Radio Reception VHF/FM RADIO
The FM radio band consists of frequencies between 87.5-108 MHz and is sometimes referred to as VHF. Good quality stereo reception can be achieved normally by installing an external FM radio aerial. However reception can be impaired by the following problems.
PROBLEM >
Reflected signals
Experienced as distortion especially heard on 's' and 'z' sounds known as sibilance other sounds can also be effected depending on the severity. The problem is caused from signals being reflected from buildings, hills, cranes, scaffolding etc: which arrive at the aerial just after the direct received signal. These delayed signals interfere with the direct signal producing distortion.
What can be done?
PROBLEM >
Weak signals
Weak signals will cause your radio to hiss and subsequently not lock onto stereo.
What can be done?
PROBLEM >
Overloading
Overloading is caused from receiving too strong a signal and is experienced as a twittering sound heard in the background of the channel. It is often apparent if the aerial is sited to a high location, or within close proximity of a FM radio transmitter or when a distribution amplifier is in use and is incorrectly set. Certain radios display a calibrated signal reading to monitor the signal strength, to ensure quality reception the desired signal level for FM radio should measure between 54-74 dB(V micro-volts.
What can be done?