I thought this might be pertinent:
" . . . Using the ions in the ionnosphere
What role do the ions in the ionosphere play in radio propagation? Most hams know that it's the FREE ELECTRONS that do the real work for us in skywave propagation. Do the ions do anything for us, other than sort of hold the electrons in place?
It depends on the power.
For most amateur radio purposes, the direct interaction between radio waves and ions in the ionosphere is negligible. In addition, the interaction between radio waves and free electrons is surprisingly linear.
However, with enough power, you can wobble ions around enough to have some really interesting interactions....and most of the NON-LINEAR phenomena one observes with facilities like HAARP or the now-decommissioned HIPAS Observatory are due to direct ion-radio wave interaction.
The Luxembourg Effect was the first encounter with the non-linear FREQUENCY MIXING properties of the ionosphere, which only happens if you pump the thing hard enough to accelerate ions directly.
Another fascinating property...one that I was intimately involved with at HIPAS was Simulated Electromagnetic Emission (SEE). As it turns out, if you pump the ionosphere hard enough with a PURE CW carrier, you get an UPPER SIDEBAND carrier emitted. This carrier is just a few tens of Hz above the pump carrier. I helped design some precision direct conversion receivers capable of separating this SEE signal. The physics of SEE is still largely unknown, but it seems to be related to the change of excitation states of ionospheric atoms....very similar to a laser's "population inversion." In any case, it's really cool stuff.
Is there any way Hams can take advantage of direct ion interactions? Possibly. There is increasing evidence that PARAMETRIC AMPLIFICATION can take place, especially on 80 meters. This is where a radio signal can actually ACCUMULATE more power as it travels around an ionospheric duct. Unlike SEE, Parametric Amplification IS a well understood phenomenon....it is the process by which a child (at least a fairly coordinated one!) can pump a swing from a dead start without an outside push.
The importance of being there:
Such "sightings" are obviously rare occurrences. Because of this, it is crucially important that when hams discover something unusual or phenomenal, they need to take careful notes, and not just pass it off as "something odd." This is one of the best reasons to keep an actual log book.....WITH NOTES!
By just being observant hams can indeed still make "contributions to the radio art." as described in FCC Part 97.1.b.
Eric . . ."
From:
http://forums.qrz.com/showthread.php?334487-Using-the-ions-in-the-ionnosphere/page2
op:
