since
Aug.
31,
2011
  |
| Blue line
indicates the signal level of 86.7MHz（frequency of NHK-FM
Akita station, output power:3kW）in a 6 hour period. |
| Red line indicates the signal level of
88.1MHz（frequency of NHK-FM Okinawa station, output
power:1kW and NHK-FM Osaka station, output power:10kW）in
the 6 hour period. |
| comment: Disturbances
appear at around 6 am and 5 pm (times of occurences change
depending on the season) by the radiowave emission from a
power converter of the solar power generation system
installed in the house. |