Re: Reception report and 1566kHz 3NE anomalies


Todd
 

Hi Dan,

From where I live in Sydney, 1566 KHz 3NE is 320 miles (515 km). During the winter months around solar noon, 3NE is received via residual E layer skywave. This is due to temporal weakening of the D layer. Normally the D layer blocks incident MW signals from reaching the higher E layer, but during the winter months, especially during low solar activity, sections of the D layer weaken to the point that a degree of signal is not blocked. The term residual means weak and patchy reception. This is why high gain receiving systems are usually required in order to hear daytime skywave signal strengths that are lower than evening strengths. A loop antenna is preferred at my location.

The high end of the MW band is especially sensitive to daytime residual skip. For example, 1503 KHz Melbourne (5 kW) at 450 miles is received via daytime skywave, but less frequently and at lower average signal strength compared to 1566 KHz 3NE. The ionosphere angle of incidence needs to be sufficiently high in order for the signal to penetrate the D layer. A longer distance path corresponds to a lower angle of incidence. This effectively creates a great circle distance limit for daytime skywave.

756 KHz 3RN was received via pure groundwave into Port Phillip Bay in Sth East Melbourne VIC. The frequency (756 KHz) was too low for daytime skywave. However, 1566 KHz 3NE, even though originating from the same general area, was sufficiently high in frequency for daytime skywave.

Regards,

Todd

PS: For Melbourne general area listeners, MW daytime skip targets:

1314, 1431, 1575 Wollongong.
1350 2LF Young.
1368 2GN Goulburn.
1395 5AA Adelaide.
1404 2PK Parkes.
1440 1EA Canberra.
1467 3ML Mildura.
1494 2AY Albury.
1521 2QN Deniliquin.
1539 5TAB Adelaide.

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