Active IF Units for the Tranmitter and Receiver

  • Fenderson G.
  • Jansen J.
  • Lee S.

The TD-3 microwave radio system uses heterodyne repeaters in which the IF frequency band is centered at 70 MHz. System equalization, and part of the selectivity is provided at 70 MHz along with over half of the maximum available gain. The IF gain is controlled by an automatic gain control ...

Schottky Barrier Receiver Modulator

  • Abele T.
  • Alberts A.
  • Ren C.
  • Tuchen G.

The receiver modulator of the TD-3 repeater is the first unit in the signal path which uses active devices. Because it is in the signal path, its transmission characteristics must be well behaved, and because it is at the front end of the repeater, its low thermal noise is of ...

Transmitter Modulator and Receiver Shift Modulator

  • Hamori A.
  • Penney P.

In the T D - 3 radio repeater, two upconverters are used: the transmitter modulator and the receiver shift modulator. 1 Although the electrical requirements for these modulators are quite different, the microwave circuit is similar for both. In a T D - 3 microwave transmitter, an FM modulated 70 ...

Microwave Generator

  • Abele T.
  • Leonard D.

The microwave generator is a highly frequency-stable, low-noise source of microwave power which is the local oscillator supply for the T D - 3 microwave transmitters and receivers. It delivers 0.5W output power and is adjustable to any one of 17 different frequencies: 3780, 3800 . . . 4100 MHz.* ...

Active Solid-State Devices

  • Elder H.

Twenty new solid-state devices were developed to meet the TD-3 requirements. The FM terminal transmitter needed a variable capacitor diode (457A) as the active element in the deviator, a very stable voltage regulator diode (446AC), and a transistor oscillator (44A). A family of medium-power varactors (473A, B, and C) was ...

The Traveling-Wave Tube Amplifier for the Microwave Transmitter

  • Bradford C.

Because a traveling-wave tube can provide substantial, stable, microwave power output at high levels of gain with very little noise or distortion, it is used as the transmitting amplifier for the TD-3 radio-relay repeater. The 461A traveling-wave tube, manufactured by the Western Electric Co. (for Bell System use only), has ...


  • Drazy E.
  • Maclean R.
  • Sheehey R.

As described in the first article of this issue, all selectivity required by the microwave transmitter and microwave receiver of the T D - 3 radio system is provided by passive networks. 1 The general plan followed in the design and development of these networks was to: (i) Determine, from ...

3A FM Terminal Transmitter and Receiver

  • Barry J.
  • Gammie J.
  • Lentz N.
  • Salvage R.

As indicated in a companion paper, FM terminals perform the initial and final modulation steps in the T D - 3 microwave radio system. 1 The FM transmitter converts the baseband signal to a frequency modulated signal centered at 70 M H z ; the FM receiver performs the reverse ...

Test Equipment

  • Cooney R.
  • Klisch F.
  • Susen C.

The TD-3 test equipment for routine maintenance and troubleshooting procedures is designed to match the high performance of the TD-3 system and is simple and convenient to operate. The units have good long term stability and may be readily interconnected for testing or self-calibration. This is desirable because much of ...

Power System

  • Jewett W.
  • Mottle S.

The transmission equipment in the TD-3 radio system is designed to be powered from common, --24-volt battery plants. Where voltages other than --24 volts are required, for the traveling-wave tube, the IF circuits, the microwave generator, and the like, they are furnished by power supplies which are powered from the ...

Microwave Radio Equipment and Building Considerations

  • Skrabal R.
  • Word J.

Microwave radio relay stations have existed in the Bell System in several forms since 1950.1 In this time, the equipment and the layouts within the buildings have changed to accommodate the new designs that have been introduced into these systems. The introduction of the T D - 3 repeater bay ...

Contributors to this Issue

Contributors to this Issue

Approximate Mean Waiting Times in Transient GI/G/1 Queues

  • Jagerman D.

This paper presents an approximation method for obtaining the probability the server is busy and the mean waiting time as seen by the nth arriving customer for the GI/G/1 queueing system. Thus, transient behavior is the key issue of the method. The approximation consists of a simultaneous pair of recursion ...