"A"
"B"
"C",
"D",
"E",
"F",
"G",
"H",
"I",
"J",
"K",
"L",
"M",
"N",
"O",
"P",
"Q",
"R",
"S",
"T",
"U",
"V",
"W",
"X",
"Y",
"Z"
Previous section of 'H' terms and definitions
HEATER. Same as a FILAMENT.
HEAT SHUNT. A device (preferably a clip-on type) used to absorb heat and protect heat-sensitive
components during soldering.
HEAT SINK. A metallic device that dissipates or radiates into the surrounding air the heat that is generated form an integrated circuit or other device. [Heat Sink Manufacturers]
HEIGHT-FINDING RADAR. A radar that provides target altitude, range, and bearing data. [Radar Dictionary]
HELICAL SCANNING. Radar scanning in which the rf beam follows a distorted spiral motion.
HELIX. A spirally wound transmission line used in a traveling-wave tube to delay the forward progress
of the input traveling wave. A large coil of wire. It acts as a coil and is used with variable
inductors for impedance matching of high-power transmitters.
HELIX HOUSE. A building at a transmitter site that contains antenna loading, coupling, and tuning
circuits.
HENRY (H). The electromagnetic unit of inductance or mutual inductance. The inductance of a circuit is 1
henry when a current variation of 1 ampere per second induces 1 volt. In electronics, smaller units are
used, such as the millihenry (mH), which is one-thousandth of a henry (H), and the microhenry (µH)
which is one-millionth of a henry.
Hermetic. Sealed so that an object is gas-tight to a specific rate, normally less than 1 x 10-6 cc/sec of helium.
HERTZ (Hz). A unit of frequency equal to one cycle per second.
HERTZ ANTENNA. A half-wave antenna that is installed some distance above ground and positioned
either vertically or horizontally. Antenna Dictionary
HETERODYNE DETECTION. The use of an a.f. voltage to distinguish between available signals. The
incoming cw signal is mixed with locally generated oscillations to give an a.f. output.
HETERODYNING. The process of mixing two frequencies across a nonlinear impedance. The process of mixing the incoming signal with the local oscillator frequency. This produces the two
fundamentals and the sum and difference frequencies.
HEXADECIMAL. Same as SEXADECIMAL. A number system with a base of sixteen; also pertains to
conditions, choices, or selections that have sixteen possible values or states.
HEXADECIMAL SYSTEM. Pertaining to the number system with a radix of sixteen. It uses the ten
digits of the decimal system and the first six letters of the English alphabet. [Hex Table]
Next set of "H" definitions and terms
