I have one and have had it working on HDSDR.
You need to download the extsoft66***.dll file from this site.http://soft66winrad.sourceforge.net/
Then unzip it and put it in the same file as the HDSDR program.
The Soft66LC4 works okay but with HDSDR it will not work below 2.5Mhz.
I just found this out after a few heated e-mails with the designer.
He says the only software that will run it on the lower frequencies is his software.
I never saw this stated anywhere and it makes me a little mad.
I have a softrock that I built myself and it seems to work much better than the
I am glad I only paid the newer $88 price and I am going to sell it.
My opinion is that it indeed does work but is not well supported and does not work well.