2. “ A Rugged, Tunable, Thermally Stable x8 Band Beacon Magnetron”

C. J. ORLEBEKE Raytheon Manufacturing Company

Waltham 54, Massachusetts Packaged magnetrons, until a few years ago, had their

weight reported in pounds. As the demand for miniaturi- zation increased, however, it became desirable to incor- porate ruggedness, tunability, and thermal stability into

scribes the development and achievement of such a tube: a magnetron weighing only a few ounces. This paper de-

an X-band beacon magnetron, cylindrically shaped, which weighs less than six ounces. Particular attention will be paid to those phases of miniaturization which required revision of traditional design approaches.

3. “Production Design of Interdigital-Line Backward-Wave Oscillators”

R. C. HERGENROTHER, R. HARPER, E. SCHEFFLER, and R. McC. UNGER

Raytheon Manufacturing Company Waltham, Massachusetts

This paper gives a brief discussion of the type “0”

tube design problems which are encountered in this type interdigital line backward wave oscillator theory. The new

of backward wave oscillator and some practical solutions of these problems which have made it possible to fabricate these tubes with modern production methods are described.

A description is given of the laminated interdigital line, of the line termination and output transition. A new type of ceramic brazed unitized electron gun designed for these tubes is described.

A description of the structure and electrical characteris- tics of a production S band tube having approximately an octave of voltage tuning will be given as an example of the above work.

4. “Backward Wave Oscillators for the 17 to 41 KMC Band”

J. A. NOLAND AND R. E. LEPIC Sylvania Electric Products, Inc.

Bayside, New York Two K-band backward-wave oscillators developed for

the Evans Signal Laboratory will be described. The speci-

KMC/sec, while that of the other is 26.5 to 41 KMC/sec. fied frequency range of the one oscillator is 17 to 27

The circuit element employed in each case is a unifilar tape helix designed to operate over the desired frequency band within a voltage tuning range of approximately 500 to 2000 volts. The appropriate standard rectangular wave- guide and flange is used for the RF output connector. The power output of the lower frequency tube ranges from

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about 20 to 100 milliwatts while for the higher frequency tube it varies from approximately 4 to 10 milliwatts.

Constructional details will be described, including the type of attenuators employed and the nature of the helix t o rectangular waveguide transition. Typical operating characteristics of each oscillator including tuning curves and power output curves will be presented.

“ A Comparison of Voltage-Tuned Magne- trons with M and 0 Types of Backward Wave Oscillators”

M. WEINSTEIN General Electric Company

Schenectady, New York One of the inherent characteristics of the Voltage Tuned

Magnetron is its capability of being electronically tuned over a wide range in frequency. It is informative to com- pare the VTM with M and 0 backward wave oscillators, which are also capable of wide electronic frequency tuning. The voltagefrequency characteristics, power-frequency characteristics, size, weight, and complexity, will be among the items compared.

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