许多无线电爱好者都曾有过用彩电高频头制作宽频优质收音头的想法,许多电子刊物也都刊登过这方面的文章和电路。然而,在改制过程中,最困扰大家的是中频制式不符,彩电用的是38MHz中频,带宽65～7MHz,调频收音机则是10.7MHz中频,带宽20KHz。几乎所有的改制者(无论国内国外)都采用二次变频的方法,用NE602,NE605或TDA7021之类的收音集 Many radio enthusiasts have had the idea of ​​making broadband high-quality tuners using color TV tuners, and many electronic journals also publish articles and circuits in this area. However, in the restructuring process, the most troublesome everyone is the IF standard does not match, color TV is 38MHz IF, bandwidth 65 ~ 7MHz, FM radio is 10.7MHz IF, bandwidth 20KHz. Almost all of the reformers (both at home and abroad) have adopted the method of second frequency conversion, with the radio set such as NE602, NE605 or TDA7021