Electronics Scene: Four-Channel Digital Delay / Pulse Generator (Elektor Electronics USA, Oct. 1990)

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Bird Electronic Corp. is offering the Model 4410A portable, battery-powered THRU LINE RF directional wattmeter with seven power ranges per element. Accurate measurement of signal power is available within + 5% of reading. Standard elements provide frequency ranges from 0.2-2,300MHz and power ranges from 0.002-10,000W. Special elements provide measurements at frequencies as low as 50kHz.

It's ideal for field-service work, laboratories where high accuracies and low power levels are required, and any application where accurate measurements at milliwatts, watts or kilowatts must be performed simply, quickly, and economically. The 4410A includes a standard 9V alkaline battery.

Other versions are available: Model 4411, battery-powered portable or 115/230V AC (50/60Hz) operation; Model 4412, recharge able Nicad battery or 115/230V AC (50/60Hz) operation; and for fixed location use, Model 4410P, 19" rack panel-mounted configuration with battery or 115/230V AC (50/60Hz) operation.

The 4410A contains an amplifier employing a self-balancing measurement technique.

Its patented bridge circuit has four legs di vided between the base and each of the proprietary plug-in elements. The bridge circuit allows optimum reading accuracies, with a 5,000-to-1 dynamic element range. It is unaffected by temperature extremes.

Elements for the 4410A plug into the element socket and rotate for forward or reflected measurements. The seven overlap ping power levels provided by each element cover 0.002-10W, 0.02-100W, 0.2-1,000W or 2-10,000W. The desired range is instantly selectable by turning a rotary switch on the wattmeter cover. A battery test position is located on the switch.

For information, contact Bird Electronic Corp., 30303 Aurora Rd., Cleveland, OH 44139, or call (216) 248-1200.


Midland LMR has released two-channel portable radios. These crystal-controlled, FM, two-way radios are available in either VHF (model 70-132) or UHF (model 70-232) and feature pre-set automatic noise squelch and optional CTCSS (tone-coded squelch). The new Midland portables meet or exceed MIL SPEC 810C/D specifications for shock and vibration. Size and weight have been reduced through micro-circuit technology and the small new high-energy batteries.

They weigh less than 12 ounces, including battery pack, and provide about eight hours service per battery charge.

The portables offer belt-clip backs, and accessories include external speaker/micro phone, battery chargers, and screw-on stubby helical antennas.

For more information, contact Midland LMR, Marketing Department, 1690 N. Topping, Kansas City, MO 64120, or call 800/ MIDLAND (800-643-5263), Ext. 1690.


B&K-Precision is offering a new hand-held parts tester with digital readout, designed for field service or general industrial applications. Model 815 tests capacitance and resistance in a variety of components, as well as transistors, SCRs, diodes, LEDs and batteries in 26 ranges.

Designed to withstand a five-foot drop, the 815 is also water and overload resistant. Its case seals out grease, dirt and other contaminants.

The Model 815 tests capacitance from 0.1pF to 20µF in capacitors, cables, switches, and other components, with accuracies ranging from 0.75% to 1.5%, resistance measurement spans from 0.1 ohm to 20 m-Ohm. Transistors are tested by measuring h FE values (gain) and i_ceo (leakage). SCRs, diodes, and LEDs are tested for forward junction voltage. Batteries are tested under load for voltage output.

Other features include a 3 1/2 digit 0.8" LCD readout, tilt stand for bench use, test leads, and component insertion sockets.

The B&K-Precision parts tester has numerous applications in electronic and appliance service, industry, and education, and is suited for the hobbyist as well. The 815 is available at local B&K-Precision distributors at a suggested price of $99.

Contact B&K-Precision, Division of Maxtec International Corp., 6470 W. Cortland St., Chicago, IL 60635. Telephone: (312) 889-9087.


Dalanco Spry has developed the Model 250 Digital Signal Processing Board with analog and digital I/O for the PC/AT, and bus compatible microcomputers. Typical applications of this product include instrumentation, machine control, data acquisition, and digital audio.

