Homemade panadapter brings a stunt to the old radio


Amateur radio operators can be quite selective about their equipment. Some are old-school purists who would never think of touching a rig containing transistors, and others are perfectly happy with the little software-defined radio (SDR) hooked up to their PC. The vast majority of us, however, fall somewhere in between – we enjoy the classic look of vintage radios as well as the convenience of modern radios. Even better, some of us even like to combine the two by adding a few modern bells and whistles to our favorite “boat anchor”.

[Scott Baker] is one such Ham. He’s only been licensed for a few months now and has already embarked on some big projects, including adding a panadapter to an older Drake R-4B receiver. What is a panadapter you may ask? As [Scott] explains in his excellent writing and video, a panadapter is a circuit that picks up a wideband signal from a radio receiver which usually has a narrowband output. The idea is that instead of just listening to someone’s 4kHz transmission in the 40m band, you can listen to a wide swath of the spectrum, potentially covering hundreds of transmissions, all at the same time.

Well you actually can’t Listen to so many transmissions at once – it would be a clothed mess. What you can to do with that ultra-wide signal, however, is to watch it. If you take an FFT of the signal to place it in the frequency domain (using a spectrum analyzer, or by [Scott]in the case of an SDR), you can see all sorts of different signals in the spectrum. This makes it much easier to find something to listen to – rather than spinning the dial for hours, hoping to stumble upon a transmission, you can simply to see where all the signals of interest are.

This is not the first (or even the twentieth) time that [Scott]The work of has graced our pages, so be sure to check out some of his other amazing projects in our archives!


Comments are closed.