Beyond FM!
What are the VHF/UHF/Microwave Frequencies?

By Jim Aguirre, W7DHC

I'd like to define what is meant by 'VHF,' 'UHF' and 'microwave' amateur radio frequencies. Here's a generally accepted set of definitions for hams.

The Very High Frequency (VHF) amateur bands are 50-54 MHz (6 M) and 144-148 MHz (2 M). Both offer some extended range communication opportunities along with local communication. Major six-meter openings can provide worldwide communication capability and openings to the East Coast or Alaska are relatively common. Extended two-meter openings can reach out to more than a thousand miles, though 300-400 miles is more likely without extraordinary enhancement. Enhanced propagation will be the subject of another column.

In the Ultra High Frequency (UHF) area, hams have allocations in the 222-225 MHz (1.25 M), 430-450 MHz (70 CM) and 900-928 MHz (33 CM) bands. The 70 CM band is the most used of the three, with the 1.25 M and 33 CM bands having relatively little activity except during contests. Propagation on these bands is shorter than on VHF, but 200-300 mile terrestrial contacts are sometimes possible.

For amateur radio purposes, the true 'microwave' bands begin with the 1240-1300 MHz (23 CM) band. Other commonly used amateur radio microwave allocations include the 2300-2310 MHz and 2390-2450 MHz (13 CM), 3300-3500 MHz (9 CM), 5650-5925 MHz (5 CM) and 10.0-10.5 GHz (3 CM) bands. These bands are relatively short range for the most part; however operation from high-elevation sites can produce some startling results.

There are other amateur radio allocations scattered all the way up to 300 GHz, but they are rarely used except by experimenters. This is the wild, 'final frontier' of amateur radio.

Next, we'll explore what kind of radio equipment is available to get you started on these bands.