digital tuning scale - no strings attached

1-08 — elektor january 1980 digital tuning scale no strings attached •• LED display direct — i.e. without any additional transistor buffers. The counter is crystal-controlled. It can "" be programmed to correct for different IF frequencies, so that the same unit can be used for all AM and FM re- ceivers. Furthermore, channel number indication can be selected on the VHF-FM band instead of frequency indication. The system The basic principle is quite straight- forward. The oscillator frequency of the receiver is measured, and the IF fre- The electronics inside radio receivers have changed radically over the years, but tuning scales remain basically the same. The "bent wire on a string" principle is still the most popular. A more "sophisticated" system in the most expensive of modern receivers is digital frequency indication. In this article, an "add-on" scalees quency is subtracted from this to obtain the actual transmitter frequency. As such, the IF frequency is not availab...