I have a 3586B and an 89441. Just above DC-32MHz on the first, with audio demod and super accurate signal level indicator,sensitive to about -120dBm with switchable narrow filters, and a just above DC -10MHz SpecAn on the second. Both are gobs more sensitive below 10KHz, or even 100KHz than any amateur radio transceiver I have ever used. Just because it will display the frequency does not mean it receives there, at least according to my HP and cheap Chinese signal generators.
I have played with a loop antenna some, but this thread has kindled a dormant interest again.?