The Model 250 is based upon the 40MHz Texas Instruments TMS320C25 DSP, and can accommodate the faster TMS320C25-50, the EPROM based TMS320E25, and the newer TMS320C26. It may be operated in stand-alone mode in embedded systems when equipped with the TMS320E25 DSP. The model provides data acquisition for eight single-ended channels at 12-bit resolution and a maximum 300kHz sampling rate.

Two analog output channels are provided, as are a buffered digital I/O expansion connector, and the serial (codec) interface of the TI DSP. The board may be populated with up to 64K words of 0 wait state Program RAM and 128K words of 1 wait state Data RAM. The Data RAM is simultaneously available to the PC and to the TMS320 DSP through an on board memory controller.

The following software is bundled with the Model 250: Assembler, Debugger, FFTs, Signal Spectrum Display, Digital Filter Examples, Record and Playback to/from Disk, and a Waveform Editor.

The Model 250 is priced from $1,095. (40MHz TMS320C25, 4K words of Program RAM, 32K words of Data RAM). For additional information, contact David Langmann at (716) 473-3610, or write Dalanco Spry, 89 Westland Ave., Rochester, NY 14618.



A microminiature digital coded squelch en coder-decoder is now available from Communications Specialists, Inc. The DCS-23 is the latest in a line of add-on tone signaling products. It is compatible with all DCS systems such as: Digital Private Line, Digital Channel Guard, Digital Call Guard, among others. The new board uses surface mounted technology and measures 1.36" x 1.18" x 0.25" which permits installation in all mobile and most portable radios.

All industry standard digital codes are field programmable using simple PCB jumpers.

The board's design uses a crystal controlled CMOS microprocessor, which permits operation on low 6 to 20V DC at 8mA. All connections are made with color-coded jumper wires connected to a microminiature plug and socket. The DCS-23 price is $59.95, and is covered by a one-year warranty. Same day delivery is available from local stock. An illustrated brochure and instruction sheet are available at no cost.

For more information and a complete product list contact: Communications Specialists, Inc., 426 West Taft Ave., Orange, CA 92665 4296, or call (800) 854-0547 or (714) 998-3021.

24-hour FAX (714) 974-3420.


Rapid Systems has developed a modular PC designed for industry. PCXI makes the PC a tool for demanding test instrumentation. It accepts any PC instrumentation, data acquisition, or control cards manufactured to the Industry Standard Architecture (ISA). These cards are mounted in metal shielded modules, which plug into a passive back plane.

PCXI specifications allow for a wide range of test system configurations, such as one consisting of a power supply, CPU, and video modules, plus up to eight modules containing instrumentation cards.

PCXI encloses the cards in EMI/RFI shielded modules. The benefits include greater reliability, and increased immunity to noise and crosstalk between modules.

With PCXI, instrumentation cards can share and collect data based on measurements from several instruments. The modules are fully upgradeable, and interchangeable.

Applications include: OEM systems, calibration lab, ATE systems, field service data acquisition, vibration analysis, educational lab, portable test systems, rack mount test systems, factory automation, and data collection.

For more information contact Rapid Systems, Inc., 433 N. 34th St., Seattle, WA 98103, or call (206) 547-8311.


Vega, the leading manufacturer of high-end wireless systems, is offering a white paper discussing wireless microphone application techniques.

The paper, written by Vega president Gary Stanfill, presents wireless system information, and also offers solutions to many common wireless problems. Topics covered in the 20-pages include frequency selection, interference control, antenna systems, to name a few.

For a free copy of the Vega Wireless Micro phone Application Techniques white paper call (800) 827-6701.

Vega is a manufacturer of wireless systems to professional markets worldwide and a subsidiary of Mark IV Industries. For information contact Vega, 9900 Baldwin Pl., El Monte, CA 91731-2204, or call (818) 442-0782, or (800) 877-1771.


The resurgence of interest in analog sound processing has prompted PAIA Electronics to again offer its popular Hyperflange and Chorus Unit in its line of sound processing kits.

Designed by Craig Anderton, the Hyperflange and Chorus is useful in the studio and for live processing. A hyper triangular control oscillator allows linear time sweeps, and the exponential time sweeps the human ear prefers, both over a range of 71:1.

