The Old CATV Equipment Museum
Outside Plant


Pole-mounted outdoor amplikfier housings—
Vacuum Tube - Jerrold Electronics Corp.
Vacuum Tube - Other manufacturers
Solid State
Coffee Can Amplifier

This page illustrates amplifiers used in outside plant.   This amplifier can be characterized as follows:
  • Description: Broadband RF distribution amplifier with adjustable gain or AGC circuitry.

  • Intended Installation: Exterior locations, on utility poles or in pedestals.   When installed on poles, a weatherproof outer housing was usually required.   A pole-mounted installation was featured on the front cover of the March 1964 issue of TV & Communications Magazine.

  • Frequency Range: All amplifiers amplified the VHF Low Band 54-88 MHz (VHF channels 2-6).   Some models were available with extended frequency ranges:
    •  5-88  MHz (cable channels T7-T13 plus 2-6)
    • 54-108 MHz (cable channels 2-6 plus FM)
    • 54-215 MHz (cable channels 2-13 plus FM)

  • RF Ports: One input port and one or more output ports.   Early models were fitted with 300-ohm screw terminals for use with twinlead; later models were fitted with coaxial connectors.   Depending on the manufacturer, several types of coax connectors were used: PL-259, C, F-connectorized-C, or F.

  • Power Switching: None required, although some amplifiers were fitted with chassis-mounted switches for maintenance purposes.   These amplifiers were designed for continuous operation.

  • Housing: Steel or aluminum chassis fitted with a perforated metal cover.   Most models were fitted with flanges or lugs for permanent installation.

    The "coffee-can amplifier" was a notable exception: it was housed in a modified coffee can.

Pole-mounted weather-resistant amplifier cabinet

Some of the earliest cable television systems used broadband distribution amplifiers as line amplifiers, often installed in pole-mounted weather-resistant cabinets.   One such installation was featured on the cover of the March 1964 issue of TV & Communications magazine.

Scan:Lew Chandler
Installation of a Davco Model EQ-2 equipment housing for a line amplifier.   Robert Harmon (left), of Davco, makes the connections to the cable network, while an unidentified lineman from Arkansas Power & Light Company makes the connection to the 120-volt secondary distribution conductors.   Photo: TV & Communications Magazine, March 1964, front cover.   We thank Robert Harmon's family for contributing this issue of the magazine.

Scan:Lew Chandler
Advertisement for Davco Model EQ-2 equipment enclosure.   The stated price is obviously incorrect; the correct price was $39.75.   Source: TV & Communications Magazine, March 1964.

Small Amplifier Housing

Donated by Kaz Majewski, of Centre TV, Wheeling, West Virginia

Photo: Lew Chandler

Medium Amplifier Housing

Donated by Kaz Majewski, of Centre TV, Wheeling West Virginia

Photo: Lew Chandler

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