 is really two separate modules. It is split between two internal metal enclosures, each one containing a high voltage transformer and associated tubes. The lower beam HV power supply is based on transformer T901 and produces:

CRT anode voltage: +8,650 V
lower beam CRT cathode voltage: -1,350 V
lower beam CRT control grid (blanking) voltage: floating, -1,500 V

The upper beam HV power supply is based on T801 and produces:

upper beam CRT cathode voltage: -1,350 V
upper beam CRT control grid (blanking) voltage: floating, -1,500 V

Rectification and voltage multiplication is performed by a total of six 5642 rectifier tubes. Each of the two HV power supplies is independently regulated using a two-stage common-cathode amplifier based on a 12AU7 dual triode. The oscillator tube is a 6CZ5 power pentode.

The 555 uses the T5550 CRT.

Links

Pictures

front view: two timing plug-ins on top and two vertical plug-ins on bottom
Tek 555 in Delayed Trigger Mode
left side view
555 Internals, left side (upper beam)
right side view
555 Internals, right side (lower beam)
top view
555 Top with with HV Cover off
555 Bottom
Vertical Amplifier (Lower Beam)
555 with P11 phosphor option
555 with P7 phosphor option (fast blue / slow green)
timebase plug-in extender, part number 013-013
555 rear
555 photo from technikum29.de

CRT

CRT
CRT
CRT
CRT
CRT
CRT

Power Supply

external power supply
555 power supply
555 power supply
555 power supply
555 power supply
555 power supply
555 Power Supply - Front
555 Power Supply - Rear
555 Power Supply Internals - Top
555 Power Supply Internals - Bottom
Power interconnect, part number 012-032
Power interconnect, part number 012-032
Power interconnect, part number 012-032

Schematics

555 block diagram
lower beam vertical amplifier
Type 21 trigger
block diagram
CRT circuit
heater regulator
time base interconnect
power interconnect

