HF Conditions
The above image displays the HF Spectrum (1-30Mhz) at the IPS Culgoora Observatory, near Narrabri in northern NSW, Australia.
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 check if it is daylight at Culgoora by looking at the Culgoora Observatory webcam 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 28Mhz, hence the decrease in signal strength above this frequency. The antenna is a 10metre long broadband dipole. This display updates hourly. An example of a solar flare radio burst and fadeout can be viewed
here.
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HF Systems