The unit mounts in a single 1 3 4" standard rack space, and requires a + 12-15V, 200mA power supply.

The Hyperflange and Chorus kit includes printed circuit board, all components, controls and hardware and, an illustrated step by-step assembly and user's manual for $139.95, plus $2 shipping. An optional black anodized front panel with printed control designations is sold separately at $15.95, plus $2 shipping. Both are available from PAIA Electronics, 3200 Teakwood Lane, Edmond, OK 73013, (405) 340-6300.


A general purpose dual 50MHz unity-gain bandwidth op amp, the AD827, from Ana log Devices, Inc., is stable driving any capacitive load and features 85dB channel separation. Well-suited for multi-channel video applications, differential phase and gain errors are typically 0.19° and 0.04°, respectively, measured according to PAL and NTSC standards.

Similar high-speed, low-power applications can benefit from the device's 300V/eLs slew rate, 120ns settling time to within 0.1% for + 5V swings, and 100mW power dissipation. In 1,000s, 8-pin plastic mini-DIP and 16-pin SOIC-packaged devices cost $4.50. The AD827's DC performance is suitable for buffering fast 8- and 10-bit analog-to digital converters. With + 5V supplies, the AD827 has 2mV of maximum offset voltage (guaranteed) and typical open-loop gain of 3.5V/mV (500 ohm load). Gain is maintained at 1.6V/mV even into loads as low as 150 ohm.

With + 15V supplies, open-loop gain in creases to 5.5V/mV (1k12), with only 4mV maximum input offset voltage. From either supply, the output can drive current in ex cess of 30mA (minimum). The monolithic AD827 incorporates a pair of AD827 high-speed op amps, and joins a family of high-performance op amps de signed and built with Analog Devices' proprietary complementary bipolar (CB) process. Package options include 8-pin plastic mini-DIP and cerdip, and a 16-pin small outline integrated circuit (SOIC). Operating temperatures range from 0 to + 70°C, - 40 to +85°C, and -55 to + 125°C. Prices in 1,000s begin at $4.50. Contact Analog Devices, Inc., 181 Ballardvale St., Wilming ton, MA 01887, (617) 937-1428.

Four-Channel Digital Delay / Pulse Generator

The Precision Pulse Generator and Digital Delay Generator recently announced by Fieldtech offers high accuracy and precision, a wide range and low jitter.

As a digital delay generator, the four out puts of the unit may be programmed for any interval between 0 s and 1000 s with 5 ps resolution. The standard timebase provides 25 ppm accuracy, but 1 ppm is available as an optional extra. The jitter of any output is less than 50 ps plus 1 part in 108 of the programmed delay. All outputs return to their pre-trigger levels about 800 ns after the longest delay.

As a precision pulse generator, the four time intervals define two pulses for applications that require precisely controlled pulse widths. The position and width of each pulse may be programmed from the front panel or via the GPIB. Front panel BNCS provide fast outputs at TTL, NIM, ECL or continuously adjustable levels. These pulses and their complements are available from separate front panel outputs. The outputs may be set to drive either 50-ohm or high impedance loads.

Fieldtech Heathrow Ltd, Huntavia House, 420 Bath Road, Longford, WEST DRAYTON UB7 OLL.


The Kenwood CS4025 oscilloscope is a low-cost 20 MHz model with a 80x100 mm (8x10 div.) screen. Its sensitivity is adjustable between 5 mV/div. and 5 V/div. over the full bandwidth; high-sensitive positions of 1 mV/div. and 2 mV/div. are avail able up to 5 MHz.

The sweep time can be varied from 0.5 us/div to 0.5 s/div; a maximum sweep speed of 50 ns/div. can be achieved with the use of the x10 magnifier.

Cross-talk is specified as at least-40 dB for a 1 kHz sine wave.

A useful vertical amplifier signal output (channel 1) is available, which gives an out put of 50 mV/div. over a bandwidth of 100 Hz to 10 MHz. This enables, for in stance, a frequency counter to be connected for accurate measurement of a waveform at low frequency.

Thurlby-Thandar Ltd, 2 Glebe Road, HUNTINGDON PE18 7DX, Telephone (0480) 412451.

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