It worked fine this way a couple years, then a few months ago seemed to garble so bought another tram antenna and was good again until the other day the handheld went out. I did connect the handheld to the coax running to the base one and it got signal, so thinking the short coax to the living room has a bad contact. I can use single coax to each unit if I have to. Is it best to go coax direct to the scanners or use a splitter? I am no expert how these splitters function but thought cable looses and the splitters boost the db loss or something. In the past I only had it connected to a BNC Tee fitting split to both scanners
Ideally each scanner would have it's own antenna.
Splitters do cause loss on each of the output ports. Depending on the design of the splitter and the number of ports it could be anywhere from 3.5 to 7dB loss per port; a two-port splitter will typically be around 3.5db per port (which means only half the amount of signal is getting to each port).
A receiver multicoupler (sort of a glorified splitter) includes a preamp to reduce those losses, but on the other hand is amplifying the noise that comes from the antenna as well as the desired signals unless the preamp is at the antenna, which is a lot more complicated than you probably need or want to get involved with.
Update: Forgot to mention that you might also want to try using less antenna, or try turning on the attenuator. Since you're monitoring a simulcast system it's possible that your scanner is not decoding properly, in which case less signal is better so you can limit your reception to a single tower.