Phone cuts out. Our house /office phone cuts out unpredicably.We've had Bell in twice to check

Question

Our house /office phone cuts out unpredicably.We've had Bell in twice to check the problem, and the concensus is that the phone we have (a Panasonic KX-TG2564CS 2.4 mhz phone line with one handheld satellite) is not up to the job with power bleeding coming from internet and alarm system. Phone man said the power looks low(30 mhz comes into the house and is reduced to 7.1 by internet and alarm and goes from 7.1 mhz phone unplugged to 1.4-2.1 mhz plugged in. Do we need a new 5.8 mhz phone capable of handling this?