The above map can be used as a guide to NVIS ionospheric frequency support and is updated at approximately 40 minutes past the hour.

The satellites listed below have APRS Digipeating capability.

ISS (International Space Station)

• Frequency: 145.825 MHz,  1200bps
• Digipeater Aliases:  ARISS,  RS0ISS-4
• Website

Current Location (You will need to manually refresh this page)

NO-44 (PCSAT)

• Frequency: 145.825 MHz,  1200bps
• Digipeater Aliases:  ARISS,  PCSAT-11
• Website

Current Location (You will need to manually refresh this page)

What is a NET Station?

HF Net stations are used as reference stations when tuning equipment prior to use. Net stations identify themselves with a beacon at 5 minute intervals, to ensure that users have a known reference to tune to.

How do we use them?

Net stations are configured with a special alias of TUNE. This alias acts as a digipeater, but ONLY for the purpose of alignment tests. Whilst a HF setup is being aligned, the user can set a beacon rate much higher than the standard 10 minute interval, and transmit via the TUNE digi. When the frequency alignment is correct, the user will be able to hear the digipeated packet. The highest and lowest frequency that the packet is digipeated at can be split to find the middle of the passband of the net station. At this point, the beacon rate and path must be returned to normal.

Who are the NET stations?

The HF Net stations for each band are:

40m

• Primary NET Station - VK5LY-4
• Secondary Net Station - VK2IO-4

30m

• Primary NET Station – VK3MY-4
• Secondary Net Station - VK4DMI-4

20m

• Primary NET Station - VK2IO-4
• Secondary Net Station -

Popular Modem Offsets

The table below lists the common HF modem/TNC equipment in use, and thier tones.
These have been are categorised into "Groups" for the purpose of carrier frequency selection

APRS HF Frequencies

The table below lists the dial frequency to be used for various groups of HF modem equipment. Both LSB and USB are listed for reference, however in Australia only the column indicated in RED is used. Dial frequencies are usually quoted assuming the 1600/1800 Hz tone pair (Group C).