Input Noise

ITS INFLUENCE ON COUNTER AND PULSE-GENERATOR PERFORMANCE The significance of input noise in counters, pulse generators, and other broadband switching circuits and a method for its measurement are the subjects of the first of three short articles featured this month. The second and third articles describe a new pulse generator and amplifier, both designed for general-purpose laboratory applications. In an externally driven pulse generator, noise introduced in the input circuit determines the...

Info

In dielectric bead1-2 er dielectric constant of bead. If we treat region 1-2 as a section of air-dielectric line and let Z2 Z , th< Zz can be calculated from One method of solving for is to assume a value of , solve for ZQ ( Z2) in equation (2), Z in equation (4) and y0 in equation (5), and then find Z3 from equation (6). At resonant frequency, Zz Z2*. The resonant frequency of the bead pair (Figure lb) may be calculated in a similar manner. Two resonant frequencies exist, one below and one...

Automatic Scanner System

Ing less than 0.01 pF across the component itself. The Scanner System is composed of two main units, the 1771 Scanner Control and the 1772 Scanner Switch. The components under test are connected to the switch unit by long cables, each consisting of 10 wires in a single shielded bundle. The switch unit is similarly connected to the control unit by a long cable. This arrangement is extremely adaptable, since the components can be separated from the switch unit, which can in turn be separated from...

Generation Of Sinesquared Pulses With The Toneburst Generator

Sine-squared, or raised-cosine, pulses are useful in testing broadband transmission systems and. in particular, in video-bandwidth tests of television systems.1 The sine-squared pulse, for instance, resembles very closely the electrical pulse from a television camera corresponding to a scanned white line. The spectrum envelope of a sine-squared pulse is shown in Figure 1 with that of a rectangular pulse for comparison. Above twice the fundamental, the sine-squared pulse has no components of...

R

Where r,, rp, f,, fp, rm and m* are defined by the transformer equivalent circuit of Figure 7. With a little insight it i.s easy to identify the physical cause of the error terms, most of which are proportional to rA and r5, which started all the trouble. By choice of circuit elements, these error terms can be made quite small, even when the lead resistances are quite large and ra is rather small (as it must be for sensitivity considerations). The transformer in the Type 1617 uses Mumetal...

TEirMode Resonances In Precision Coaxial Connectors

It has been common practice to specify the upper frequency limit of a precision coaxial system as the calculated frequency at which the next higher mode above the TEM mode TEn could propagate in the air-dielectric section of the line. It has, of course, been recognized that this mode can propagate in dielectric support beads below this frequency, but the interaction between the TEM and TEn modes is insignificant if the effective electrical length of the bead is so short that a TEu-mode...

Capacitors

Perhaps the largest capacitances that most of us have had to deal with were those in the problems given in circuit-theory textbooks1 where all circuit elements were in ohms, henrys, or farads. While actual capacitors in the farad range didn't seem very practical, we realized it was the principle involved that was important and not the magnitudes. However, students these days may accept such grotesque circuit values without question and, in fact, may have seen capacitors of this value advertised...

Simple Way To Synchronize Magnetic Tape With Oscilloscope Trace

During some recent investigations of transient sound pulses in our Engineering Department, it was necessary to 1 Using a Photocell Where it Counts, General Radio Experimenter, October 19 12. synchronize the starting of an oscilloscope trace with the position of the pulse on a magnetic recording tape. The Type 1536-A Photoelectric Pick-off 1 proved very well suited to this task. Figure 1 shows the photoelectric pickoff mounted on the tape recorder. A piece of aluminum tubing was screwed to the...

Automatic Capacitortesting Systems

The inspection bottleneck was broken by GR's I 680-A Automatic Capacitance Bridge Assembly, announced in I 964. Many users who formerly tested capacitors at a rate of ten a minute at best are now testing at rates better than I 20 a minute In this issue we describe some of the complex automatic testing systems designed around this bridge and two new accessories, the 1781 Digital Limit Comparator and the I 770 Scanner System. The increasingly demanding requirements for extreme reliability in...

Specifications

Probe Travel 50 cm. Scale in centimeters each division is 1 mm. Scale Accuracy 0.1 mm - - 0.05 . Frequency Range 300 MHz to 8.5 GHz usable to 9 GHz . At 300 MHz, the slotted line coverB a half wavelength. Operation below 300 MHz is possible by use of lengths of Type 874 Air Lines. Constancy of Probe Pickup 1.25 . Residual VSWR Less than 1.01 0.0016 gh. to 7.5 GHz less than 1.10 from 7.5 to 8.5 GHz see also Figure 1. Accessories Supplied Storage box, rf...

Standard Earphone Coupler For Field Calibration Of Audiometers

Frequency Response Tdh Earphones

There is much evidence that frequent calibration of audiometers in common use for industrial audiometry is a practical necessity. Cud worth1 has. emphasized the need for maintaining proper calibration of audiometers and has proposed a field calibration and audiometer evaluation system using the sound-level meter. Reports on audiometer performance presented at various hearing and noise symposiums of industrial hygiene and safety organizations have urged periodic calibration. A published study 3...

