Operating instructions

6 ChoosingaHamRadio
Sub-audible: audio frequencies below the usual communication range of 300 – 3000 Hz
Trunking (trunked) systems: VHF/UHF systems used by commercial and government
agencies, sharing a few channels among many users by using computers to control the
radio’s frequencies
UHF: Ultra High Frequency (300 MHz – 3 GHz)
VFO: Variable Frequency Oscillator, refers to a radio’s continuous tuning mechanism
VHF: Very High Frequency (30 MHz – 300 MHz)
Wall wart: light-duty power supply plugged directly into the an ac outlet
Whip: antenna made from a long, thin metal rod
Winlink (Winlink 2000): system for sending and receiving email via Amateur Radio
FRequeNcies aNd modes
If your interest lies primarily in using the local FM repeaters and simplex channels,
information about what frequencies are most used is available from local radio clubs
and newsletters, the local frequency coordinator’s Web site, the ARRL Repeater Direc-
tory (www.arrl.org/catalog), and emcomm teams. Ask about the coverage (range) of the
repeaters, as well.
The most popular VHF/UHF radios for FM voice and data are dual-band, meaning that
they can transmit on both the 2 meter (144-148 MHz) and 70 cm (420-450 MHz) bands.
Higher-end units allow you to monitor several bands at once and listen on one band while
transmitting on the other.
Whether you need the radio to cover the 50 MHz, 220 MHz or 1.2 GHz bands will de-
pend on activity in your area. The first two are often used
by emcomm teams and the last is more likely to be used
in densely populated areas. Cross-band repeater capability
(receiving on one band and retransmitting the signal on the
other band) is a “nice-to-have”, but not commonly needed.
Receiver coverage comes in three flavors. “Ham band
receive” can tune all of the ham bands, plus narrow ranges
above and below the band edges for amateur auxiliary ser-
vices, such as MARS. “Extended receive” includes recep-
tion of selected frequency ranges such as those in Table
2. “Wideband receive” covers a wide range of continuous
frequencies—good for using the radio as a scanner. Be-
ing able to receive commercial broadcasts and non-ham
services is very helpful during emergencies although this
capability may make the receiver more susceptible to over-
load and interference from strong nearby transmitters.
Table2
UsefulNon-AmateurBands
AM Broadcast 550 kHz – 1.8 MHz
Shortwave Broadcast 3 MHz – 25 MHz
Low-band VHF 30 – 50 MHz
FM Broadcast 88 – 108 MHz
Aviation (AM & FM) 118 - 144 MHz
High-band VHF 148 – 174 MHz
Marine 156 – 158 MHz
NOAA Weather 162.4 – 162.55 MHz
Military Aviation 225 – 389 MHz
Government 406 – 420 MHz
UHF 450 – 470 MHz
ARRL0011
3
kHz
30
kHz
300
kHz
3
MHz
30
MHz
300
MHz
3
GHz
30
GHz
300
GHz
radio
Mobile
Phones
UHF
TV
FM
VHF
TV
Shortwave
Low Frequencies High Frequencies
Long Wavelengths Short Wavelengths
AM
audio
VLF LF MF HF
VHF UHF SHF EHF