The maximum size of a cloak without editing the database is 100 hull spaces. At max tech this gives you a 60,000 ton base. While this sounds huge it really is not that big of a pdc. This would give it a active grav signature of 6. In addition a pdc can not mount a cloak device at all. The best you could do would be orbital ships with stealth. With that limit it is unlikely that you could ever actually do something like this. The one exeption I can think of is with a binary or larger system where the components are really far apart and there is no gas giant to give a quick way between the stars. At that point you could have a small planetary population, lots of asteriod miners and maintanence ships ect. Move as much of the support infrastructure off planet and scattered around that star so it doesn't have a big signature. Make sure that there is at least a trace of a bad compound so that the planet does not look good for its habatability index. If possible split up the population between different planets in the same system so that the signature is kept down. One planet for industry, another for research, a third for shipbuilding ect.
Brian
