余姚无线电厂研制的BT—801型中频扫频仪是一种在国内首批试产,供调幅、调频、收录音机在生产中调试中频放大器或鉴频器的专用测试仪器,它以扫频法和图示法代替逐点测试的老方法,仪器显示配用九时显象管,能直接描出中频特性曲线,图形清 The BT-801 MF Sweeper developed by Yuyao Radio Factory is a kind of special test instrument which is trial-produced in China and is used for debugging IF amplifiers and frequency discriminators in AM, FM and CD recorders. And icon instead of point-by-point test of the old method, the instrument shows nine hours with the CRT, can be directly profile IF curve, clear graphics