Improving Comcast modem signal

@fuzztone - 

Shooting yourself is preferable to going to the "store" around here.

You sound a bit frustrated with the local service. I assume Comcast is no longer on your Christmas card list!

I hear a lot about the Ground loop issue. What is the problem it can cause and how can I deal with it?

Their latest modem uses an outboard power supply   It’s white and square. Not sure of model name/number

I believe this is what Xfinity supply as standard these days.

Are there any other current models, or is this it?

That (pictured above) is exactly what was installed when I started my xfinity/comcast service a couple months ago. I mis-remembered that it had an internal power supply. My mistake.