Yes you do. To get MLAT to work, you have to tick the "SBS1 Raw Data" box in IO Settings, even if you don't have an SBS-1 to provide raw data!!
Right Tarbat, read this very carefully. I DO NOT have "SBS1 Raw Data" box in IO Settings checked and I have been a Master User since before it was generally available and mlat some ten to twenty US mil aircraft most days. Some of the features included in later versions of PP were at my suggestion.
Regarding remote mlat, it's quite simple. You can use mlat without a virtual radar, so when you make an mlat request it is sent across the network. If you are a Master User the option "Allow Remote Mlat" is in the Options..I/O settings dialog in the Input section. If this option is checked, then the server will invite PlanePlotter to perform an Mlat on a target that is "Mlattable" but not currently being "Mlatted". The request will only be made if the machine is not in use (no recent user interaction with PlanePlotter), no other Mlat is currently in progress and only if the instance of PP is currently receiving messages from the "positionless" aircraft in question.
The intention is that, with enough users choosing to enable this option, most potentially Mlattable aircraft will start to appear on the charts of Master Users without users themselves having to initiate the Mlat requests.
Finally, I have never found either John Locker or Bev to be biased towards helping only Ground Stations. Of course it is very important that we have maximum GS coverage, but Master Users are important too for reasons I gave above and I have always had the greatest cooperation from and assistance from both men, usually with instant responses - unlike some organisations I could mention.
Tom