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1968 Crop of CB, Ham and Communications Antennas
April 1968 Radio-Electronics

April 1968 Radio-Electronics

April 1968 Radio-Electronics Cover - RF Cafe[Table of Contents]

Wax nostalgic about and learn from the history of early electronics. See articles from Radio-Electronics, published 1930-1988. All copyrights hereby acknowledged.

The April 1968 issue of Radio-Electronics magazine had a series of articles on the latest in antenna technology. It included "TV/FM Antennas Are Getting Bigger and Better," "Antenna Rotators," this "1968 Crop of CB, Ham and Communications Antennas," and a couple others, including a build-it-yourself design for UHF television. UHF was a big deal in the day, and was supposed to be the savior of over-the-air broadcast TV, but cable TV came on the scene and cut the legs out from under it, so to speak. As noted by author Noel Penn, it is interesting that the FCC often does not give an EIRP* (effective isotropic radiated power) number for radiated power, only a maximum power level into the antenna. FCC Part 97.313(c) Transmitter power standards does specify EIRP numbers for a few sub-bands, but otherwise uses PEP (peak envelope power). The majority of radio users are technology users with no knowledge of or interest in the science behind the technology. Manufacturers generally make equipment that performs at least acceptably - albeit with some annoyances - as long as all the components are connected properly. Nowadays with the vast majority of personal communications (radio, TV, and Internet) being accomplished via cellphones, very few people will ever need to mess with cables or antennas. Wireless charging eliminates that last remaining physical connection.

*Sometimes ERP is used which is reference to a standard half-wave dipole with a gain of 1.64 dB.

1968 Crop of CB, Ham and Communications Antennas

Cushcraft CB-114D 8-element dual-beam base station CB antenna - RF Cafe

Cushcraft CB-114D 8-element dual-beam base station CB antenna provides 12 dB gain. Front-to-back ratio is 25 dB and VSWR is 1.3 to 1. The dual-beam can be used with any heavy-duty rotator. It has a turning radius of 12 feet.

Hy-Gain CLR2 base station CB antenna  - RF Cafe

Hy-Gain CLR2 base station CB antenna has electrically extended 5/8 wavelength radiator. Effective output power is 6.6 watts and VSWR is less than 1.5 to 1. The CLR2 will survive up to 80-mph winds. It provides an omnidirectional pattern.

Antenna Specialists MC27 is an omni-directional ground-plane CB base antenna - RF Cafe

Antenna Specialists MC27 is an omni-directional ground-plane CB base antenna. Features include 108" solid aluminum heat-treated radials, bent at base clamp to proper angle for 50- ohm match. Antenna has omni-directional pattern.

By Noel Penn

When you think about home TV and FM antennas, you are concerned only with reception. However, in CB, ham or mobile antenna installations the most concern is for transmission.

While transmitter power is limited by the FCC, antenna gain is not. Since an increase in antenna gain is just as effective as an increase in transmitter power, antenna selection is very important.

Cush Craft Squalo is a full-wave. horizontally-polarized, omnidirectional ham antenna - RF Cafe

Cush Craft Squalo is a full-wave. horizontally-polarized, omnidirectional ham antenna. These antennas can easily be stacked vertically to form a complete 5-band "Squalotree" covering the 6-through 40-meter amateur bands. Six-meter Squalos are packaged with suction cup for car mounting, plus a horizontal center support for mast or tower mounting. The Squalo can even be mounted outside a window.

Cush Craft Colinear arrays are well suited to general amateur vhf - RF Cafe

Cush Craft Colinear arrays are well suited to general amateur vhf operation and for amateur TV communications. The 16-element antenna provides a direct match to 300-ohm line, or can be matched to 75-ohm coaxial cable with a balun. Matching stubs are available to match 450-, 200-, 75- or 52-ohm cable directly. Colinear arrays can be stacked for even more gain.

Antenna efficiency can be improved in three ways:

1. Add elements that increase directivity. Base-station antennas, for example, can be made highly directional and rotated to aim at mobile units.

2. Mount the antenna at an optimum height. Follow the antenna manufacturers' instructions. For local contacts, consider line-of-sight obstructions.

3. All antennas in a communications system should be polarized in the same way; either all horizontal or all vertical. Vertical antennas have vertical polarization. Single-element verticals tend to be omnidirectional and put out signals in a horizontal direction, with little or no signal going straight up or straight down.

4. Improve match. You get maximum transfer of power only when the transmitter, the antenna and the transmission line between them are properly matched. The amount of signal put out by the transmitter but not radiated by the antenna is reflected back and forth in the cable and sets up standing waves. Thus, the degree of match is expressed in terms of VSWR (voltage standing-wave ratio). A perfect match would be a VSWR of 1:1, and 1.5:1 is considered the maximum allowable for a good antenna installation.

The partial selection of antennas shown here can only suggest the vast number of various types available.

Today's CB'ers and hams have a tremendous variety of antennas from which to choose. Some antennas can be used for a number of different applications. Many are easily alterable or tunable to frequency. There are antennas for homes, offices, cars, boats and airplanes, with electrical characteristics and mechanical features to suit each. One manufacturer (Mosley) even offers a line of do-it-yourself antenna kits for CB'ers who want to build their own.


Mosley Lancer 23, Hy-Gain Hellcat 1, Antenna Specialists ASM-1, Mosley Channel Cat - RF CafeTo the right from left to right:

Mosley Lancer 23 is a mobile antenna designed for the CB'er who aspires to be a ham or the ham who works the CB channels. For the CB'er the Lancer 23 is equipped with a 10·meter coil. For the amateur, interchangeable coils for 10 to 75 meters are available. The antennas in-corporate a peaking provision for adjustment to any CB channel.

Hy-Gain Hellcat 1 mobile CB antenna has a low-profile look, an etched copper, high-efficiency loading coil in the base, and a spring mounted 17-7 PH stainless steel whip. A new "Claw" mounting device enables antenna to be quickly installed.

Antenna Specialists ASM-1 is a 10-foot CB Marine antenna made of white fiber glass. It has a center-loaded fiber glass whip and chrome-plated brass and stainless-steel fittings. It includes a mounting and lay down kit made of Cycolac, 15' of RG·59/U cable and a connector.

Mosley "Channel Cat" is a CB marine antenna made of stainless steel. Designed to eliminate the need for radials or other difficult to install ground systems. it is effective even on wood and fiberglass boats. The antenna is salt water protected. Loading is through a waterproof coil in the antenna center.

 

 

Posted June 15, 2023

KR Electronics (RF Filters) - RF Cafe

About RF Cafe

Kirt Blattenberger - RF Cafe Webmaster

Copyright:
1996 - 2024

Webmaster:

Kirt Blattenberger,

BSEE | KB3UON

RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

Copyright  1996 - 2026

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.

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