
09/04/2025
FM listeners to both Classical IPR and IPR News Radio are reporting interference from stations in Wisconsin.
This is due to a phenomenon called tropospheric ducting, which can affect FM signals by strengthening weak signals, interfering with local transmitters and preventing signal return.
During these periods, IPR's FM listeners may hear Wisconsin radio stations that broadcast on the same FM frequencies. The IPR signals may also be weakened significantly.
IPR's broadcast engineer is aware of the interference and monitoring the situation.
Thank you for your patience.
Tropospheric propagation describes electromagnetic propagation in relation to the troposphere. The service area from a VHF or UHF radio transmitter extends to just beyond the optical horizon, at which point signals start to rapidly reduce in strength. Viewers living in such a "deep fringe" reception...