Hey Paul,
Unfortunately, I do not subscribe to "Spectrum Monitor".
But I have gone with the Ultra light "spirit" at times by using pocket MW radios ( maybe "approved" types, maybe not) and something small , like a Select -A Tenna (or other air coil) or an outboard big single bar ferrite antenna, etc .
I had read some years ago about FSL antennas. Some folks absolutely swear by them , others feel the cost / hassle ( even if they DO work well ) isn't worth it and that other approaches are "better".
I have never built one ,so I can't comment one way or another.
The closest thing I built was a small sized "novelty" crystal radio constructed on a mouse trap. #20 cotton was wound over the trap, but it just couldn't QUITE make the inductance needed.So a single ferrite rod was slipped in to make up the difference. Coil ended up sort of like a right triangle.
BUT- the all mouse trap windings only encounter the rod for maybe 1/4 turn or less.The FSL is similar because each winding lays "on" the rod for just a bit ( nothing is wound AROUND a rod).
The RF / EM physics of a 360 degree wound rod vs one that is just laid on a bit would be fascinating to hear about.
Alaska must be an awesome place to Dx when polar conditions allow.
K