I install electrical 10hp motors and drives on gas wells to pump water out to make gas move more freely...  We have over 150 inservice.. I have one land owner that lives 2000 ft away and is having a noise on her AM radio (she is an elder lady). I have installed a line reactor and installed and no help.. Does anyone think that a Ferrite Choke from radio shack would work?  They are cheap and cheap looking. I just dont want to look like a dumba@@ when I go to her house and it does not work.... These drives are set on timers and run when needed in which on this well is alot only off 15 mins out of an hour...Anything else I could try????

You need to work out if the noise is getting into the radio via the mains or the aerial or both. If her radio will work on batteries try that to see what happens. Perhaps also take a battery/mains powered radio with you.

AM can be a real problem. You need a much bigger signal to noise ratio to avoid hearing the noise than on FM. If her radio recieption is poor due to a weak signal this could be very difficult to solve. See if it's on all stations. If just one try retuning that station preset. See if her favorite station also broadcasts on FM.

If it's getting in via the aerial but otherwise her reception is good then the only solution would be to suppress it at source (eg at the pump).

If it's getting in via the mains then a ferrite on her radio or your pump might work but it can be very hit and miss. Typically you need more inductance than a clamp on ferrite will provide at AM frequencies. You might try something like a plug in noise filter..

http://www.ccrane.com/radios/radio-accessories/radio-noise-filter-surge-protecto...

Beware all her neighbours wanting the same treatment.