Relay-Protected VOM
The VIZ model WV-520B is a general-purpose multimeter with both a fuse and a relay to protect against overloads. A taut-band meter with color-coded scales provides 100,000-ohms-per-volt sensitivity for DC voltage measurements and 10,000-ohms-per-volt for AC voltages.
Eight DC voltage ranges cover from 0.1 volt full-scale to 1,000 volts, five AC voltage ranges cover from 10 volts to 1,000 volts, resistance readings are between 0.5 ohm and 20 megohms in four ranges, DC current from 10 microamperes full scale to 10 amperes, and two ranges of decibels. A polarity reversing switch for DC readings, and an overload reset button are supplied on the panel.
With test leads, spare fuse, and operating manual, model WV-520B sells for $68.
Portable Dual-Trace Scope
Motorola Communications Division now offers model A-1004A dual-trace 5-inch portable scope. Vertical bandwidth is 15-MHz, and the maximum vertical gain of each channel is 0.005 volt (5 millivolts), and the horizontal sweep has times from 0.2 microsecond-per-centimeter to 0.5 second per division, plus an X5 magnifier.
In addition to the usual triggered scope refinements, model A-1004A has three pre-set horizontal-sweep times for TV vertical, TV horizontal, and VITS. Automatic triggering provides a horizontal line even when there is no vertical input.
Front panel controls have been simplified, and high-stability circuits are used to minimize the need for internal adjustments or calibration.
Portable Digital Multimeter
Model 272 digital multimeter is assembled and calibrated by EICO, and it sells for $69.95. Four ranges of five functions allow measurements of DC up to 1000 volts, AC to 600 volts, AC and DC current to 1000 milliamperes, and resistances up to 1 megohm on the 0.3-inch LED 3-digit display.
Four penlight cells power the meter, which also features automatic zero, automatic polarity for DC readings, overload protection, and 10-megohms input impedance for voltage readings. Accuracy is rated at 0.50 /0 for DC volts and 1.00 /0 for other functions.
1-GHz Frequency Counter
A direct-reading 4-range frequency counter that is pushbutton con trolled between 10 Hz and 1 GHz is offered by Sencore. Model FC51 counter is rated at an accuracy of 0.5 parts-per-million (PPM). Push buttons select the four frequency ranges and two reading rates.
There are three inputs, also selected by pushbuttons.
The 50-ohm input has an average sensitivity of 100 millivolts from 10 MHz to 1 GHz, and it can be used with an external cable, an untuned pickup loop (included), or the adjustable antenna that's included.
In addition, the model WBA52 wide-band amplifier can be plugged into the 59-ohm input to increase the sensitivity to 5 millivolts. Model WBA52 is an optional accessory.
Crystals can be checked for frequency by plugging each one into the "crystal check" socket and pushing the "crystal" button.
The 1-megohm input (with its own sensitivity control) has 10 millivolt sensitivity over most of the range between 10 Hz and 100 MHz.
FC51 counter can be powered either by 120 volts AC or by 12 VDC from any cigarette lighter in vehicles. It is priced at $975 with leads and antenna.
Pushbutton CB Generator
Pushbutton selection of all 40 CB channels is one feature of the phase-locked-loop (PLL) model 266 RF generator offered by Hickok.
The RF attenuator is double shielded and metered to provide signals down to 0.3 microvolt. Level of the IF frequency is adjustable. In addition to the usual 455-kHz frequency, a front-panel socket accepts crystals (1-MHz to 20-MHz) for other IF frequencies.
Model 266 CB Signal Generator with bright LED channel readout sells for less than $500.
Digital Multimeter
Data Precision offers model 258, which has 4-1/2 digits of low-drain Liquid-Crystal Display (LCD) read out. Another unusual feature is the measurement of AC volts by a "true-RMS" method. Model 258 measures AC and DC volts down to 10 microvolts, AC and DC current, and resistances to 20 megohms. All DC voltage ranges are rated at +0.050/0. A calculating-converter LSI module allows true-RMS operation of AC voltage measurements.
Low-drain circuits and the LCD display together reduce the current to a low value, permitting up to 40 hours operation from NiCad batteries between recharges. A blinking decimal point warns that only 10 minutes of operation remains before recharging is needed.
The "TriPhasic" conversion sys tem provides zero setting 2 1/2 times per second just before each conversion. This is said to eliminate tracking discrepancies.
Model 258 sells for $295, including carrying case, battery pack, test leads, battery charger, and instruction manual. Optional accessories are available.
Power Supplies With Digital Readout
Model DG-4 " Voltage-Control Center" developed by PTS Electronics has four variable regulated voltage sources that can be measured by the internal digital voltmeter. Either positive or negative voltages can be selected by switches.
The BIAS supply is adjustable from zero to 15 volts; the SWITCHING supply from zero to 20 volts; the main SUPPLY from zero to 30 volts; and the TUNING supply covers from zero to 30 volts.
A 4-position switch and the 3-digit readout allows very accurate monitoring of the output from any of the four supplies.
Model DG-4 has a vinyl cabinet that's available in walnut, black, or blue, and it sells to dealers for $178.50 net.
Thin IC-Test Clip
Pomona Electronics has developed a thinner test clip for 14-pin and 16-pin in-line ICs. This permits tests where space is limited. The DIP CLIP model 4236 has a molder barrier between each contact to prevent accidental shorts when technicians connect meters or scopes. Price of model 4236 is $5.75.
True-RMS Digital Multimeter
Model RMS-350 Volksmeter digital multimeter from Non Linear Systems features true-RMS measurements of AC voltage and current.
The Liquid-Crystal Display (LCD) has 3 1/2 digits, and the meter has automatic polarity on DC, overload indication, overload protection, and 10 megohms impedance for voltage readings.
Four ranges (five resistance ranges) allow DC readings from 1 millivolt to 1000 volts, AC readings from 1 millivolt to 750 volts RMS, AC and DC current from 1 micro ampere to 1 ampere, and resistance from 1 ohm to 10 megohms. Model RMS-350 Volksmeter sells for $189.
(adapted from: Electronic Servicing magazine, Aug. 1978)
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