This is crazy.
What can cause this much noise?
Only one AP running during test. Rural area.
Electrical interference??
btw- this is a good day. Noise sometimes drops into -60's on lower channels.

Amateur radio, non-802.11 AP's running somewhere...

That's my thoughts too.
Closest wireless that I know of is about 10 miles.
Amatuer radio.... is that still popular? lol
I think I'm moving to NV2 on 5.8Ghz. Noise floor looking good on 5.8... for now anyway.

I put up 3 2.4 sectors, thinking I had too many clients on one AP, but not enough non-noisy channels available. Ended up switching all the clients back to original single AP.

Iowa winter is no time to do tower work..brrrr.

you cannot use 2.4GHz antennas and 5.8GHz frequency

Yes, I understand I can't use 2.4 antennae on 5.8Ghz.
Originally I was sectorizing the 2.4 system.
I may try nv2 prior to moving freq's.

Got lucky and found the source of the interference.
Found a customer with a camera system that has been in place for about 3 years but recently started acting up.
Luckily, I know the guy that installed the system and will work with him to resolve the issue.
At the customer site the noise floor was at -48...yikes.
I was switching out an old SmartBridge for a MT device and spotted a suspicious antenna.
Checked the frequency usage with the new MT and BAM -48. Unplugged the radio on the camera system and back up to -99.

Always nice to find someone else has a problem before you spend money on your own equip to fix it.