Radio spectrum scope

File:Elecraft P3.jpg P3 Panadapter]]

File:US Navy RBY-1.jpg. The Panoramic Radio Adapter is the upper part.]]

The radio spectrum scope (also radio panoramic receiver, panoramic adapter, pan receiver, pan adapter, panadapter, panoramic radio spectroscope, panoramoscope, panalyzor and band scope) was invented by Marcel Wallace - and measures and shows the magnitude of an input signal versus frequency within one or more radio bands - e.g. shortwave bands.[https://patents.google.com/patent/US2279151 Panoramic radio receiving system US 2279151 A][http://www.astrosurf.com/luxorion/qsl-ham-history7.htm The History of Amateur Radio] Citat: "...Panoramic reception was created in 1932 by the French engineer and ham Marcel Wallace, F3HM. The Panadaptor is the first spectrum analyzer portraying visually the signals in a selected part of the radio spectrum, making RF signals visible, identifiable my mode...", [https://web.archive.org/web/20200121034629/http://www.astrosurf.com/luxorion/qsl-ham-history7.htm backup] A spectrum scope is normally a lot cheaper than a spectrum analyzer, because the aim is not high quality frequency resolution - nor high quality signal strength measurements.

The spectrum scope use can be to:

• find radio channels quickly of known and unknown signals when receiving.
• find radio amateurs activity quickly e.g. with the intent of communicating with them.

Modern spectrum scopes, like the Elecraft P3, also plot signal frequencies and amplitudes over time, in a rolling format called a waterfall plot.