This chapter deals with the operation and circuitry of transistor oscillators. In general, these fall into two categories: the feedback (or vacuum tube equivalent) types, and the negative-resistance (or current multiplying) type.

This chapter deals with the design and operation of the transistor as a low-frequency amplifying device based on the transistor characteristics and limitations discussed in the preceding chapters.

This article contains important miscellaneous considerations, including transistor operation at high frequencies, i-f and r-f amplifiers, limiters, mixers, handling techniques, hybrid parameters, and printed circuits.

The design and servicing of the transistor circuit is more compli-cated than that of the vacuum tube, because transistor input and output circuits are never inherently independent of each other.

This transistor consists of two electrodes (emitter and collector) which which make contact with a germanium pellet, and a third electrode (the base) which is soldered to that pellet.

For many years, the atom was considered to be the smallest particle of matter. It is now known that the atom is composed of still smaller entities called electrons, protons, and neutrons.

Because individual transistors vary tremendously in their initial characteristics, a transistor checker is far more important to transistor circuitry than tube testers are to vacuum-tube circuits.

The experience gained in working with vacuum tubes does not always carry over into the realm of transistors. While transistor circuits can be designed and used based on the principle of analogy to vacuum tubes, yet transistors must be handled in their own way, must be wired, tested, protected and operated in a manner often at complete variance to vacuum-tube techniques. The four chapters that follow describe how to use the new methods and techniques that are required by transistors.

BC817 (datasheet) is used in many projects.

The following note describes some of the features, benefits and applications of the FMMT617 NPN and FMMT717 PNP SOT23 transistors developed by Zetex.