前言当前在四级办广播、电视的形势下,各地,特别是各大中城市,纷纷要求能同时收到中央、省、市台的各套广播节目。要能收转多套节目,就需要有多部发射机和相应的多副发射天线,同时还要有足够大的天线场地。但是在市区内一般不允许占用很大场地 Preface At present, under the situation of broadcasting and television at four levels, all localities, especially large and medium-sized cities, have asked for the simultaneous reception of radio programs of the central, provincial and municipal levels. To be able to turn multiple sets of programs, you need to have multiple transmitters and the corresponding multiple transmit antennas, but also have a sufficiently large antenna site. However, it is generally not allowed to occupy a large area in urban areas