The document describes the repair process of a Tektronix CG5001 Calibration Generator. It discusses the errors encountered during the power-up self-test and the components that were found to be faulty. The document also mentions the use of extender cables during the diagnostic and repair process.

Introduced in 1966, the Tektronix 106 Square Wave Generator is a signal generator which can produce fast rise (<1nS @50 ohm loads positive or negative going) or high amplitude (120 Volts, high impedance load) square waves from 10Hz to 1MHz. It is used for oscilloscope calibration, risetime testing and for triggering extremely fast rise (<100pS) tunnel diode pulsers. The 106 uses a combination of vacuum tube and discrete solid-state technology. This is the sort of equipment that was used for development and testing during the NASA Apollo Program through the 1960’s.

The cost of the Tektronix Type 106 was USD 590 in 1966 or about USD 4900 in 2021 dollars. I was fortunate enough to obtain one of these units in decent condition and I was able to restore it to better than factory specification. What … Read More »

The Tektronix TM5006 is a 6-Bay power frame which can host and power either TM5000 or TM500 plug-ins .

Tektronix themselves had about 130 different plug-ins available which comprised power supplies, signal generators, oscilloscopes, multimeters, test oscillators, calibrators, attenuators, filters, logic analyzers, frequency counters, audio analyzers and more. In addition, numerous third parties made plug-ins for the system. The total number of different plug-ins numbered at least 200. The system was introduced in 1972 and was available in some form through at least 1995. The system is remarkably interesting from a technology standpoint because it encompasses the move from discrete transistor circuitry in early equipment, evolving through microprocessor-controlled units in later equipment. The more modern TM5000 equipment also had network interface (GPIB) capability for control and data acquisition.

In terms of cost, a basic … Read More »

Tektronix CG5001/CG5011 Pulse Rise Time Measurement

I wanted to measure the rise time of the normal and fast edge pulses in a new acquired Tektronix CG5011 calibration generator.  The equipment line is as follows:

Tektronix TM5006 mainframe

Tektronix CG5011 Calibration Generator

Tektronix CG5001 Calibration Generator

Tektronix/Tegam 015-0611-01 Pulse Head

HP 83480A Communications Analyzer

HP 83483A Electrical Sampling Module (20GHz)

Background:  The original 015-0311-00/01 pulse head was used in combination with the CG551AP and CG5001 calibration generators. The 015-0611-00/01 pulse head is the later version  used on the CG5010 and CG5011 calibration generators.   The primary differences between the later 0611 and earlier 0311 are:

The 0611 has faster edge rise time of <150 ps or < 160 ps for the Tegam version
The 0311 has slower edge rise time  of <200 ps
The 0611 is larger (taller) than the 0311
The 0611 made by Tegam has an SMA output connector
The 611 made by … Read More »

Tektronix DSA602A Digitizing Signal Analyzer Part 1

I recently had the opportunity to purchase one of these units, and I am thoroughly enjoying the process of  checking its operation and getting to know how to use it.  This unit is a laboratory grade, very accurate digitizing oscilloscope from about 1990.  From the Tek Wiki entry:

Inputs
3 amplifier bays, up to 12 channels (using 11A34 plug-ins)

Resolution
8 bits; averaging of N acquisitions increases by log2(N) up to 14 bits

Display resolution
50 pixels/Div

Sample rate
DSA601, max 1 GS/s; DSA602, max 2 GS/s (one channel, left plugin)

Record length
512 to 32768 samples

Sweep rate
50 ps/Div  to 100 s/Div

ENOB
7.2 bit up to 10 MHz, 6.3 bit @ 250 MHz, 5.7 bit @ 500 MHz, 4.5 bit @ 1 GHz

Screen
magnetic deflection color computer monitor, 10″ diagonal (130 mm × 168 mm), 552×704 pixels, 22×11 infrared touch-screen grid

Power
90-132 V or 180-250 V, 48-72 Hz, 465 W (DSA601A) / 585 W (DSA602A)

Features

Automated signal measurements (rise, fall, period, frequency, width, delay, phase, duty … Read More »

Tektronix Scope-Mobile Cart Repair Part 1

I was lucky enough to obtain a Tektronix 202-2 Scope-Mobile Cart.

Tektronix 202-2 Scope-Mobile scanned overview image

Upon examining it, I found that the scope tray was loose and the tilt mechanism did not function properly.  The cause for this was broken trunnion mounts on both sides of the cart as follows:

Tektronix 202-2 Mobile Cart Chassis Parts

Trunnion Mount and Broken Bosses Overview

Trunnion Mount and Broken Bosses Overview

Three of the four bosses were fractured with the fracture surface indicating tensile overload.  I suspect that the bolts were overtightened and the bosses fractured. Overtightening loaded the bosses in tension by trying to compress the box frame member.  Unfortunately this type of polymer (some type of hard thermoplastic) is not good in tension.

Other mobile carts I have seen use cast aluminum for … Read More »

Tektronix 556 Dual Beam Oscilloscope

I had recently the unique opportunity to acquire a complete Tektronix 556 Oscilloscope setup.  This comprised the oscilloscope itself, the matching scope cart, original manual, probes and 12 plug-in units.  This in itself is rare enough, but in addition, this particular scope has the optically desirable blue phosphor CRT and Tektronix C-27 Camera Bezel.   This 50 MHz bandwidth oscilloscope was the state of the art when it was introduced in the mid 1960’s: Tekwiki Tek 556

This will be the first of many posts and updates as I work my way through checking and restoring this beautiful scope.

And now some images:

Tektronix 556 Oscilloscope

Tektronix 556 Oscilloscope

Tektronix 556 Oscilloscope

Tektronix 556 Oscilloscope

Tektronix 556 Oscilloscope

Thanks!

Shaun Merrigan

Tektronix 7904 Oscilloscope

Here are some images of one 7904 mainframe  with a 7A24 vertical module and a 7B92A horizontal module.  The scope screen shows the pulse from an S52 pulse head; the rise time is about 850ps which translates into a bandwidth of about 412 MHz.  Since the 7A24 plug-in is specified at 400 MHz, this is about right.

Very fast rise time pulse on a Tektronix 7904 with a 7A24 vertical module

This is the same pulse from an S52 pulse head but using an S4 sampling head instead of the 7A24 vertical amplifier

Very fast rise time pulse on a Tektronix 7904 with an S4 sampling head

Shaun Merrigan