Why are you called “hams”?
Nobody knows for sure, but my own theory
is that when ham radio first began, our radios had to be built from scratch,
and the only mode of operation was AM. I
think the word HAM meant “Homemade AM.”
However, HAM can mean Help All Mankind,
because when disaster strikes, we hams are some of the first on the scene. Remember the Great Flood of 1993 along the
Mississippi River? Ham radio operators
spent countless hours relaying messages, hunting for survivors, handling
logistics, and many other things on their own time and at their own expense.
Here in Illinois and throughout the
Midwest, we most often do weather spotting.
When severe weather threatens, trained spotters are sent out into the
countryside around the cities and towns to watch for tornado activity in the
sky and report back via VHF or UHF radio to their “net control station” which
is usually located at the Emergency Operations Center at ESDA headquarters or a
firehouse. The net control operator also
watches the Doppler radar display on the Internet and warns his spotters of
imminent danger in their location.
Helping others in any way we can, is our
“prime directive”. When disasters occur,
often times the phone lines are down and electrical power is knocked out. All normal means of communication are
useless...even cell phones. Our job is
to be constantly on the cutting edge of technology and to be ready to set up
our stations at a disaster site at a moment’s notice. Field Day is our once per year opportunity to
test our equipment and expertise at communicating under difficult conditions
outside our homes. Many ham radio clubs
work closely with local governmental and disaster agencies throughout the year
in planning for disaster management.
How far can you talk?
That depends on the type of radios we use,
and what modes of operation we use. If
we were to use VHF or UHF radios, they would have a range of about 15 miles if
we did not go through a repeater system.
If we use a repeater, our range would be extended to about a 35-mile
radius of the repeater’s location. A
repeater is basically a remote radio site, which takes our transmitted signal
and rebroadcasts it simultaneously at a higher power level. Repeaters are usually located on the tops of
tall buildings, or commercial radio towers.
There are many thousands of repeaters on many different bands all across
the U.S. and the world, which are owned and operated by ham radio clubs and
individuals.
If
we were to use a radio, which operates below 30 MHz, we can talk all around the
world if propagation conditions are good.
We call these bands the High Frequency bands, or HF for short. Back in the early days of ham radio, many
thought that the highest they could possibly go in radio frequencies was 30 MHz
because the technology to do otherwise did not exist at the time. Now, however, things are different. Some ham operators have been experimenting
with frequencies in the 24 GHz
(Gigahertz) range, which is at the high end of the microwave band.
Since the Space Shuttle missions began,
ham radio has been onboard, and we have been able to talk to the astronauts
directly. Many hams have set up stations
at schools around the country and let the school children ask the astronauts
questions. The first astronaut to use
ham radio aboard a shuttle was Owen Garriott, W5LFL.
Some hams with a lot of real estate for
large antennas have been able to bounce VHF radio signals off the Moon and back
to Earth. We call this mode EME, which
stands for Earth-Moon-Earth. The signals
that come back from the moon are quite weak, so a large antenna array is needed
to pick them up. Receiver preamplifiers
are also needed to boost the incoming signals.
Most EME transmissions are done in Morse Code. A lot of transmit power is also needed for
signals to reach the moon. Many
operators use up to the legal limit of 1500 watts.
What is the difference between CB and Ham
Radio?
There is a HUGE difference. CB radios
are cheaply made and poorly designed.
They only put out 4 to 5 watts on AM and 12 watts on SSB. On a good day you might be able to talk
reliably out to 15 miles or so. CB
radios are limited to only 40 frequencies or channels, which is a very tiny chunk
of radio spectrum. In ham radio, we use
entire BANDS of frequencies. For
example, in the 14 MHz band we are allowed to use all frequencies from 14.000
to 14.350 MHz. There are no assigned
“channels”. That is only one band out of
the 10 that we have in the HF frequency spectrum. I haven’t even mentioned the VHF or UHF
bands. So, you can see how much more
versatility we have in ham radio as opposed to CB. Furthermore, we are allowed to experiment
with our equipment to enhance its performance.
That is why we are officially called Amateur Radio Operators. CBers are not allowed to do that. We can even build our own equipment if we
want to, but there are rules and practices to be followed in doing so. That is why we are required to take written
exams.
