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Portable DMM
The HD-100 is a new portable DMM from Beckman Instruments, Inc., and is made waterproof and dustproof to resist the elements. It reportedly can with stand the physical impact of accidental drops and has the kind of built-in input protections never before found in other DMMs. Voltage inputs are protected to 1500 vdc or 1000 vrms. Current ranges are protected to 2a/250v while resistance ranges are protected to 500vdc.
The 0-ring sealed ABS plastic case is fire retardant with ribbed side walls that are said to be twice as thick as other meters. The bright "NATO" yellow case is highly visible-easy to spot in a tool box or on a ledge before leaving a job.
Inside, the electronics, including the "large area" LCD and battery, are shock mounted to resist damage from impact.
A common 9v alkaline battery is said to provide up to 2000 hours of continuous operation and up to two years of life under typical conditions. The single rotary switch, patented by Beckman, al lows you to quickly switch to the function and range you are seeking. A quick visual continuity test function, called Insta-Ohms, enables you to check electrical continuity with the speed and ease of an analog type multimeter. In any resistance range, an ohms symbol (12) appears instantly in the LCD when continuity is detected. Each HD-100 comes with a one-year limited warranty. A complete line of Beckman accessories are also available for use with the HD-100. They include a clip-on vinyl case, 2 ac current clamps, deluxe test lead kit, RF probe and a high voltage probe.
Satellite TV Products
Blonder-Tongue Laboratories, Inc. has recently introduced a new line of satellite TVRO earth station products for the MA N market. This new product line, specifically designed to interface with existing MA N systems, consists of: three antenna systems (3.0, 3.65 and 4.6 meters); three new Low Noise Converters; a low cost Earth Station Receiver and mounting tray; two foundation pier kits, and a 4.6 meter pressurization kit. The 3.0 meter antenna system (Model 6001) consists of six stamped aluminum panels, bolted together to form a parabolic surface of revolution, dual polarization focal point feed and mount. This design provides a very low shipping volume and easy handling during installation. The mount provides coverage of geosynchronous satellites located along the orbital arc from 91° to 136° west longitude from anywhere in the contiguous United States. The Model 6002 antenna system combines the 3.0 meter antenna with a 0.65 meter extender ring for in creased gain. The 4.6 meter antenna system (Model 6003) utilizes a high efficiency Cassegrain design substantially reducing satellite terminal costs by providing performance comparable to larger antennas. The 12 panel main reflector is paraboloidal and uses shaped sub-reflector to focus the incoming signal to a receive-only feed horn. The design provides high gain while meeting FCC sidelobe requirements. Blonder Tongue's new Model 6008 Earth Station Receiver and Models 6004, 6005, and 6006 low-noise converters (LNC) are used in combination to enable satellite signals to be carried from the earth station antenna to the receiver over low cost, UHF-type coaxial cable. A low noise converter (a combination of a low noise amplifier and block down-converter) is mounted at the antenna. Satellite signals from the LNC are low noise amplified and the entire 500 MHz band is block converted down from frequencies in the 3.7-4.2 GHz range to frequencies in 270-770 MHz range for in put into the receiver. The Model 6008 twenty-four channel Earth Station Receiver uses threshold extension de modulation (TED) to enhance video and audio quality at low signal levels. Techniques employed in designing TED for the Model 6008 have substantially improved receiver performance, even in the presence of multiple subcarriers.
Impulse noise in the video signal is reduced near the threshold level, and high picture quality is extended to considerably lower operating signal levels than with conventional demodulation. Channel changing is remotely programmable thru BCD code or switch closure. The Model 6008 receiver units are configured so that they may be mounted side-by-side in a 19 inch rack for use in existing head-ends.
4 1/2 Digit Multimeter
The Model 945 from Data Precision is said to be the first full-function, 4 1/2-digit, hand-held multimeter in a "calculator style case." The Model 945 measures both dc and ac voltages with a resolution of 10 uv up to 1000 vdc and up to 700vac in 5 ranges. Both plus and minus are displayed in dc measurements eliminating any possible ambiguity. Resistance is measured from 200 ohm at 10mS/ resolution to 20 M-o in 6 ranges.
