We have a lot of static and loud buzzing on the phone

Right on, Zulu11. Thank you for resolving my problem.

I had the same issue that started on some 3 year old 5.8 GHZ Uniden cordless phones. I moved it from room to room and same buzzing. I found a older Uniden set I had kept in a desk drawer. I swapped out the power transformer (power cord) and it is clear as a bell now.

Dig around in your store of discarded ancient phones (or pick on up at a thrift store), unplug the base unit of your phone system from the phone jack. Then plug in the antique phone that doesn't require a wall transformer to work (one cable to the phone jack is all there should be) and listen if the problem is still there.
If not, then you know who to blame.
*Never* call the 'phone company' with a complaint until you have verified that the problem isn't yours by using your antique phone first.