Helix Building
Encyclopedia
A helix building is a small structure at the base of a longwave
or mediumwave
radio transmitter. Within, there are capacitor
s and coil
s for coupling the signal from the feed cable to the antenna
. Active components such as amplifier
s are usually not housed in a helix building. The interior of the helix building is typically covered with copper or aluminium, in order to control stray radiation.
For safety, helix buildings must be secured, due to the dangerously high voltages which may be present inside.
The helix building, which may be a simple switchbox for small transmitters, is sometimes also the base of a mast radiator
.
Longwave
In radio, longwave refers to parts of radio spectrum with relatively long wavelengths. The term is a historic one dating from the early 20th century, when the radio spectrum was considered to consist of long, medium and short wavelengths...
or mediumwave
Mediumwave
Medium wave is the part of the medium frequency radio band used mainly for AM radio broadcasting. For Europe the MW band ranges from 526.5 kHz to 1606.5 kHz...
radio transmitter. Within, there are capacitor
Capacitor
A capacitor is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric ; for example, one common construction consists of metal foils separated...
s and coil
Inductor
An inductor is a passive two-terminal electrical component used to store energy in a magnetic field. An inductor's ability to store magnetic energy is measured by its inductance, in units of henries...
s for coupling the signal from the feed cable to the antenna
Antenna (radio)
An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...
. Active components such as amplifier
Amplifier
Generally, an amplifier or simply amp, is a device for increasing the power of a signal.In popular use, the term usually describes an electronic amplifier, in which the input "signal" is usually a voltage or a current. In audio applications, amplifiers drive the loudspeakers used in PA systems to...
s are usually not housed in a helix building. The interior of the helix building is typically covered with copper or aluminium, in order to control stray radiation.
For safety, helix buildings must be secured, due to the dangerously high voltages which may be present inside.
The helix building, which may be a simple switchbox for small transmitters, is sometimes also the base of a mast radiator
Mast radiator
A mast radiator is a radio mast or tower in which the whole structure itself functions as an antenna. This design is commonly used for transmitting antennas operating at low frequencies, in the VLF, LF and MF ranges, in particular those used for AM broadcasting. The metal mast is electrically...
.