I use a 1530 as well, its mounted on a rotator about 2ft above ground level on 
a Barenco 
socket/spike. Works well 80m down to 500khz but being so close to the ground 
its a bit deaf 
above 80m as you would expect. My understanding is that for hf it should me 
mounted high up but 
for lf its better low down near the ground.

A rotator isn't really necessary as the beamwidth is quite broad but where I do 
find it useful is 
nulling out the local qrm, switch modes etc. 

>I can hear NDB's nothing on 500kHz
By NDB I assume you mean the 200/300khz variety so if you can hear them, 500khz 
shouldn't be 
a problem. I recent wspr activity on 500khz I found I could hear everything 
that others were 
hearing...at reduced strength of course, but then I don't have the room for 
"big gun" antennas 
here :-)

73
Trevor  G0KTN