To listen and/or operate on air, radio amateur needs some kind of equipment. Generally, there are two significant parts: receiving and transmitting. To receive signals, we need antennas, antanna feeding cables, impedence matchinng units (also known as antenna tuners) and a receiver. To transmit, we need a signal generator (telepgrah or audio), transmitter, low-pass filters (must) and receiving setup. Setup varies from station to station and may include additional pieces of equipment, such as antenna tuners, power meters, power amplifiers. Combination of receiver and transmitter is known as tranceiver, which mostly holds necessary elements in one case. Some enthusiasts build equipment themselves, some obtain them from shops, second-hand radio amateur related events. This book is about equipment I had experience with, general thoughts, ideas and vision.

Nowadays, transmitter usually is part of transceiver, that is why is chapter mostly dedicated to self-contained transmitter projects, such as radio beacons (telegraph, WSPR and APRS).

A transceiver stands for TRANSmitter/reCEIVER, a combination of receiver and transmitter. Usually, a main element on radio amateur desk ("shack") and a door (or window) on the air.

Antennas are all of sorts. They can be big, very big and strange. Due to the limitations of my locations (QTH), mostly, I build portable antennas.

Power amplifiers are intended.. hmm.. to amplify power of outgoing signal from transmitter to antenna. I would categorize power amplifiears, very broadly into three categories: low power QRP (to 20 W), normal power (to 100-200 W) and high power QRO (all above), sometimes you may see QROO (which stands for very high power and, usually, amount power which is being delivered is not asked, but silently observed from power meter. :D

To be able to emit radio signals, we need energy. That energy, usually, comes from the socket, but not always. This chapter is all about it.