[quote=范工]好像手头现有的dds和pll满足不了这机器的要求吧？这样做的话无异于西装革履下身套个抿档破棉裤！我觉得或者copy原设计或者如ve7ca那样做一个传统意义上的lc振荡器。看他对他的hbr2000的vfo的描述：since low oscillator phase noise is one of the pre-requisites to obtaining a high overall receiver dynamic range, i decided to use an analog vfo and mix the output of the vfo to the required injection frequency with separate crystal oscillators for each of the 9 lowest amateur radio bands. the vfo tuning range is 1 mhz. i can thus tune from the low end of 20 meters up to wwv at 15mhz. as well, a 1 mhz tuning range allows me to cover the lowest 1 mhz of ten meters without having to build another crystal oscillator. the vfo power output level is set to -10 dbm and the crystal oscillators to +7 dbm.[/quote]
讲的有道理，今天花了一些时间在网上找元件，在厦门一家元件网站上找到了几乎所有元件。已经联系报价。
