New Products (ET/D, Oct 1981)

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Function Generator

Exact Electronics, Inc. has recently announced the release of a new 20MHz 100,000:1 Log Sweep Function Generator with 30 volts p-p output. The Model 528 has a frequency range of 0.001 Hz to 20 MHz and produces sine, square, triangle, positive square and negative square waveforms from the main generator. The auxiliary ramp is also available through the main output amplifier. In the sweep mode the ramp generator is used to internally sweep the main generator either up or down linearly (up to 1000:1) or logarithmically (up to 100,000:1). The start and stop frequencies are independently settable and both may be set and measured using the RUN HOLD and TRIGGER/ HOLD positions of the ramp mode switch. The main generator frequency can be manually swept linearly up to 3 decades or logarithmically up to 5 decades using the start frequency outer dial. A VCF input allows external control of frequency over a 5 decade range in the log mode and a 3 decade range in the linear mode. The start and stop frequency controls are dual function controls providing 10-turn resolution within a one decade range of frequencies or single-turn resolution with band frequency range. As a pulse generator the Model 528 uses the ramp generator to trigger the main generator. Square pulses of either polarity, or single pulses of sinewave, triangle, haver sine, or haver triangle waveforms can be selected.

Two voltage outputs are provided which are controlled by the main generator frequency. V:f (voltage proportional to frequency) is a linear of log output which can be used for X axis drive when sweeping manually, externally, or with the internal ramp. A VCF (voltage con trolled by frequency) output is always linear even when the generator is in the log mode. This allows a linear X axis drive when logarithmically plotting frequencies on a semi-log graph. Other Model 528 features include: t 15v of variable and switchable DC offset, gate, trigger, pulse, and burst modes: variable symmetry: variable start phase; 30v p-p output (15v p-p into 50 Ohms); 80 dB of attenuation; and sync outputs.

Housed in a lightweight aluminum pack age the Model 528 measures 31.8 cm wide x 12.7 cm high x 27.9 cm deep, and weighs approximately 4.5 Kg.

Semiconductor Analyzer

The Parametric Analyzer from UWC Incorporated is an accessory to any oscilloscope with X-Y display capabilities.

Due to the manner in which the Analyzer controls the cathode ray tube's (CRT) beam positioning, the oscilloscope does not impose any specific bandpass or triggering limitations on the Analyzer. The Analyzer allows you to test junction-type devices (such as Pasarttotria •Loalyser• • 0 diodes, transistors, resistors, capacitors and integrated circuits), as well as other discrete devices on a non-powered board without removing the components from the circuit. The Analyzer is self-contained and includes all necessary test probes and cables to connect the unit to your oscilloscope. On model PMA-2 the power cord is permanently attached to the unit. Model PMA-3 uses a molded transformer and cord assembly.

Earth Station Modulator

Blonder-Tongue Laboratories, Inc. has recently announced the availability of an Earth Station Modulator specifically de signed for operation with Television Receive Only (TVRO) satellite terminals where the audio and video are provided as separate base band signals. The ESM-4928 is available for VHF channels 2-13 and Mid Band channels A-1.

The ESM-4928 is a vestigial sideband audio/video modulator with crystal con trolled visual and aural carriers to minimize color beats and audio distortion.

The unit has a calibrated video modulation meter and a true peak-reading LED audio overmodulation indicator to assure precise modulation control. The audio indicator permits adjustment for optimum sound quality. A video low pass filter in the ESM-4928 rejects un wanted subcarrier frequencies of secondary satellite services, preventing adjacent channel interference, and a low loss RF loop-thru diplexer allows higher output levels with lower distortion when combining channels. The ESM-4928 is compact, lightweight (8 lbs) and can be mounted in a standard EIA 19 in. rack.

All indicators and controls are located on the front panel for monitoring and adjusting.

Satellite Splitter

The Ampli-Splitter TVRO multiplexing system from Gillaspie and Associates provides for separate access of two or more satellite receivers to the same antenna and low noise amplifier, including single conversion type receivers utilizing image reject mixer technology. The weatherized and shielded Ampli-Splitter contains a 3.7 to 4.2 GHz line amplifier, a two-way microwave signal splitter with 50-dB port-to-port isolation, and is designed for either up the cable dc powering of the Ampli-Splitter and the LNA, or for separate dc power insertion.

Other independently operating receivers can be added to the system with minimum signal loss by cascading Ampli-Splitters along the extended sys tem.

Voltage Standard

Standard Reference Labs, Inc. has recently introduced a single cell, ovenized, solid state voltage reference standard with guaranteed voltage out put stability of 2ppm/year. Typically, its output changes less than a few tenths of a ppm/year. Model VTS-101SC/2-10, which is housed in a all aluminum case with collapsible prop-up carrying handle, is a rechargeable Gel-Cell battery powered transport standard. It features the prime output Vz value of 6.3 volts nominal and a convenience output of 10 volts. Output is guaranteed to change less than 0.1ppm for every degree Centigrade change in ambient room temperature. This solid state voltage standard reportedly offers several distinct advantages. It produces an output an order of magnitude higher than previously possible freeing the user from traditional worries about thermal voltage errors and providing a level closer to that required for practical application. It can be loaded or even shorted out with out damage or long term effects, and is said to be insensitive to position, vibration, and shock associated with nor mal transportation and handling.

Fiber Optic Converter

A new fiber optic instrument that converts standard multimeters into fiber optic power meters has been introduced by FOTEC, Inc. Called the FOTEC C Fiber Optic Converter, it can be used with any multimeter or voltmeter to measure basic fiber optic system parameters such as fiber attenuation, connector or splice loss, source power coupled into fibers, or signal level at the receiver. While designed with the requirements of laboratory fiber optic measurements as a guide, FOTEC C is also for field service of fiber optic installations. FOTEC C can measure signals in the range of less than 20 nano-watts to over 2 milliwatts of optical power with an accuracy of -± 5%, and with any signal frequency from dc to hundreds of megahertz. It can be used with sources in the 400 to 1100 nano meter range, and is easily recalibrated for various source wavelengths. The output is a linear dc signal calibrated as 1v/uW or 1v/mW on two switchable ranges. When used with a 3 1/2 digit DMM, for example, it gives 1 microwatt resolution on the milliwatt range and 1 nanowatt resolution on the microwatt range. Auto-zero circuitry include in the FOTEC C design allows its high accuracy to be maintained over a broad range of operating conditions. FOTEC C is portable and is powered by a single 9V 1.5 x 3 x 5.25 in. (28 x 85 x 133 mm.) and weighs 7 1/2 oz (210 grams).

(source: Electronic Technician/Dealer)

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