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Battery Operated Service Monitor
The VM 520 from Visual Methods, Inc., is a battery powered, black and white service monitor having a 4.5 inch viewing screen and is 100% solid state. It is for the CCTV and CA N technician on a ladder or a pole, in an elevator or anywhere where power is not easily available. The VM 520 has two 75 ohm video signal input connectors; one BNC and one UHF type and also has a 75 ohm F type connector for VHF signal input. The VM 520 can receive broad cast UHF and VHF. The VM 520 is powered by a rechargeable NiCd battery or by an external source of either 12 vdc or 117 vac. An optional carrying case is available to protect the monitor against dropping and rough handling. The case features a neck/shoulder strap, pad ding, and high impact plastic exterior.
Automatic Distortion Meter
NF Circuit Design Block Co., has announced its new automatic distortion meter, the Model E-2001. Manufacturer's specifications indicate the ac curacy of the E-2001 to be 0.1% full scale (distortion meter) with a frequency coverage of 20Hz to 20kHz which is continuously variable in 3 ranges. The E-2001 is also usable as a 10Hz t 200kHz ac voltmeter with a measurement range of 100pv to 100v rms full scale with a reported accuracy of ± 3% at 400Hz. The input range of the distortion meter is said to be 100pv to 100v rms at 100% calibration. The input impedance of the E-2001 is 100K ohms shunted by 70pf unbalanced, and has x and y output terminals for x and y axis hookup with an oscilloscope.
Programmable VHS Video Cassette Recorder
Panasonic Video Systems has expanded its line of Omnivision video cassette recorders with the introduction of its NV-8320 programmable 2-4-6 hour VHS video cassette player/recorder.
This video unit employs 4-video heads for several "special motion" features and a direct drive capstan servo for high stability. It is equipped with a programmable tuner/timer that can be set to turn on and off and change channels up to 8 times during a 14-day period. The new unit also offers 2, 4, or 6-hour recording capability. Model NV-8320 is encased in an annealed aluminum die-cast chassis with components and mechanical parts mounted onto the one-piece chassis to insure overall durability of the sys tem. Other features incorporated into the Panasonic unit include x 9 high speed search with picture at all recorded modes; still/slow/ x 2 speed play operated by remote control in the 6 hour and 2 hour mode as well as noiseless slow motion at 1/20 - 1/4 normal speed. Additional features include Automatic Assembly Recording (AAR), crystal oriented HPF heads, a 4 digit tape counter with memory on/off; built-in RF modulator for CH3/CH4 selection and auto rewind at the end of the tape. Model NV 8320 also has a front panel connection for video, audio, microphone or camera remote and a three mode input select switch (line/tuner/TV). Rear panel connections include BNC video, RCA audio, 8P El AJ connector, and an on-switched ac outlet. The unit also is equipped with an LED dew indicator and 3 pronged ac power cord.
Metric Allen Sets
Moody Tools, Inc., manufacturer of miniature hand tools, announces the addition of three metric Allen sets to its Acu-Min line. The Economy Set (stock #58-0158) contains six Allen drivers and one solid locking, chuck-type, knurled Swivel-top/' handle. The Standard Set (stock #58-0159) includes six Allen drivers and six handles. The Deluxe Set (stock #58-0160) contains six drivers, six handles and six spare drivers. All sets include hardened steel Allen drivers sizes 0.7mm, 0.9mm, 1.27mm, 1.5mm, 2.0mm and 2.5mm.
PCB Ejector Assembly Hand Tool
Bivar, Inc. has just released its PCB ejector assembly hand tool the CTP-1. Designed to make ejector installation easier and faster while providing uniform results, the new tool has a spring loaded centering device for installing ejectors in the desired position onto 1/ 16 in. and 3/32 in. PCBs. A funnel loading spring pin locator allows the parallel acting tool to press the mounting pin through both sides of the ejector, at the same time attaching the ejector onto the PCB. An adjustable stop controls and limits the stroke. Test results indicate a reported savings of 85% in installation time when using the tool.
Digital Frequency Counter
Heath Company has recently announced the introduction of a new 512 MHz portable frequency counter in both kit and assembled versions. The IM 2420 features four gate times and 8-digit resolution for precise readings, according to a Heath spokesperson. It is said to do more than just measure the frequencies of input signals. A period function can give cycle time in seconds, while the frequency ratio function pro vides the ratio between two input frequencies. For more accurate measurements, says Heath, a standby power switch can keep the crystal oven warm for maximum frequency accuracy. The oven is proportionally-controlled to keep the internal time base within 0.1 part per million over a wide temperature range.
The crystal-controlled time base is said to provide excellent long-term stability, with drift controlled to less than 1 ppm per year. The IM-2420 also has provisions for using external time base signals. Four gate times and a large, 0.43 inch-high, 8-digit LED display provide the resolution necessary to measure UHF signals. The IM-2420's 4-15 mV typical sensitivity reportedly allows counting of low level signals. Frequency measurements can be made by direct connection, or by using the optional SMA-2400-1 Swiveling Telescopic Antenna. The IM-2420 can be wired for either 120 or 240 vac operation.
