Wayne! did you try what i suggested in post 11?
Powered splitters do work well, vm engineers will use this type of fix if signals are low.
Powered splitters basically give the same db output that they recieve, so in other words and for talking sake if you input 15db then pretty much that same level is distributed to each line from a powered splitter.
The thing is! and this is where it can get confusing for some people is that powered splitters/amplifiers/ boosters or whatever they want to call them these days are not actually used to boost signals although company's selling such equipment would have you all believe so,that theory is a complete load of bullcrap,,they are simply there for distrubution purposes only and not to boost any signal,and not only that, if your signal is weak then these boosters so to speak will not help you if signals already have issues...its an engineer thing mate...hard to explain.
With terrestrial aerials i use masthead amplifiers where i can actually up the anti and sort poor signals but with sly its not actually possible/vm signals can be oommfed up depending which output on the outside cabinet is used tho..