@@ Line 9: / Line 9: @@
 * [http://w140.com/mmm/tek-555.pdf 555 manual hosted locally]
 * [http://bama.edebris.com/manuals/tek/555 555 manual on BAMA (offline?)]
 * [http://w140.com/tek_555_additional_trigger_source_mod.pdf Modification for Additional Trigger Sources]
 * [[Media:040-0328-01.pdf|Modification for Additional Trigger Sources (PDF, OCR, bad-OCR)]]
 * [http://w140.com/tek_555_operators_handbook.pdf 555 Operator's Handbook (PDF)]
 * [[Media:070-227.pdf|555 Operator's Handbook (PDF, OCR, bad-OCR)]]
-<!-- * [[Media:tek_555_german_intro.pdf|German Introduction the 555 (PDF, OCR)]] -->
 * [http://w140.com/Tektronix_555_dt._Kurzanleitung.pdf German Introduction the 555 (PDF, OCR)]
 * [[Media:tek_555_crt_specs.pdf|555 CRT Specs (PDF, OCR)]]
-<!-- * [http://w140.com/tek_555_crt.pdf 555 CRT Specs (PDF)] -->
 * [[Media:tek_555_fcp.pdf|555 Factory Calibration Procedure (PDF, OCR)]]
-<!-- * [http://w140.com/tek_fcp/tek_555_fac_cal.pdf 555 Factory Calibration Procedure (PDF)] -->
 * [[Media:tek_type_21_22_fcp.pdf|Type 21 and 22 Factory Calibration Procedure (PDF, OCR)]]
-<!-- * [http://w140.com/tek_fcp/tek_type_21_and_22_factory_cal_proc.pdf Type 21 and 22 Factory Calibration Procedure (PDF)] -->
 * [[Media:Tektronix 21a-22a.pdf|21A and 22A section of 555 manual (PDF)]]
 * [[Media:tek_555_section_21a_22a.pdf|21A and 22A section of 555 manual (PDF, OCR, bad-OCR)]]
@@ Line 41: / Line 30: @@
 The Tektronix 555 takes two [[letter-series and 1-series plug-ins|letter-series or 1-series vertical plug-ins]]
-== Type 21 and 22 Timebases ==
+{{MissingSpecs}}
+==Internals==
+=== Type 21 and 22 Timebases ===
 The 555 uses special horizontal plug-ins that contain the trigger and sweep.
-Early instances of the 555 came with the 21 and 22 horizontal plug-ins.
+Early instances of the 555 came with the [[21 (plug-in)|Type 21]] and [[22|Type 22]] horizontal plug-ins.
 Type 21 is suggested for the upper beam and type 22 is suggested as the lower beam time base, as type 22 contains delayed trigger, and only the lower beam horizontal section is provided with delayed trigger pickup circuitry. The Delay multiplier control pot is also provided on the lower beam section.
@@ Line 49: / Line 41: @@
 A rigid plug-in extension for the timebases (part number [[013-013]]) was included with every 555.
-== Type 21A and 22A Timebases ==
+=== Type 21A and 22A Timebases ===
-Later instances came with the 21A and 22A horizontal plug-ins, which use [[tunnel diodes]] for triggering.
+Later instances came with the [[21A]] and [[22A]] horizontal plug-ins, which use [[tunnel diodes]] for triggering.
 Delayed triggering is supported.
 Since the 555 is a dual-beam scope, it is also possible to start one of the sweeps while the other beam is sweeping.
 The upper-beam sweep and lower-beam sweeps are, in fact, totally independent.
-== Power Supply and Filament Supply Regulator ==
+=== Power Supply and Filament Supply Regulator ===
 The external power supply unit generates all the B+ Voltages (–150, +100, +225, +330, +350 and +500 V) required by the indicator unit.
 These are fed to the indicator unit through the interconnect cable.
@@ Line 74: / Line 67: @@
 Even if one were to power up the power supply itself by bypassing the thermal cut-out and applying local heater voltages to the tubes normally supplied by the indicator unit, the power supply will not regulate as the design employs shunting resistors across the series pass tubes, and can therefore not regulate without a load.
-== Vertical Amplifier ==
+=== Vertical Amplifier ===
 The Tektronix 555 has a six-section differential [[distributed amplifier|distributed vertical output amplifier]]
-made of [[6DK6]] tubes.  It is the same as the vertical output amplifier inthe [[551]] and the [[545|545A]].
+made of [[6DK6]] tubes.  It is the same as the vertical output amplifier in the [[551]] and the [[545|545A]].
-An L-C [[delay line]] is between the vertical output amplifier and the CRT vertical deflection plates
+An L-C [[delay line]] is located between the vertical output amplifier and the CRT vertical deflection plates for each channel.
-for each channel.
-x6DK6 tubes are used as main amplifier per beam, 6 each for the push and pull section.
+Twelve 6DK6 tubes per beam are used in the main amplifier.  A pair of [[6DK6]]s are used
-A pair of [[6DK6]] are used to pick up the trigger signal from the differential drive and pass it to Horizontal plug-in as single ended trigger signal via a cathode follower.
+to pick up the trigger signal from the differential drive, and pass it to the horizontal
-Another pair of [[6DJ8]] are used as grid line driver cathode followers, fed by the [[12BY7]] input driver stage, which takes the differential input from Vertical plug-in.
+plug-in via a cathode follower as a single-ended trigger signal.
-A pair of triodes out of [[6DJ8]]s are used as amplifier to drive  beam position indicator neons near CRT.
