本书的前言：Field effect transistors find application in a wide variety of circuits.
The projects described here include radio frequency amplifiers
and converters, test equipment and receiver aids, tuners,
receivers, mixers and tone controls, as well as various miscellaneous
devices which are useful in the home.
It will be found that in general the actual FET used is not critical,
and many suitable types will perform satisfactorily. The FET
is a low noise, high gain device with many uses, and the dual
gate FET is of particular utility for mixer and other applications.
This book should be found to contain something of particular
interest for every class of enthusiast - short wave-listener, radio
amateur, experimenter, or audio devotee.