There are 5 ranges of dc and ac current measuring from 10na to 2a. Basic ac curacy is ± 0.05%. The unique and very useful feature of the instrument is its ability to characterize diodes as well as to test them. Since the resistance measurement is made by constant current sources, the multimeter directly displays the voltage drop across a diode each decade current step from 100na to 1ma, yielding a 5-point curve. Other loads, both active and passive, may also be characterized using this feature.
Powered by a 9v battery, the Model 945 features a large 0.43" high liquid crystal display of the high contrast type, easily viewed under most lighting conditions.
AC voltage, average sensing with rms calibration, has a basic accuracy of 0.5% over the full power frequency range to 500Hz. At reduced accuracy the instrument will measure from 30Hz to 1kHz. The input impedance for all voltage measurements both ac and dc is 10 M-o in parallel with approximately 100pf. Basic resistance measuring ac curacy is 0.08% of input. While maxi mum open circuit voltage is 3.5v, due to the constant current-source feature the voltage drop across the load is directly measured in the display. This allows the operator to immediately deter mine whether the voltage is high enough to break down diode potentials. and to arrange his measurement multiplier range appropriately to permit accurate in-circuit measurements. All resistance measurements are protected up to 250v rms with no damage to the instrument and no change in calibration. DC current measurement basic accuracy is 0.15% while ac is 0.5%. The current measuring circuits are protected with a 2-a 250-v fuse, easily changed without tools.
Temperature coefficient of all measuring functions is consistent with the specifications and accuracy under normal room temperature. In most cases the temperature coefficient is better than 10% of the specifications so that ambient temperature change would have to exceed 10 C in order to upset the instrument beyond the basic spec limitation. The 945 is designed for truly port able use. The battery is designed to last 100 hours of use before requiring re placement. A low-battery indicator displays before end of battery life. The Model 945 has been designed for industrial use and carries a full two year warranty against all normal use hazards.
Programmable Function Generator
Exact Electronics, Inc. recently announced its Model 607 programmable function generator. The Model 607 is a fully programmable function generator via the GPIB (IEEE 488) bus with ad dress switches on the rear panel to allow easy changes of the GPIB address for maximum flexibility in program de sign. Outputs are sine, square, triangle, ramp and pulse and may be programmed from 1my to 16.6v p-p into 50 ohm, 2 mv to 33.2v p-p unloaded. Amplitude resolution is 3 digits in 4 decade ranges. Accuracy is said to be +-1% of programmed value. The waveforms can be symmetrical about ground or with programmable dc offset. Offset can be programmed from 0-v to 15.6v with 3 digit resolution in 4 decade ranges. Ac curacy is said to be - 1% of programmed offset. Programmed frequency range is 0.001 Hz to 1.66MHz with 3 digit resolution in 9 ranges. Ac curacy is ± 1% of programmed frequency. A VCF (Voltage Controlled Frequency) input allows the generator to be swept or frequency modulated. Gate and trigger modes can be programmed allowing bust and single cycle triggered operation. The triggered or gated wave forms can be programmed to start negative or positive going at 0 degrees, 90 degrees or -90 degrees. Trigger inputs are DTL and TTL compatible. A phase lock input will lock the Model 607 to an external clock or frequency that is within 1% of the programmed frequency. An external dc offset input al lows the dc levels of the output to be modified with an analog voltage allowing closed loop work or amplitude modulation. Frequency, waveform, amplitude, trigger, gate and DC offset are all GPIB programmable and signal commons are isolated for system flexibility.
Satellite TV Receiver
Gillespie and Associates has recently introduced its Model 7500 satellite television receiver which features an Im age Reject Mixer/Down-converter. The downconversion is at the antenna which allows for extended antenna-receiver runs with RG59 cable. The receiver portion features power supply for the LNA, downconverter and tuning voltages, signal strength meter, transponder selector, dual audio and audio-video outputs.
It is finished in a brushed aluminum housing with walnut decorator case.
The image reject mixer/downconverter features an output frequency of 70MHz at 75 ohms, with a noise figure of 13 dB. The Gillaspie IRM is said to deliver a conversion gain of 17 dB with image rejection of 10dB. Power requirement is 18vdc at 100mA. It has a built in LNA bias choke and dc block. Tuning requirements are + 7 to + 18vdc. The in put connector is a type-N female while the output features a type-F female.