Resistance Soldering Tool
American Beauty's new heavy-duty Resistance Soldering Tool No. 105127 that reportedly handles connections up to 1/2" (12.7 mm) in diameter is now avail able from American Electrical Heater Co. Applications include soldering of heavy gauge wire to terminals, lugs, posts, etc. The tool's heavy electrodes span the joint, pass a low voltage, high amperage current through it. Resistance to the current brings work to soldering temperature quickly, confining the heat to the exact work area. The tweezer-type tool has .125" (3.175 mm) diameter copper-clad, stainless steel electrodes, and operates on 15 to 250 watts of power. There are several power units to choose from. American Beauty resistance soldering equipment ranges from micro-miniature for electronics work to heavy equipment for work with bus bars and copper tubing.
VHF TV Preamplifiers
MA W installers now have a series of VHF TV preamplifiers available from Blonder-Tongue Laboratories, Inc.
These new CMA series preamplifiers are available for low band, high band or broad band use to optimize gain in a specific band and afford high input capability reportedly as high as 25dBmV per channel. An installer can select the preamplifier specifically designed for his particular need. The CMA's (B-T stock no. 4448) gain is said to be 26dB, which is rated exceptionally high for an MATV preamplifier. Each CMA model has an all metal case for added component protection. A wide operating tempera ture range and mast-mount design make the units suitable for tower installations.
To reduce signal degradation, coaxial cable downlead can be used without the need for a separate balun since CMA's have 75 ohm input and output connectors. The units feature a -20dB back matched output test jack to permit monitoring a CMA after installation without interrupting service. All mounting hard ware and cable connectors are supplied with each CMA.
The Mini-Ups, a portable, plug-in uninterruptible power source (UPS) system, designed to protect small electronic equipment from all potential ac power line problems including blackouts, has been announced by Sola Electric. Avail able in 400 va and 750 va models for use with POS terminals, electronic lab monitors and test devices, microcomputers, and other digital electronics, the Mini-Ups contains a sealed maintenance-free, lead-acid type battery. In a blackout situation, the 400 and 750 va units are said to provide up to 20 minutes of regulated power at full load from battery backup. The Mini-Ups operate from a single-phase 115 vac input and provide an output voltage reportedly regulated to ±3% of nominal through input fluctuations as great as +10 -20%. Input frequency fluctuations of up to ±10% of nominal (60Hz) are said to be tightly regulated at the output to ±0.5Hz (one-half cycle). The Mini-Ups also reportedly attenuates electrical noise and holds output harmonics to less than 2% single and 3% total harmonic distortion (THD) into a resistive load.
Portable Digital Multimeter
A new hand held 3-1/2 digit LCD DMM has just been introduced by Eico Electronic Instrument Co., Inc. The Eico 274 measures ac and dc volts, dc current and resistance in 21 ranges. It features single-chip LSI logic, automatic decimal point and overload protection, plus reportedly getting up to 200 hours operation from a single 9 v transistor battery.
The automatic "Lo Bat" indicator warns you of the last 20% of battery life. The large, LCD readouts allow easy viewing.
Accuracy is said to be better than 0.8%, input impedance 10 megohms. The Eico 274 comes complete with 9 v battery, test probes, spare fuse and carrying case.
A thermionic power amplifier is now available from Strathclyde Transcription Developments Ltd. ( Scotland), that dispenses with output protection circuitry and can handle loads from 5 to 20 ohms impedance. The D2000 Tube Amplifier is said to provide continuous out put power of 60 + 60w, 8 ohms, 0.5% maximum distortion; maximum output power 75 + 75w, 8 ohms, 1% clipping; and maximum dynamic power of 200 200w, 8 ohms, 1kHz. The amplifier reportedly will clip cleanly without latching or delayed distortion effects because it has no output protection circuitry; its rapid transient recovery ensures a near instantaneous return to clear amplification. Employing a linear output con figuration, it is load matched to a nominal 8 ohms impedance to provide the rated continuous power; and can handle 5 to 20 ohms impedance. The differential amplifier operates in symmetrical push-pull form, input to output; all stages have wide overload margins apart from the output stage proper. The low feed back, wide-open, loop bandwidth results in negligible intermodulation and loop slew distortion. The unit separates the channels by using two monaural power amplifiers--with their own power sup plies to ensure high channel separation (reportedly greater than 70db) and freedom from dynamic crosstalk. The chassis and power connector are the only common elements. Supply transformers are incorporated for low mechanical noise; a silicon bridge rectifier and stacked electrolytic reservoir capacitors provide a low impedance/high tension supply rail. Output tubes are the newest beam tetrode.
United States Corp. has introduced a new pushbutton DMM. The Model 2380 DMM measures dcv, dc current, acv (TRMS), ac current (TRMS), and resistance-plus- dB, dcv + acv (TRMS), and dc current + ac current (TRMS). With 25,000-count A/D conversion, the 2380 reportedly displays 25% more measurement range than conventional 4-1/2 digit meters. Direct readout in dB permits gain and loss measurements, simply and directly, without complicated calculations. Most decibel instruments provide a single input reference for zero dB, Model 2380 references both 600 and 900 ohms with other references also available. Four 60% overlapping ranges, ensure accurate dB measurements from -40 to +60 dB. Input lead changes are not needed to switch from one function to another. For safety, test leads, front panel inputs and panel markings conform to UL1244 specifications. The Model 2380 DMM, housed in an impact resistant case for ruggedness, is designed and built for the hard working applications of research and development, test and industrial service. Large, bright, LED's provide displays that are easy to read, solid-state input protections avoid damage from overloads and LSI circuitry assures long term reliability. This new multimeter is lightweight (4 lbs.) and measures 3 in. 10 1/4 in.
(source: Electronic Technician/Dealer)