CB
is not a regulated radio service the way ham radio is. The only time the FCC steps in on CBers is in
cases where repeat offenders cause malicious interference to other radio
services or run amplifiers. Running an
amplifier of any kind on CB is strictly forbidden.
I used to be a CBer back in the early
1970s but I eventually got tired of all the operators interfering with each
other, channel bleed-over and profanity on the air. In 1979 I was introduced to some ham radio
operators in the Gibson City, IL area and they started a ham radio class. On May 20, 1979 I took my ham radio exam and
became a Novice operator. I sold all of
my CB stuff and bought my first ham radio.
You guys still use Morse
Code? I thought that was outdated long
ago!
Much
to the surprise of many, Morse Code or “CW” is still used today, but to a
lesser extent. It is still a reliable method of communication,
and the simplest to use. The fact that
Morse signals are high-pitched audio tones, gives them the ability to be heard
more readily through interference and static.
With electronic filtering devices, we are able to decrease the level of
interference and narrow the bandwidth of our radios so that we hear only the
signals we wish to receive. Other CW
signals which would be audible and within the bandwidth of the radio’s receiver
would be blocked out. You can’t do that
to as great an extent with voice signals without losing a lot of signal
quality.
Receiving Morse Code is like reading
music, only in reverse. With music, you
read the music on the paper, and translate those notes into sound. With Morse Code, you listen to the sound,
then translate that sound to words written on paper. Some operators are so good at CW (Continuous
Wave - another name for Morse Code) that they can copy it in their head at over
40 words per minute, and never have to write anything down!
How do your radio signals go
clear around the world?
Our radio signals are reflected back down
to Earth by bouncing off a layer of ionized air about 50 to 250 miles above the
Earth. It is called the ionosphere
because it is made up of electrically charged oxygen molecules, called
ions. These molecules are charged by the
sun’s “solar wind”. Within the
ionosphere, there are 3 inner layers called the E, F1, and F2 layers.
The E-layer is made up of patches of
ionized air and these float around up there.
That is why we hear signals fade in and out on some of our bands because
these patches of air move and change the angle at which our signals are
reflected back down to the Earth. The
50-54 Mhz band, called 6 meters, is affected by the E-layer. When propagation is favorable on 6 meters,
many hams get on the air and make as many quick contacts as possible before the
conditions fade.
The F1 and F2 layers combine at night to
form one layer, and this enables our signals to go farther distances. These layers do not move around, in patches
like the E-layer does. These layers of
ionosphere basically act as a mirror in reflecting radio waves. Many times our radio waves make many “hops”
across the earth in this manner, and that is how we can communicate with other
hams across the world.
When the sun is highly active, it produces
solar flares. These huge masses of
electromagnetic plasma, x-rays and gama rays produce massive amounts of “solar
wind”, and they can disrupt our communications systems. We hams are especially aware of this, and we
are watchful of the U.S. government’s measurements of this activity. These measurements of geomagnetic activity
are broadcast every hour at 18 minutes past the hour on WWV, the station where
the Atomic Clock is located. Visit their
website: www.nist.gov for more
information. Also read the July 2004
issue of National Geographic for more information on the latest findings on the
sun’s makeup via NASA’s SOHO orbiter.
Another good website to visit is www.solarham.com
.
How
many ham operators are there?
At the last count, there were around 3 million
worldwide, and the numbers are growing.
Japan actually has more hams than the U.S. does. There are
26,206 hams in Illinois and over 800,000 hams in the U.S.
What do you use computers
for in this hobby?
That would be a long list if I told you everything
we use computers for. One of the main
things we use them for is generating digital signals and transmitting them
through our radios. A lot of our
software for digital communications utilizes the computer sound card to
generate and receive digital signals.
The software decodes the signals we hear and displays the text on the
computer monitor. Then when we transmit,
the computer sound card generates the necessary signals, which are put through
the mike jack on the radio. The computer
also puts the radio into “transmit” mode.
In order to properly do this, we use an interface, which lets the
computer control transmit and receive modes.
Another interesting mode, which utilizes our computers, is called
Slow-Scan TV, but it actually has nothing to do with television. Until the personal computer came along,
however, you did need a small TV camera and interfacing equipment to transmit
still
