[RFI] 80/160M RFI in neighbor's oven circuitry !

[Bill and Cindy]

HELP !!
 
For 80 and 160 M I have had various verticals over a large radial field, there are
60 X 80' radials. A previous Butternut vertical was thought to be setting off the
neighbor's oven timer, but testing was inconclusive. Then 2 weeks ago I built
a fullsize 66 foot tall 1/4 wave 80M vertical. It must be much more efficient, 
because it is REALLY setting off the neighbor's oven circuitry, the timer beeps
continuously with a key down KW. Their house is 200' from the vertical, and
120' from the edge of the radial field. 
 
They have the usual built in oven/microwave, no wiring is easily accessible.
Where do I start ??
 
Thanks, Bill KO7AA in Tucson