The AM Daytime Preliminary Groundwave Study (formerly "ALLO") lists AM broadcast stations that may be considered by the staff during a daytime groundwave analysis for an AM station proposal. This function does not make actual groundwave calculations. It simply surveys for stations within a fixed distance, depending on the frequency difference:
0 kHz difference: Search radius: 500 km (same frequency)
10 kHz difference: Search radius: 325 km
20 kHz difference: Search radius: 250 km
30 kHz difference: Search radius: 100 km
The Commission's staff may consider additional stations (stations not on this list) as necessary.
For AM stations on frequencies where one is twice the frequency of the other, or where the difference in frequencies is close to the AM band intermediate frequency (455 kHz), refer to 47 CFR Section 73.182(s).
The AM Daytime Preliminary Groundwave Study uses the AM Query to generate and present results.
Questions on ALLO may be directed to Dale Bickel, firstname.lastname@example.org.