GENERATORS AND GENERAL PURPOSE METERS
Generators provide a source to be sent into the item being tested and meters are used to read the activity coming in, between and coming out of the item. Meters are usually a mechanical device consisting of a needle that would deflect an amount proportional to what it measures.
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Audio Sine Wave Generators
Hewlett Packard Model 200CD
Audio Sine Wave Generator (1952-1972)One of the classic HP test equipment of the 1950's. HP started their business making audio signal generators for Walt Disney in the 1940's. This generator has a range from 5 Hz to 600 KHz. When HP wanted to replace this with a solid state unit in the 1960's the popularity kept it production into the 1970's.
General Purpose
Meter Equipment
Fluke 8100A Digital Multimeter (1960-1975)
Early digital meters were mechanical counters that made a lot of noise through the clicking of the gears. Later electronic alpha numeric vacuum tubes filled with neon gas call "Nixie Tubes" (developed by Boroughs Corp) were developed. Individual numbers were laid out in one vacuum tube. Each number when activated would trigger the neon gas and highlight the number. The big advantage over the mechanical counter was that it was faster, quiet and accurate.
Later the Nixie tube would be replaced with LED display in the 1970's. Shown below is the Fluke 8000A LED digital multimeter (TOP) in comparison to the Fluke 8100A Nixie tube multimeter.
Television Pattern Generators
Their purpose was to provide a set of pattern to make dynamic adjustments on CRT type televisions. Patterns can range from a set of horizontal lines to dots. Newer generators provided three sets of lines and dots for color television adjustments.
Superior Instruments Co (SICO)- TV Crossbar Generator (1950-51)An early pattern generator for aligning the picture for television. Interesting note is that this model used war surplus parts from World War 2. Notably uses 2- Acorn tubes (type 954) and a military radar tube used in radar applications.
Used war surplus tubes and components and Point to point wiring in SICO Cross-Bar. I had to replace many components with modern equivalents.
CONAR 682 (mid 1975) Digital Color/BW Pattern GeneratorProvides a much more stable pattern than the analog types
Comparison of 25 yearsLEFT: CONAR 682RIGHT: SICO vintage
CONAR uses PC Board and intgegrated circuits compared to point to point wiring and vacuum tubes.
Tube Testers
Weston 685 Vacuum Tube Tester (1930 vintage)
Testing a tube is accomplished by setting the switches and setting the filament voltage as instructed by a table of tube settings in the instruction manual. Notice only 3 tube sockets are shown as only prong tubes were used indicating before 1935 vintage.
Hickok 600 Mutual Conductance Tube Tester (1948-1952).
A roll chart is used to find the tube to test and set the controls. Hickok updated these charts as newer tubes were being made. This model was the standard style for their roll chart mutual conductance testers all the way to the famous model 6000A (1962-1969).
This unit has a new red tonex(TM) cover that I placed on. The original is crimson red and was badly torn.
Superior Instruments Company(SICO) TC-55 (1956-57)Emission Type Tube Tester
In 1934 Hickok patented a simple method to test the tube's actual life under load by measuring mutual conductance using a single ammeter. This invention by Job R. Barnhart became the standard for future higher end Hickok tube testers. The military used Hickok testers extensively.
Sweep Marker and RF Signal Generators
These generators sweep across a specific frequency range and put a marker to help identify the peak on an oscilloscope, while making adjustments to equipment that have multiple peaking point or multiple carriers like television and FM radio sets.
Heath IG-57A FM/TV Post Marker Sweep Generator (1968). Synthesized tunning circuits beginning in the 1970s made instruments like these obsolete.
ABOVE: Layout of ComponentsA set of crystal oscillators make up the major part of this unit.
Hewlett Packard HP 8640B : Analog RF Signal Generator with AM and IF Modulation. 0.512 to 512 MHz frequency range, Has digital frequency readout. Signal lock in feature. One of the best analog signal generators made from 1972 to the 1990s. Early synthesizer based generators were no match in noise levels for many years.
BEFORE SYNTHESIZER DESIGNS: TV and FM radio alignment require certain frequencies to be identified or marked on a visual device such as an oscilloscope so the technician know what is being aligned. This specialized generator sweeps a narrow band of frequencies and highlights or marks key carrier or pilot signals so the technician is adjusting parts for the correct parameter.
ABOVE: Front Panel Controls and Connections. Each rocker switch represents a particular test signal to be used.
BELOW: HP 8640B Bottom view showing cavity oscillator (cylindrical body)
ABOVE and LEFT: Take the top and bottom covers off and you can see why it is so large. Many sections are covered shielded away from each other for noise isolation and dirt/grime protection.
Capacitor and Resistor Magic Eye Checkers
Heath Capacitor Checker Model IT-28 (1950's to 1980)
Inside the Heathkit. This one I built back in the late 1970's. Has served me well.
Superior Instruments Company (SICO) Model 76 CR Tester and Signal Tracer (1953)
This equipment can find the value of a capacitor and resistor. It can check the impedance and quality of a transmission line. It will evaluate the leakage of an electrolytic capacitor and with the 12C8 amplifier tube, trace the signal of an amplifier or radio. As with most multipurpose equipment finding the problem is the goal not precision.
This model uses a magic eye tube instead of a meter to test the quality and the condition of a capacitor. Magic eye tube testers were popular from the 1940's and into the 1960's. They offer a smoother view of trends than mechanical meters. However they were more graphical rather than numeric in data interpretation.
Had to replace out many carbon resistors with film ones because the originals had drifted way out of tolerance. Also had the power supply electrolytics replaced.
SICO designed and sold low cost multipurpose test equipment. They started after the end of WW2 and designed radio and tv servicing equipment using war surplus parts. When you open a SICO piece of test equipment you will often see a "mix bag" of parts (some current and others from WW2). Example would be a specialized tube used for radar applications would be configured as a basic rectifier or a couple of vintage capacitors would be configured to do the job of one capacitor.
Testing A Capacitor The green glow with the shadow at the bottom is the 1629 Magic Eye evaluating the capacitor.
Use of War Surplus Tubes Middle: 1629 Electron Ray Tube Lower Right: 1626 Power Triode tube used as a rectifier.:
FYI: Schematic of the Superior Instruments Cross Bar Generator
Up to now there is no source for an operation manual or schematic. Based on looking at several versions I drew a schematic.
SHOWCASE
Remember when TV Repairman made house calls?
B+K 466 CRT Tester / Rejuvenator (1968) When the TV servicing business was a common place including making "house calls", CRT testers were standard equipment. CRT brigthness drops with continued use due to deteriorating cathodes. This tester can make a definite decison as to KEEP OR REPLACE the picture tube. Many CRT testers like this one were capable to rejuvenate the CRT for a short time by increasing the filament voltage for a short time to remove the impurities deposited on the cathode. Quick fix, quick cash and happy customer, able to watch that World Series or Super Bowl game.
ABOVE: Evaluating a picture tube.
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