As was already asked what cable are you using. MOCA runs around a gigahertz. Standard RG6 has near 7 dB loss at 1GHZ per hundred feet. At 250' that's close to 18dB + 3.5 for the splitter. If your router is plugged into the other splitter that about 13 dB loss. So you are looking at ~34 dB loss.
·
·