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
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.