I was afraid of this and was hesitant on a standard cable spiltter. One day I'll just buy a proper multicoupler, but not right now.
It's the same 12-20dB isolation in a cable splitter as in a Stridsberg multicoupler, or any other splitter/multicoupler/amplifier.
Just power off the other scanner when you get an interference to see if that is the problem. Activating IFX, if the scanner has that option, can then help. In the 200-300MHz range I have all sorts of interferencies that comes from my sat box, the TV, my computer, all sorts of electronics.
Uniden scanners usually have a 4-6dB difference in signal between different signal bars. 1uV are -107dBm and 2uV are 101dBm
The dBm values for a SDS100's signal strength bars, that pretty much equal most other Uniden scanners, are:
1-115
2-110
3-106
4-101
5-96
If you receive a -105dBm signal it will show 3 bars and if you attenuate 2dB to 107dBm it will show 2 bars. If you receive a -100dBm signal it will show 3 bars and if you attenuate 6dB to -106dBm it would still show 3 bars.
/Ubbe