Understanding Band Behaviour

Why Different Bands Behave Differently

Not all radio bands are equal. Each one has its own personality based on how radio waves at that frequency interact with the environment. Understanding this helps you choose the right band for the job.

VHF/UHF — The Local Bands

2 Metres (144 MHz) — Your Main Band

This is where most Foundation activity happens. Signals travel by line of sight with a bit of bending over the horizon. Typical range:

• Handheld radio with rubber duck: 2-10 km to a repeater (depending on terrain)
• Mobile radio with roof-mount antenna: 20-50 km to a repeater
• Base station with outdoor antenna: 50-80+ km to a repeater
• Through a good repeater: You can talk to anyone within the repeater's coverage area — often 100+ km radius from a well-sited hilltop repeater

70 Centimetres (430 MHz)

Similar to 2m but with some differences:

• Slightly less range for the same power (higher frequency = more absorption)
• Smaller antennas (about half the size of 2m antennas)
• More affected by buildings and terrain
• Less crowded — fewer users means less waiting for a repeater

HF — The Long-Distance Bands

HF is where the magic happens. Your signal bounces off the ionosphere and comes back down somewhere far away. But each band has its own character:

80 Metres (3.5 MHz) — The Night Owl

Best at night. During the day, signals get absorbed. At night, the absorbing layer disappears and 80m comes alive. Great for contacts across Australia, and sometimes further. This is the traditional "ragchew" band — long, relaxed conversations. Needs a long antenna (about 40m for a dipole).

40 Metres (7 MHz) — The Workhorse

Works day and night. The most reliable HF band. During the day, good for 500-2000 km. At night, opens up for longer distances. Antenna is about 20m for a dipole — fits most backyards. This is probably the best HF band for a Foundation operator to start with.

15 Metres (21 MHz) — The DX Band

When conditions are good (usually during solar maximum and during the day), 15m can give worldwide contacts. When conditions are poor, it may be completely dead. Smaller antenna needed (~6.7m dipole).

10 Metres (28 MHz) — The Surprise Band

Can be completely dead for months, then suddenly open with incredible worldwide propagation. When it's open, even 10W and a simple antenna can work the world. Very small antenna (~5m dipole). Also has an FM section with repeaters.