April 1974 Popular Electronics
Table of Contents
Wax nostalgic about and learn from the history of early electronics. See articles
published October 1954 - April 1985. All copyrights are hereby acknowledged.
stood out to me when reading this article on walkie-talkies is a statement made near the end where
the author claims regarding loaded whip antennas, "Transmit losses are many times greater than
receiver losses." The last time I checked, passive antennas are reciprocal devices, so gains or
losses should be the same for transmit and receive. Methinks he either didn't know that, or he meant
something else. My main reason for posting the article is because it pretty much completes the
evolution cycle of walkie-talkies, which started life being called handie-talkies when being
developed during World War II as lightweight, portable 2-way radios that could be deployed in
regions of difficult travel and even carried by paratroopers. Nowadays, most 'serious' handheld transceivers
operate in the 462-467 MHz Family Radio Service (FRS) band, rather than in the 27 MHz Citizens Band as did
early models. The neighborhood where I grew up in the 1960s and 70s had a lot of kids in it, and we
boys did a lot of playing war, cops and robbers, detectives, etc., and often used cheap
walkie-talkies as part of the activities. They were usually so bad that yelling back and forth had
more effective range than the radios.
The Walkie-Talkie in the March 1955
Popular Electronics, A
Self-Contained Handie-Talkie in the June 1944 QST, and
The New Handy-Talkie in
the December 1942 Radio-Craft, and
Walkie-Talkies: Something for Everyone in the
April 1974 Popular Electronics.
Walkie-Talkies: Something for Everyone
By Herb Friedman
Children eagerly look forward to getting a toy walkie-talkie
for Christmas or birthday presents. To their big brothers, those walkie-talkies aren't toys but indispensible
units for things like relaying football plays from the stands to the high-school teams. On the top of
the heap with much better w-t's are the CB'ers involved in REACT and Rescue Team programs where the
compact communicators can prove invaluable over relatively short distances. And outside workers have
adopted the w-t as their principal "no-wire" communication system.
The CB walkie-talkie which began life as a plaything for children has grown into the most popular
communication device of the day. The reason for the popularity of the relatively low cost w-t that operates
on the CB frequencies is due to there being a model almost tailor-made for any applications. Whether
you are looking for a cheap present for a child, a tone-controlled radio tripper device for woodland
photography, or a pocketful of power for search-and-rescue operations, there is a CB w-t to fill your
Low-Cost W-T's. The basic CB walkie-talkie, priced at less than $20, is usually a three- or four-transistor
device with a super-regenerative receiver and a simplified single-frequency, crystal-controlled transmitter.
Its power input is generally stated at a nominal 100 mW, making it license-free (anyone can use it),
although the actual input might be as low as 20 mW, providing a dependable range of only two or three
The superregenerative receiver, noted for a sensitivity almost the equal of a good superheterodyne
receiver, is also noted for its poor selectivity. The less-than-$20 w-t might well receive every signal
frequency on the Citizens Band, regardless of the frequency to which it is tuned. Still, the least expensive
w-t does make a desirable gift for children. But for more serious work, one inevitably must look to
more expensive models.
Moving up the ladder to the $25-$50 range, you will find 100-mW models that are really useful. Featuring
superhet receivers and fully modulated 100-m W transmitters, these w-t's serve a very useful purpose
for short-range work. The transmitter and receiver sections are crystal controlled, and some means is
provided for easily changing crystals.
The receiver generally contains an r-f preamplifier and a 455-kHz i-f amplifier. The i-f section
can provide as much selectivity as can be expected of an inexpensive 5-watt base or mobile CB rig. Models
near the top of the price range often feature an extra stage of i-f amplification, or a ceramic or mechanical
filter for more selectivity to yield performance that approaches that of the better single-conversion
Unlike the superregen w-t's that usually use small 9-volt batteries with average lives of 2-4 hours,
the low-cost superhet w-t uses some type of "penlight" battery, whether it is throw-away or rechargeable
being left up to the user. Depending on the type of battery used, you can expect anywhere from 20 to
50 hours of dependable service before it must be replaced or recharged.
A full 100-mW input power w-t will have a reliable range of about one mile in open country, less
in areas where the terrain is interrupted by hills, buildings, etc. One important advantage of these
units is that they can be used at relatively short range without overloading the receiver; higher powered
models generally overload at close range.
While there is usually no need for multi-frequency capability, it is conceivable that you might have
to communicate with two or more systems operating on different frequencies. The higher-priced 100-mW
models ($35 and up) can give you two or three switch-selectable channels, and they often include some
form of tone signaling system to get the monitor's attention. Another feature you get is a "talk-power"
modulator, with speech clipping or compression similar to that found in 5-watt rigs.
The 5-Watt W-T. When you need long-range communication from a hand-held device, you need lots of
power to get through. Consequently, you will find w-t's with transmitter power inputs ranging from 1
to 5 watts. Power input definitely determines the price you will have to pay for a unit; so, the cost
differences between models usually represent transmitter input power rather than differences in operating
features. (Any w-t with a power input in excess of 100 mW must be operated under a CB license.)
Except for the "stripped" models in the $50 price area, most high-power CB w-t's have features you
would expect to find in quality mobile equipment, starting with a power input jack that permits operation
from an ac-operated power supply. All models have squelch controls, antenna jacks, earphone jacks, and
S/r-f meters that double as battery-condition indicators. Some models have only a battery-condition
The circuits in the high-power units are often identical to those used in higher quality base and
mobile CB rigs. Receiver sensitivity is generally 1 μV or better, while selectivity can be 50 dB
or greater between channels.
Depending on total cost (high-power w-t's ranging from $50 to almost $200), you might have a choice
of three to 23 channels coverage. In most cases, 23-channel models are supplied with all crystals. (You
pay for all whether you need them or not.) One 23-channel model is presently available on a build-up
basis; you purchase only the crys-tals you want as you go along.
For w-t's with less than 23-channel coverage, you add a channel at a time. The usual two crystals,
one for transmit and the other for receive, are required.
As a general rule, the higher power models have some type of "talk power" booster. Though the high-power
w-t's provide extended range, they also prove a decided convenience for short-range work when portability
is a prime requirement. The length of antennas used with CB w-t's can run up to and beyond 4 ft. Hence,
one of the most convenient accessories to have is a loaded whip antenna whose total length is 12 in.
to 18 in. Their short length easily adapts the w-t to belt or shoulder-strap carrying use.
Unfortunately, loaded whips have very low efficiency. When used on a 100-mW unit, the signal might
not make it the length of a city block. (Transmit losses are many times greater than receiver losses.)
But with a loaded whip on a 3- or 5-watt w-t, there is still plenty of power available - more than enough
to cover a large office building, school, stadium, or playground.
A secondary advantage of the loaded whip is that the reduction of output signal power makes the w-t
less prone to frontend "jamming" caused by signal overloads. Of course, the loaded whip cuts down maximum
range. So, when you need maximum range, you can always switch back to the regular whip.
Posted March 29, 2017