HF Conditions

• Current foF2 Plots
• HF Communications Warning
• Ionospheric Summary and Forecast
• Maximum Usable Frequency (MUF) Report

Culgoora spectrograph

Updates: Hourly

The image below displays the HF Spectrum (1-30 Mhz) at the IPS Culgoora Observatory, near Narrabri in northern NSW.

Occupied channels appear as horizontal lines across the display. These are HF channels in use by the general public. Solar flare activity during local daylight hours can cause HF (shortwave) signal strengths to decrease, appearing as a break in the occupied channels in the above display. You can determine if it is daytime at Culgoora by checking the day-night location map on the Culgoora Observatory H-Alpha Image page.

During thunderstorm activity, short vertical strokes of emission can appear on the display.

Antenna gain performance drops above about 28 Mhz, hence the decrease in signal strength above this frequency. The antenna is a 10 metre long broadband dipole.

See an example of a solar flare radio burst and fadeout.