The Radio Amateurs Hand Book | Page 7

who are
interested in wireless telegraphy and telephony; second, that you would
like to install an apparatus in your home, and third, that it is all new to
you.
Now if you live in a city or town large enough to support an electrical
supply store, there you will find the necessary apparatus on sale, and
someone who can tell you what you want to know about it and how it
works. If you live away from the marts and hives of industry you can
send to various makers of wireless apparatus [Footnote: A list of
makers of wireless apparatus will be found in the Appendix.] for their
catalogues and price-lists and these will give you much useful
information. But in either case it is the better plan for you to know
before you start in to buy an outfit exactly what apparatus you need to
produce the result you have in mind, and this you can gain in easy steps
by reading this book.
Kinds of Wireless Systems.--There are two distinct kinds of wireless
systems and these are: the wireless telegraph system, and the wireless
telephone system. The difference between the wireless telegraph and
the wireless telephone is that the former transmits messages by means
of a telegraph key, and the latter transmits conversation and music by
means of a microphone transmitter. In other words, the same difference
exists between them in this respect as between the Morse telegraph and
the Bell telephone.

Parts of a Wireless System.--Every complete wireless station, whether
telegraph or telephone, consists of three chief separate and distinct parts
and these are: (a) the aerial wire system, or antenna as it is often called,
(b) the transmitter, or sender, and (c) the receiver, or, more properly,
the receptor. The aerial wire is precisely the same for either wireless
telegraphy or wireless telephony. The transmitter of a wireless
telegraph set generally uses a spark gap for setting up the electric
oscillations, while usually for wireless telephony a vacuum tube is
employed for this purpose. The receptor for wireless telegraphy and
telephony is the same and may include either a crystal detector or a
vacuum tube detector, as will be explained presently.
The Easiest Way to Start.--First of all you must obtain a government
license to operate a sending set, but you do not need a license to put up
and use a receiving set, though you are required by law to keep secret
any messages which you may overhear. Since no license is needed for a
receiving set the easiest way to break into the wireless game is to put
up an aerial and hook up a receiving set to it; you can then listen-in and
hear what is going on in the all-pervading ether around you, and you
will soon find enough to make things highly entertaining.
Nearly all the big wireless companies have great stations fitted with
powerful telephone transmitters and at given hours of the day and night
they send out songs by popular singers, dance music by jazz orchestras,
fashion talks by and for the ladies, agricultural reports, government
weather forecasts and other interesting features. Then by simply
shifting the slide on your tuning coil you can often tune-in someone
who is sending Morse, that is, messages in the dot and dash code, or,
perhaps a friend who has a wireless telephone transmitter and is talking.
Of course, if you want to talk back you must have a wireless transmitter,
either telegraphic or telephonic, and this is a much more expensive part
of the apparatus than the receptor, both in its initial cost and in its
operation. A wireless telegraph transmitter is less costly than a wireless
telephone transmitter and it is a very good scheme for you to learn to
send and receive telegraphic messages.
At the present time, however, there are fifteen amateur receiving

stations in the United States to every sending station, so you can see
that the majority of wireless folks care more for listening in to the
broadcasting of news and music than to sending out messages on their
own account. The easiest way to begin wireless, then, is to put up an
aerial and hook up a receiving set to it.
About Aerial Wire Systems.--To the beginner who wants to install a
wireless station the aerial wire system usually looms up as the biggest
obstacle of all, and especially is this true if his house is without a flag
pole, or other elevation from which the aerial wire can be conveniently
suspended.
If you live in the congested part of a big city where there are no yards
and, particularly, if you live in a flat building or an apartment house,
you will have to string your aerial wire on the roof, and to do this you
should