Assuming your latest card was much cheaper than the Blackgold card, you could use the saved money to get a single tuner DVB-T2 card (or USB device).
You only need one tuner for the whole HD mux. However, there is no guarentee that there won't be more HD muxes in the future (in fact I hope there will be!)
if I wanted to clear the whole channel scan to completely remove all the channels that have been added. How is this done?
I thought a rescan did it. But what I found was, if I scanned from another transmitter. It would add other channels ( i think local radio channels)
but it did not seem to replace the previous scan, just add new finds to the list.
Be great to be able to delete the lot and start over as a real fresh scan???
In the US for over the air (antenna) ATSC, I use TV Server Config, go to "TV Channels > Channels(nnn)" select the channels I want to delete, and press "delete". I can then do a new Channel Scan.
If you have scheduled recordings the might want to use "export" to save your scheduled recordings and do an "import" when you complete your new channel scan. You probably also need to fix your EPG setup.
Use TVServer Config.... Go into the Channel window...click on the "All Channels" group.... Select the top channel....Scroll down..... Hold the Shift key and select the last channel. This should have selected all the channels..... Now click on Delete.