The Alner Hamblin MF02 is a Mains Filter for use with audio and video equipment. Its purpose is to filter mains borne RF interference, and also suppress clicks and spikes that are present on the mains supply, before they enter the audio and video equipment of your system.
RF interference can come from radio stations, motors, computer power supplies, televisions etc., and in fact practically anything that is connected to the mains supply. Clicks and spikes come from local mains interruptions, e.g. turning lights on and off, refrigerator thermostats, central heating time switches, and also lightning strikes. If any of these disturbances are allowed to enter your audio and video equipment, a lifting of the noise floor will result, which will reduce the system dynamic range, and also introduce intermodulation distortion, to the detriment of sound quality.
Modern audio and video products will often use a toroidal mains transformer in the power supply as opposed to the older style laminated iron transformer. While the toroidal transformer is more efficient than the laminated iron type, it is also an excellent pulse transformer, due to its construction and also the difficulty and cost of fitting an electrostatic screen between the primary and secondary windings. This means that your products with toroidal transformers are more likely to suffer from RF Interference.
The MF02 will attenuate frequencies up to 10MHz by more than 60dB, and from 10MHz – 50MHz by more than 45dB.
The above attenuation figures refer to both Common Mode (between Live and Earth or Neutral and Earth), and Differential Mode (between Live and Neutral) interference.
Of particular note, the region up to 2MHz is all-important as this includes AM transmitters, which can be very high power, (several hundred kilowatts radiated power), and is also within the passband of high quality amplifiers and CD/SACD/DVD players.
Supplied with the MF02 is a 1 metre screened mains cable.