Aerial amplifier for wide band communication equipment - incorporates low pass filter with capacitor connected to junction between air gap windings

摘要

The aerial amplifier stage between e.g a main station and a subscriber in a wide band communication system can be used for VHF or UHF signals in one direction and signals of a frequency below the VHF region in the other direction. The two connections (11,20) are included in a circulating path which includes an amplifier (17) and also a low pass filter (22). The two coils (23,24) in the filter incorporate air gaps and are designed to eliminate hum resulting from the presence of the signals of different frequencies. The two coils are in series, and to the junction (26) between them is also connected a capacitor (25) forming a low frequency path. Between this junction point and a power supply device (31) is a further LF filter (27).