Gr Precision Adaptors

General Radio Company Slotted Line

The Types 900-QSCJ and -QSCP Adaptors to Type SC are the latest additions to the GR900 series of precision adaptors to military-type connectors. Adaptors previously announced1 include the Types 900-QXJ, -QNP Adaptors to Type X, the Types 900-QBJ. -QBP Adaptors to Type BXC. the Types 900-QTXJ, -QTXP Adaptors to Type TXC, and the Types 900-QCJ, -QCP Adaptors to Type C. The new Types 900-QMMJ and -QMMP Adaptors to OSM BRM are for use with the nonmilitary miniature connectors called group A by...

General Radio Company

Broad Avenue at Linden Rldgefield, New Jersey 076S7 Fort Washington Industrial Park Fort Washington, Pennsylvania 1 9034 Post Office Box 11 SO 11420 Rockvllle Pike Rockville, Maryland 20850 113 East Colonial Drive Orlando, Florida 32S01 Pickard Building, East Molloy Rd. Syracuse, New York 13211 CLEVELAND 5579 Pearl Road Cleveland, Ohio 4412 9 Repair services are available at these offices 6605 West North Avenue Oak Park, Illinois 60302 2GOO Stemmons Freeway, Dallas, Texas 75207 lOOO North...

Stroboslave

Because it is widely used as a tachometer, the conventional stroboscope includes an oscillator and associated electronic circuits necessary to adjust the flashing rate over a wide range. A purchaser who wants only to make stopped-motion observations or photographs, with flashing rate under external control, thus is forced to pay for a capability that is of no use to him. Therein lies the suggestion that a sim- Using the Strobosiave as a diagnostic tool. The reflector has been slipped off so...

The Type A Pulse Amplifier

Tektronix Nuvistor

A new pulse amplifier, the Type 1397-A, has been designed as a companion not only for the Type 1398-A Pulse Generator described in this issue but for the Type 1217-C Unit Pulse Generator and the Type 1395-A Modular Pulse Generator1 as well. The new amplifier increases the relatively low output power available from these instruments to a healthy 50 watts peak. Why have pulse generator and pulse amplifier in separate packages, anyway The separation, a long-standing 1 Gordon R. Partridge. Pulses...

Precision Slotted Line

The slotted line has long been recognized as a fundamental tool for measuring the dielectric properties of materials at high frequencies. In principle, the measuring technique is simple fill a section of coaxial line with dielectric material, determine the propagation constant of the filled section of line from the phase and magnitude of the reflection introduced, as determined by measurement of standing-wave ratio on the slotted line, and calculate the dielectric constant and loss tangent from...

F I ash a new Strobotac electronic stroboscope

Stroboscope Block Diagram

The new Strobotac and optional accessories. Next to the Strobotoc, in leather case, are battery and charger. Above right are battery power cable and extension lamp. The Strobotac itself sits on the high-intensity- The new high-speed Strobotac electronic stroboscope described in this issue extends the speed range for stroboscopic viewing and speed measurement to over 1,000,000 rpm. In addition, the versatility of the stroboscope is enhanced by three optional accessories a rechargeable battery...

Onepercentbandwidth Wave Analyzer

Filter General Radio Company

The Type 1568-A Wave Analyzer with the Type 1 560-P40 Preamplifier connected to the input. When the preamplifier is used, the sensitivity of the analyzer is effectively increased by a factor of 10, giving a maximum full-scale sensitivity of 10 microvolts. Figure 1. The Type 1568-A Wave Analyzer with the Type 1 560-P40 Preamplifier connected to the input. When the preamplifier is used, the sensitivity of the analyzer is effectively increased by a factor of 10, giving a maximum...

Lowdistortion Oscillator

Mhz Sine Oscilator

The Type 1 309-A is the second in our new line of general-purpose variable-capacitance-tuned RC oscillators, recently introduced with the Type 13TG-A Oscillator.1 It continues the modern, all-solid-state design used in the Type 1 308-A and Type 1 3 1 1 -A Audio Oscillators. The continuing need for greater accuracy in electrical measurements, the improvements in sound-recording and reproduction equipment, and the increasingly stringent requirements on communication systems have all lowered the...

Linevoltage Regulators

GR's Type 1 570 series of automatic line-voltage regulators has won wide acceptance since its introduction 1 1 years ago. Now a new series, including 26 different models, makes its debut. Major improvements in the new regulators all-solid-state design, faster response, wider line-voltage ranges, increased power-handling capacity, and availability of all models in 400-cycle versions. Regulated voltage is a necessity wherever voltage-sensitive elements are present, for instance, in many...

MHz Synthesizer Joins The Family

The newest addition to the GR synthesizer line, the T vpk 1 164-A Coherent Decade Frequency Synthesizer Figure 1 , offers greatly expanded frequency coverage, extending well beyond the normal high-frequency, radio-communications bands and including the popular intermediate frequencies. All the features of the low-frequency models12' modular construction, in-line readout, provision for sweeping, continuously adjustable decade CAD , program-mability,3 ac and battery operation have been retained,...