I have a KXTAW848 that is Transmitting a noise similar to a busy signal across the entire AM radio spectrum. It is noticeable up to 2/10 of a mile away from the house and gets so loud at the house that you can’t even hear the radio broadcast. This noise disappears when I shut the phone system down.

Panasonic said that the KXTAW848 is not creating the noise but most likely amplifying it. I have shut down every piece of equipment in the phone closet except the KXTAW848 and the noise persists.

I have a 4 port Hybrid card and a 4 port Proprietary card in it. I have 5 proprietary phones connected to 4 proprietary ports and 1 hybrid port. One hybrid port is for a standard cordless phone and one hybrid port goes to 9 other lines in the house (including one cordless, two analog, and 6 empty phone jacks) I found that as I start unplugging the extensions from these two ports, the volume of the noise decreases a little as each is disconnected until all the lines have been removed and the noise is gone (note: there is no noise with just the 5 proprietary phone connected). The noise shows up again if any line, whether it has a cordless phone or just an empty jack, is connected to the hybrid ports.

The KXTAW848 is grounded to earth ground by way of the water pipe in the basement, and all phone lines are CAT 5.

If anyone has any thoughts on this issue, I would love to hear it.
Thank you.

HAS, A shot in the dark, but I would suggest grounding any unsed pairs of the cables feeding the regular house phones. RF problems can be a nightmare. Good luck.

good call on grounding spare pairs, the wiring can act like an antenna. Check out "mikesandman.com"
for AM filters!!! Good luck!!

That makes sence, but as I said, I get the noise even if a phone is the only thing pluged into one of the hybrid ports. No spare jacks are pluged in. Oh, wait. If the phone is a two wire phone and the hybrid port is four wire, are you talking about that unused pair? Anyway, aside from that, I thought that CAT5 was twisted to prevent it from becomming an antenna. Thanks for the advice.

with all your extensions plugged in and the system powered up see what happens by simply disconnecting all the CO lines to the system and any others that may not be on the system.
Disconnect all the CO lines at the NID.