Albert's Attic Gallery
This
little gem-a very good five shillings' worth- was first published
in 1954. This was a great age for the electronics constructor.
Consumer goods were very expensive - a TV aerial could cost the
best part of a week's wages, and a television set was a very major
purchase. Large amounts of ex-military electronic materials were
available, left over from the war. The skilled constructor could
start with an oscilloscope or radar screen and build a television
receiver, albeit with a tiny green screen. It was well worth while
to make your own television aerial if you had the resources.
In
the book the word 'television' has the broader meaning of the
word as we know it, but the word 'televisor' is used for the actual
receiver. Although such quaintnesses abound, the first chapter
contains a lucid exposition of basic RF theory that today's student
would find relevant and useful. Later there is a good clear explanation
of transmission line theory, including line reflections and standing
wave ratio. Two types of cable are discussed, balanced twin and
coaxial. The author regarded balanced twin as the norm, with coax
reserved for installations 'where man-made interference is troublesome'.
Aerial elements could be made from copper tube, but for lightness
'duralumin' tube should be used, if it could be obtained. 'The
most difficult part of aerial construction is the formation of
the insulator of the dipole. . .' but one solution was to go to
Woolworth's for an electrical joint box and use that. After the
elements had been fitted the box was filled with beeswax.
The
second edition (1955), included a small section on the new, rather
experimental, band III aerials for ITV. The February 1957 edition
had quite a comprehensive section on Band III, but the author
still obviously regarded frequencies of 200Mc/s (MHz) as alarmingly
high, 'requiring many new techniques'.
An
interesting idea was the 'mains aerial'. In essence, the mains
supply cable was used to pick up the signal. We are warned that
the use of inferior capacitors would be 'risky'.
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