Although designed primarily for 3.7-4.2 GHz Band for satellite television reception, it can be adapted for use in other areas.
Dynatracer
The Dynatracer from Non-Linear Systems is a signature pattern producer for the troubleshooting of solid state circuits and components, both in and out of circuit, with no external power applied. It is designed for use with any oscilloscope capable of X-Y mode of operation; has 3 impedance ranges low, med, high and also provides for normal scope operation or DT-1 scope input operation by switching arrangement. The DT-1 dynatracer tests and visually detects faulty IC's, diodes, bridge rectifiers, zeners, FET's, Darlingtons, LED's, voltage regulators, transistors, capacitors, uni-junctions, SCR's and triacs as well as opens and shorts. The DT-1 comes complete with BNC to BNC cables for attachment to scope plus test lead assembly and component test adapter.
Microcomputer
Q1 Corporation has recently introduced its Microlite II microcomputer. This stand alone self-contained office/business system contains the microprocessor as well as all other essential components in a single console that is no larger than an electric typewriter. The unit thus easily fits onto a secretary's return. The typewriter keyboard has 100 key stations, a numeric pad, and 32 function keys. A 24-line by 80-character plasma display is an important factor in making the entire system compact. The Microlite II also houses two 5 1/4 inch floppy disk drives that can store up to 350,000 characters per disk. An optional dot matrix printer can also be housed in the console. Other options include floppy disk drives with a 500-kilobyte 8-inch capacity. Up to four of these drives can be supported. Rigid disk drives with 27 54 208 megabyte removable or 24 40 megabyte Winchester fixed media are available for data base applications where high speed and larger capacity are needed. Magnetic tape drives are also available. Letter-quality printing for word processing applications is pro vided by a separate daisywheel printer, and a 300-line-per-minute line printer provides high volume printing. Provision has also been made for serial communications.
Function Generator
Krohn-Hite announces an improved version of its Model 1000 function generator, the Model 1000A. The special feature of the 1000A is the inclusion of the Waveguard output protection circuit, at no extra cost, which was formerly available only as an added option. The Model 1000A provides 20Vp-p sine, square and triangular waveforms from 0.2Hz to 3MHz and provides 1500:1 frequency tuning range on each of its 3 multiplier bands. Additional features of the Model 1000A include External Volt age Control (VC) of frequency, a calibrated control voltage (CV) output, proportional to frequency, and an auxiliary TTL output.
Logic Timer Detector
Practical Technology recently announced another entry into the Logic Analysis market with the introduction of a general purpose Logic Trigger Detector. The new unit, named LTD-1, is a versatile instrument that simplifies logic troubleshooting by expanding the triggering capabilities of existing test instruments. The LTD-1 generates a trigger signal that can be used to trigger Scopes, Logic Analyzers, Counters and other instruments. The LTD-1 samples and recognizes 2 pre-set combinations of 9 input channels to produce a Trigger Output signal. For further isolation of unique trigger events, the LTD-1 has an A, B, and A delay B Function and Delay selection; also, auxiliary Input and Out puts permit units to be connected in parallel (or serial) for wider (or deeper) trigger combinations. Applications of the LTD-1 include supplementing Practical Technology's Logic Analysis Display Formatter (LADY) (or any other logic analyzer) with additional trigger capabilities, and the use of the output signal to de-multiplex time multiplexed signals on a micro bus or elsewhere.
Noise Analyzer
Pacific Accessory Corporation has recently introduced its Model NA-1 Noise Analyzer Signal Tracer, an instrument used in locating and identifying vehicle noise interference sources. The Noise Analyzer enables the operator to hear noise currents; picks up and identifies radiating noise fields; and, traces signals, tests speakers and checks circuit continuity. Specifications of the PAC Noise Analyzer Signal Tracer include: maximum input sensitivity of 20 microvolts; maximum input voltage to 32 vdc; picks up noise currents to 2 microamps without hum: has pin type conductive probes and a directional inductive probe.
(source: Electronic Technician/Dealer)