In his review of the recent Hurst manual approach David has stressed the fact that spectrum analysis is really not the holy grail and an approximation is very workable and provides very similar results. As a matter of fact, spectrum analysis will average results of say a 20 and 24min cycle and create a broader 22min cycle. Just for interest and to help with visual understanding, I will post a set of 1m and 5m Intraday spectrum analysis for EURUSD to highlight variation over time and in particular how an impulse (the mathematical/control engineering term) impacts the spectrum. Note in particular that conventional spectrum analysis will not provide any information on phasing. Hopefully this will assist with cycle understanding.
Sorry people - cannot upload a table so you will have to work with the individual images, download these and then line them up if you like.