In article .com,
wrote:
Nope. Be able to display a waterfall graph of a 10 MHz wide portion of
HF so as to identify active transmissions/frequencies.

Cool. My guess, to match your constraints, would be an amplified untuned
loop. (Probably the Wellbrook if you can afford it).

But I wonder, if there's no narrowband selectivity inside the box,
just how sensitive you can be with that bandwidth. (The Laws of
Physics and all that).

Mark Zenier Washington State resident