The receiver ought to have a
high resistance to get the best results.
"There," he said, as he laid the telephone receiver on the bench,
"those are the essential things you have to have in order to make
a set of your own. With these things only, it will of course be a
simple set and have a limited range. There are a hundred improvements
of one kind or another that you'll learn about as you get more expert,
and these can be added from time to time. But the special thing I
wanted to prove to you to-day was that it would take only a very small
expenditure of money to get this material together. You see how many
things I've used that any one of you can find about the house, such
as tinfoil, curtain poles, curtain rings, wood for the box, and so on.
The wire needed for your tuning coil and your aerial can be obtained
for less than a dollar. The detector, including the crystal, can be
got for another dollar. An excellent receiver can be bought for two
dollars. A few minor things will be needed at perhaps five or ten
cents each. Altogether the cost of the set can be brought within
five dollars."
This was good news to the boys, many of whom began at once a mental
calculation as to the amount of their pocket money, while others began
to figure on odd jobs that might bring them in the required amount,
in the event that their parents would not supply the money.
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