Memorex CP8 TURBO UNIVERSAL REMOTE CONTROL Manual de usuario descargar pdf (Pagina 35)

50 YEARS

of

CAR

ANTENNAS

With the

recent changes

in music

reproduction,

almost

everyone

today

is

into

high -tech car

audio. What

most

don't

realize is that

the car

antenna has

been changing

all

along, too

By Edward Janicki

THE EVOLUTION AND DEVELOPMENT

OF THE AUTO -

mobile

radio antenna is perhaps one of the

most

neglected

success stories in the automotive industry.

Born in the twilight of the last century,

it

evolved

from a

simple

wire wrapped

around

a tree branch, to the

modem

antenna.

In those pioneering

days, the United States

public

was

having a love affair

with both the

automobile

and

radio

broadcasts, so it

was

no surprise that

their marriage did not

take

long

to

arrive. Unfortunately, only a

few of the

techni-

cians that experimented

with car radios had any

formal engi-

neering degrees or training.

Bold men who had been

lured

to

radio

while

in their teens,

they were basically tinkerers

who

developed their skills by the "cut and

try" method.

It is

a

tribute to their ingenuity that some

of their achievements

are

being rediscovered today, proving that

many "new" ideas are

only as new as the people

who conceive them.

The following reviews the evolution of the

car antenna

from

the mid-

1930's

to

the

current day.

The Basics

The car

-radio antenna and its lead -in

cable are the only

links

between

the shielded receiver and

the radio broadcast

station signals. Early on, it became apparent

that the efficien-

cy

of

the

car -radio antenna did

not depend on its length,

and

special

attention

had to be given to

a multitude

of

critical

factors, including impedance

matching,

stray

capacity,

wire

shielding, and

location on the

vehicle.

At first, antennas

were

placed

on the roof, such as a

"clothesline" or

"chicken

wire,"

or

on

the fender

or

win-

dows. Due to their

impracticality, in time they

were replaced

by

various

types

of

under -car antennas,

among them: the

running -board dipole,

metal plate, double and inverted "V,"

triangle, and the "Flexo

-O- Strip." The last

one was intro-

duced by Delco Radio

in 1935 and is

shown in

Fig.

I. Those

types

of undercar antennas disappeared

due to their difficult

installation and susceptibility to

mud,

snow,

and

flying

stones.

An attempt

was made

by the

Ford Motor Company

in 1933

to use the

spare-wheel carrier and the

spare

wheel

as an

Fig. 1- Undercar antennas such

as the one shown,

disappeared due to their difficult

installation and

susceptibility

to mud, snow,

and flying stones.

antenna, but difficulties

in insulating

the

wheel

carrier

from

the rest of the

car, led to an early

demise

of that system (see

Fig. 2).

It

was

obvious,

well into the

1903s, that the

ultimate car

-

antenna system

had yet to be

found. The lack

of such a car-

111111

TO

INSIDE

OF CAR

Fig. 2 -The Ford

Motor

Company

tried

to use the spare

wheel carrier

and the spare

wheel as an antenna,

but

difficulties

in insulating

the wheel carrier

from the rest

of

the car, led

to

an early

demise of

that system.

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