I should perhaps add that some of the time we were in AM mode which has a rich and mellow tone not heard on any other band.

The bottom limit should be 2Mhz but I think they vary, my mate's 320 only goes down to about 1980khz but mine seems to reach and tune down to about 1900khz (Tuner setting A7).

Last year I was just messing about with a mate checking the bands out and we managed a couple of miles on 160M with our PRC-320 portable military manpacks (which just cover the top 20khz or so of the Top Band). We were using the whip antennas and on the low power setting (2W)!  :o

I was at my QTH which is in a valley surrounded on three sides by chalk downs so maybe it does have some ground penetrating properties?

160M is fairly active here in UK for ragchews in the evening, often there are German and Dutch operators using it as well.

7185khz USB (+2khz for Clansman HF sets) does it for me, if there's general agreement then should we arrange some regional skeds to check how well this works in the real world?