+Another pair of [[6DJ8]]s are used as grid-line driver cathode followers, fed by the [[12BY7]]
+input driver stage, which takes the differential input from the vertical plug-in.
+A pair of triodes out of [[6DJ8]]s are used as amplifier to drive beam position indicator neons near the CRT.
 Architecturally, the 555, with its four plug-ins, is similar to the [[7844]].
-== CRT Circuit ==
+=== CRT Circuit ===
 The CRT circuit in the 555 is really two separate modules.
 It is split between two internal metal enclosures, each one containing a high voltage transformer and associated tubes.
@@ Line 115: / Line 110: @@
 <gallery>
 Tek 555 front fl2.jpg
-Tek 555 front fl.jpg|front view: two timing plug-ins on top and two vertical plug-ins on bottom
+Tek 555 front fl.jpg      |front view: two timing plug-ins on top and two vertical plug-ins on bottom
 Tek_555-Delayed-Trace.jpg | Tek 555 in Delayed Trigger Mode
-_ps.jpg|external power supply
+_left_int.jpg    | left side view
-_left_int.jpg|left side view
+Tek_555-LHS.jpeg    | 555 Internals, left side (upper beam)
-Tek_555-LHS.jpeg | 555 Internals LHS (Upper Beam)
+_rt_int.jpg      | right side view
-_rt_int.jpg|right side view
+Tek_555-RHS.jpeg    | 555 Internals, right side (lower beam)
-Tek_555-RHS.jpeg | 555 Internals RHS (Lower Beam)
+_top_int.jpg     | top view
-_top_int.jpg|top view
+Tek_555_Top.jpg     | 555 Top with with HV Cover off
-Tek_555_Top.jpg | 555 Top with with HV Cover off
 Tek-555-Bottom.jpeg | 555 Bottom
-Tek_555_V-Amp.jpg | Vertical Amplifier (Lower Beam)
+Tek_555_V-Amp.jpg   | Vertical Amplifier (Lower Beam)
-P11.JPG|555 with P11-option
+P11.JPG         | 555 with P11 [[phosphor]] option
-_P7.jpg|555 with P7-option (fast blue and slow green Phosphor)
+_P7.jpg          | 555 with P7 [[phosphor]] option (fast blue / slow green)
-Tek-555-PS-Front.jpg | 555 Power Supply - Front
-Tek-555-PS-Rear.jpg | 555 Power Supply - Rear
-Tek-555-PS-Top.jpg | 555 Power Supply Internals - Top
-Tek-555-PS-Bottom.jpg | 555 Power Supply Internals - Bottom
-Tek 555 cable 3.jpg|Power interconnect, part number 012-032
-Tek 555 cable 2.jpg|Power interconnect, part number 012-032
-Tek 555 cable 1.jpg|Power interconnect, part number 012-032
-Tek 555 timebase interconnect3.png|timebase interconnect
-Tek 555 block.png|555 block diagram
-lower vert.png|lower beam vertical amplifier
-Tek 555 power interconnect.png|power interconnect
-Tek 555 lvreg.png|heater regulator
-Tek 555 21 trigger.png|Type 21 trigger
-Tek_555_block.png|block diagram
-Tek 555 crt circuit.png|CRT circuit
-Tek 555 crt1.jpg|CRT
-Tek 555 crt2.jpg|CRT
-Tek 555 crt3.jpg|CRT
-Tek 555 crt4.jpg|CRT
-Tek 555 crt5.jpg|CRT
-Tek 555 crt6.jpg|CRT
-Tek 22a front.jpg|22A front
-Tek 22a trigger board.jpg|22A  TD trigger board
-Tek 22a top.jpg| 22A top
-Tek 22a bottom.jpg| 22A bottom
-Tek 21 front.jpg| 21 front
-Tek 21 top.jpg| 21 top
-Tek 21 bottom.jpg| 21 bottom
-Tek 22 front.jpg| 22 front
-Tek 22 top.jpg| 22 top
-Tek 22 bottom2.jpg| 22 bottom
-Tek 21a front.jpg| 21A front
-Tek 21a top.jpg| 21A top
-Tek 21a bottom.jpg| 21 bottom
-Tek 21a trigger board.jpg| 21A TD trigger board
 Tek 013-013.JPG|timebase plug-in extender, part number 013-013
 Wellenkino 555-2.jpg
 Wellenkino 555.jpg
 Tek 555 rear.jpg|555 rear
+Tek 555 rear on cart.jpg
+Tek 555 side on cart.jpg
+Tek 555 with camera.jpg
 Tek 555 1050 1.jpg
 Tek 555 1050 2.jpg
@@ Line 180: / Line 144: @@
 Tek 555 1050 12.jpg
 Tek 555 technikum29.de.jpg|555 photo from technikum29.de
+</gallery>
+'''CRT'''
+<gallery>
+Tek 555 crt1.jpg|CRT
+Tek 555 crt2.jpg|CRT
+Tek 555 crt3.jpg|CRT
+Tek 555 crt4.jpg|CRT
+Tek 555 crt5.jpg|CRT
+Tek 555 crt6.jpg|CRT
+</gallery>
+'''Power Supply'''
+<gallery>
+_ps.jpg          | external power supply
+Tek 555 ps no tubes2.jpg|555 power supply
 Tek 555 ps bottom.png|555 power supply
 Tek 555 ps no tubes1.png|555 power supply
-Tek 555 ps no tubes2.jpg|555 power supply
 Tek 555 ps no tubes3.png|555 power supply
 Tek 555 ps no tubes4.png|555 power supply
-Tek 555 rear on cart.jpg
+Tek-555-PS-Front.jpg | 555 Power Supply - Front
-Tek 555 side on cart.jpg
+Tek-555-PS-Rear.jpg | 555 Power Supply - Rear
-Tek 555 with camera.jpg
+Tek-555-PS-Top.jpg | 555 Power Supply Internals - Top
+Tek-555-PS-Bottom.jpg | 555 Power Supply Internals - Bottom
+Tek 555 cable 3.jpg|Power interconnect, part number 012-032
+Tek 555 cable 2.jpg|Power interconnect, part number 012-032
+Tek 555 cable 1.jpg|Power interconnect, part number 012-032
+</gallery>
+'''Schematics'''
+<gallery>
+Tek 555 block.png|555 block diagram
+lower vert.png|lower beam vertical amplifier
+Tek 555 21 trigger.png|Type 21 trigger
+Tek_555_block.png|block diagram
+Tek 555 crt circuit.png|CRT circuit
+Tek 555 lvreg.png|heater regulator
+Tek 555 timebase interconnect3.png|time base interconnect
+Tek 555 power interconnect.png|power interconnect
 </gallery>