To what does the term "panadapter" refer? (Physical hardware or software?) How did the term "panadapter" originate as related to radios or electronics?

How is the term "panadapter" different from the spectrum and/or spectrum waterfall display on an expensive receiver/transceiver or an SDR software application? Or is the term a superset of subset of those?


3 Answers 3


A panadapter is a device that adapts the narrow (typically 4kHz) bandwidth of a traditional receiver into a much wider bandwidth, perhaps the entire band. The pan- prefix means all, as in panoramic, pandemic, or Pangaea.

A waterfall display isn't a panadapter, though a panadapter may have a waterfall display built in. A spectrum analyzer can also make a waterfall, but the waterfall isn't the spectrum analyzer.

Since most SDRs have relatively wide bandwidths, they can be used as panadapters. Many panadapters today are based on the RTL SDR design, tuned to the receiver's IF and inserted just prior to the filter.

An SDR used as a standalone receiver would not be a panadapter: there's nothing to adapt.

  • $\begingroup$ Some SDR software I have seen refer to the not-waterfall spectrum display (the one with power instead of time on the vertical axis) as the 'panadapter'. (I agree with you that that's an abuse of terminology. Though on the other hand there does not seem to be any good term at all for that view.) $\endgroup$
    – Kevin Reid AG6YO
    Feb 5, 2017 at 15:09
  • $\begingroup$ @KevinReidAG6YO Fldigi calls it "FFT". GNURadio's GUI blocks call it a "frequency display". I've also seen it called a "spectrogram", though a waterfall is a kind of spectrogram also. $\endgroup$ Feb 5, 2017 at 18:06
  • $\begingroup$ (None of those terms uniquely refers to that type of visualization, though.) I mainly wanted to point out this (mis)usage as it might be part of what the OP saw leading to their question. $\endgroup$
    – Kevin Reid AG6YO
    Feb 5, 2017 at 19:22
  • 1
    $\begingroup$ @PhilFrost-W8II - FFT is just a Fast Fourier Transform. It's one part of how a waterfall is generated. $\endgroup$
    – William
    Feb 6, 2017 at 23:15

Is a panadapter hardware or software?

If you use a hardware spectrum analyzer and a scope, it's hardware.

If the panadapter is based on an SDR, then it requires both the SDR hardware and software.

The difference between a waterfall and a panadapter is that the waterfall shows the spectrum analysis of a range of frequencies over time, which may include just the 3-4KHz audio pass band of the receiver, where the panadapter usually shows at least 12KHz, and more likely at least 1-5MHz (all of one or more bands). Also, the panadapter might only show the instantaneous spectrum analysis, or it could show a wide band waterfall.


There was a U.S. patent issued in 1938 to the PANORAMIC RADIO CORP for a "Panoramic radio receiving system", listing Marcel Wallace, F3HM, as the inventor. In the mid 40's Panoramic Radio introduced a product called the PCA-2 Type T-200 Panadapter. So this product name may be the origination of the term.




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