radio

3. in radio amateur use, bi-directional communication on a single frequency
5. passive two-terminal electrical component that stores electrical energy in a magnetic field when electrical current flows through it
8. the direction of a magnetic or electrical field
9. a device used to store an electric charge, consisting of one or more pairs of conductors separated by an insulator
12. an electronic circuit (or computer program in a software-defined radio) that is used to recover the information content from the modulated carrier wave
13. used for measuring the input impedance of antenna systems in radio applications
14. the process of configuring an instrument to provide a result for a sample within an acceptable range
16. the layer of the earth's atmosphere which contains a high concentration of ions and free electrons
19. an arrangement of resistors which reduces the strength of a radio or audio signal
20. one or more cells, in which chemical energy is converted into electricity and used as a source of power
22. an array of dipole antennas mounted in such a manner that every element of each antenna is in an extension, with respect to its long axis, of its counterparts in the other antennas in the array, usually mounted vertically in order to increase overall gain and directivity in the horizontal direction

1. used when it is possible to transmit and receive simultaneously
2. an electronic device that can increase the power of a signal
4. the measurement of a network of triangles in order to determine distance and relative positions of points spread over an area
6. the behaviour of radio waves as they travel from one point to another
7. an aerial consisting of two poles or sections to the radiating element - in its most common it is a half-wavelength long at the frequency of operation
10. used to generate electricity, or one that is used to make chemical reactions possible by applying electricity
11. a horizontal dipole fed at the centre with parallel wire transmission line
14. two concentric conductors separated by an insulator
15. an instruments for converting sound waves into electrical energy
17. an electrical component that limits the flow of electrical current in a circuit
18. a conductive substance with a low melting point used to connect components in a circuit
20. typically an electrical transformer used to connect an unbalanced circuit to a balanced one
21. a specific range of frequencies in the radio frequency spectrum