Portable calibrator
A compact calibration source of precision dc voltages and accurate ac frequencies is model 249 Scope Calibrator from Cincinnati Electro-systems. Frequencies of 1 kHz, 10 kHz, 100 kHz and 1 MHz have an accuracy of ±0.005 %. The 10 Vdc source has an accuracy of ±0.050/o, while the other dc voltages are rated at 0.10/o accuracy. These standards are useful for calibrating scopes, DMMs and counters. Model 249 sells for $59.95.
Digital multimeter
Special features of the model 8020A Fluke digital multimeter include pushbutton selection of 26 ranges and 7 functions while the meter is held by a left hand, 3 1/2-digit LCD display and a conductance function that allows leak age measurements up to 10,000 Mfg.
Accuracy of the dc volts and ohms ranges has been increased to 0.1%. A carrying case and special probes (that prevent accidental shocks to the operator) are included. Polarity and zeroing are automatic. Three way overload protection is built in, with transient protection to 6 kV.
Price of model 8020A is $169, and many accessories are available for extra charge.
Dual-trace scope
Mini-scope model MS-230 from Non-Linear Systems provides dual-trace 30 MHz operation in a portable scope weighing only 3.5 lbs.
Vertical sensitivity is from 0.01 V to 50 V per division with 12 positions plus a variable. Triggered-sweep times range between 0.05 as and 0.2s per division. Each screen division is 0.25 inch arranged in 5 across and 4 high.
Model MS-230 sells for $559 with input cables and a battery charger that permits battery or ac-line operation. Accessories include a 10X low-capacitance probe and a leather carrying case with shoulder strap and belt loop.
Microprocessor-controlled counter
Philips model PM-6667 counter provides high-resolution measurements of low frequencies and nearly automatic operation.
Seven-digit resolution of low frequencies is obtained by multiple period measurements followed by microprocessor computation of the reciprocal frequency value during each 1s measurement time. The counting ranges cover from 10 Hz to 120 MHz.
A 6-position attenuator allows input levels from 15: mV to 5 V RMS.
Automatic triggering eliminates false counts from noise without control adjustments. The microprocessor selects the range which gives best resolution without overflow while positioning the decimal and lighting the proper Hz, kHz or MHz indicator.
An optional battery pack and carrying case allow the counter to be used for 6 hours per charge away from power lines.
VOM
A hand-sized VOM is offered for $19.95 by VIZ. Model WV-516B has 12 ranges plus dB calibrations, sensitivity of 2000 C /V and measures ac and dc voltages up to 250 V, dc current to 250 mA, resistances up to 500,000 C and decibels between -20 dB and +22 dB. Model WV-516B comes with resistance battery, test leads and a 1-year warranty on parts and labor.
20-MHz scope
Leader Instruments model LBO-308 is a portable, dual-trace 3-inch scope with a bandwidth of 20 MHz.
Operation is from line ac, dc or an optional battery pack. Maximum sensitivity is 2 mV per division, and it is adjustable in 12 ranges plus a variable control. The X5 sweep magnification provides a minimum sweep time of 0.1 uS/div.
Model LBO-308 is priced at $950 with two direct/low-capacitance probes.
Logic-probe tit
Solder, wire, hardware, circuit board, case and all components are furnished by Continental Specialties for the model LPK logic-probe kit that sells for $19.95.
After it is assembled, model LPK probe is powered through attached clip leads from the circuit being tested. Three LEDs indicate a digital high, pulses or a digital low. An internal pulse stretcher detects pulses as narrow as 300 nS and causes the pulse LED to flash at 10 times per second. The internal circuitry is protected against reversal of supply polarity and against overvoltage.