The tuning unit also transforms the resulting antenna input impedance to the nominal transmitter impedance. Although each coil-loaded antenna is manufactured substantially for operation at one frequency only, some frequency adjustment is usually possible depending on the capability of the tuning unit. Coil loaded antennas are usually used for transmitting applications but may also be use for receiving. For proper operation, all land based whip antennas require a good earth connection, usually by means of a ground screen or radial system. All Valcom antennas are provided with a technical manual which includes the technical specifications, assembly instructions and installation procedures for the antenna as well as instructions for any optional accessories ordered.
Most antennas are available with either a side feed or feed-through connection point.
Valcom can recommend and supply appropriate tuning units for use with our antennas. Complete information on the nature of the application is required, such as operating frequency, transmission power, signal type and modulation, etc. It is not advisable to use an external lightning rod system for lightning protection of a Valcom antenna. External structures may adversely affect the operation of the antenna by upsetting the input impedance and absorbing transmitted power which will alter the omnidirectional radiation pattern. If lightning and high static voltage protection is desired, lightning arrestors are available as options for most Valcom antennas.