What is a Citizen Band radio?
A Citizen Band Radio is an AM/FM transceiver. A transceiver
is a radio that can both transmit and receive. The "Band" part of
Citizen Band refers to the "Bandwidth" or frequency range that has
been reserved for use by your average citizen. You do not require a license to
operate a CB which means anyone can pick one up and begin using it.
What do I need to operate on the Citizen
Band?
First of all you will need an actual CB Radio. The CB radio
itself can vary in size, function, and age. You can have a mobile (for your
car), base (in your home), or handheld (in your hand) to choose from. For all
CB's you will need some source of power.
For a mobile this would be a 12 volt
DC connection to your battery, for a Base you would usually have a plug for the
240V converter through a power supply from the home system, and most handhelds
run on batteries. The last thing you need is an Antenna. They vary in size and
function, and there are specific antennas for your car, home and handheld
radios.
What do all the dials on the CB do?
Please note that
not all CB radios will have these controls.
Volume - Usually
the on/off switch and volume of the internal speaker
Squelch - Helps
you to adjust the radio to pick up only strong signals and shuts out the static
that you will hear on most radios.
AM/FM allows you
to switch between the legal AM and FM channels
RF Gain - This
adjustment can be used to adjust the strength of receive that an incoming
signal has on your radio. If someone is right next to you and their radio is
very loud you can turn down the RF gain and their signal will sound softer and
their signal will register lower.
Mic Gain - Used
to adjust the audio level of your voice into the radio.
ANL or NB - Used
to cut out static on the radio
Fine Tune - Usually
found on older radios, used to tune in the signal for clearer receptions
CH9 switch -
Gives you instant access to channel 9, which often is considered as an
emergency channel.
Meter - This
shows you how strong an incoming signal is, or on some radios how strong your
outgoing signal is, what your SWR is, or how your modulation is.
SWR/MOD/DX Switch
- Many radios have self-diagnostics functions. Swr is used to measure the
standing wave ratio (the lower the better), Mod measures your voice modulation
(the higher the better, usually), RF measure the strength of your outgoing
signal (the higher the better).
LSB/AM/USB -
Often nicer radios have SSB or single sideband operation. SSB is a bit
complicated to explain, but basically instead of putting out a signal and have
your voice go for a ride on the signal as in AM, in SSB the voice takes a trip
on its own. For every channel you have Upper and Lower Sideband, but can only
talk on these with a SSB radio. Why use SSB? SSB radios put out up to 12watts
of power instead of the regular 4 watts on AM and the SSB signals tend to go
farther and pick up less static.
Clarifier -
Used for tuning in signals when operating on SSB.
Roger Beep
- Beeps at the end of your transmission to let other stations know you are done
talking.
Local/DX -
Adjust output when transmitting for short or long distance.
Mobile Radios have a distinct advantage over fixed
base radios in that they are smaller (easier to conceal), they have almost the
same features and options as fixed base radios, and they can be used as fixed
base radios simply by connecting them to readily available 12 volt power
supplies. Mobile radios and even fixed base radios can readily be used for
portable operations.
Mobile radios will generally operate in the VHF/UHV1 range
and are best for localized operations. Depending on the gain of the antenna
used in mobile operations the area of coverage for mobile radios can be
anywhere from 1 to 5 miles. Should a survivalist incorporate HF or High
Frequency radio in their communications gear then they can expect to
dramatically expand their area of coverage.
Portable Operations
Are there differences between of mobile radios and portable radios?
The radios themselves are no different when it comes to portable operations. It
is the surroundings that differentiate between fixed base, mobile, and portable
operations.
Portable operations generally use a large and/or more
permanent antenna system than a mobile radio would require. Portable operations
generally are running on either generator or solar energy as the power source
for the communications equipment. The antennas used in portable operation tend
to be either verticals stuck on a pole or a series of tuned wire antennas
strung between structures such as trees.
No matter what radio gear a survivalist chooses they need to
consider the probability that they will be using mobile or portable radio
setups at one time or another.
Fixed base radios will have their usefulness to the
survivalist. Many times communications between like-minded survivalists, or
survivalist camps, are needed and this is where fixed base radios come into
play.
The term "fixed base" is a bit of a misnomer when
referring to modern day 2-way and shortwave communications equipment. The vast
majority of so-called base station radios run off of 12 volt power supplies
making them very adaptable for mobile or portable use.
ADJUST
YOUR SWR on your CB radio
Equipment needed: SWR meter, short jumper coax 3 foot.
Procedure: The SWR meter needs to be placed in
line between the antenna and the CB. Connect the antenna (normally connected to
the back of the CB ) to the connector marked "Antenna" or
"Ant" on your SWR Meter. Connect one end of the short jumper
coax to the "transmit" or "Xmit" on the SWR meter. Connect
the other end of your jumper coax to the CB.
Assuming you have a standard SWR meter the switches should
read as follows: REF or SWR, FWD, and there should be a slide switch marked
"set" or "Adjust". If different consult your meter's owners
manual.
With the radio on the lowest channel (1 on CB) and the SWR
meters switch in the Forward (FWD) position, depress the transmit switch (key
up) located on the microphone. While holding the unit in this transmit mode,
adjust the meter needle to the set position using the Set or Adjust knob on the
meter. As soon as the needle is in alignment with the corresponding mark on the
meter face, flip the switch to the Reference (REF) position. The meter is now
showing your SWR on channel one. Note the value and quickly release the
microphone switch. Record this reading.
Repeat the previous step on channels 19 and 40.
How to read your results: If SWR on channels 1, 19
& 40 is below 2.0, your radio can be operated safely.
If SWR on all channels is above 2.0 but not in the "red
zone" (normally over 3.0), you may be experiencing coaxial cable reaction
(bad quality, wrong length, etc.), insufficient ground plane, or have an
ungrounded antenna mount.
If SWR is in the "red zone" on all channels, you
probably have an electrical short in your coax connectors, or your mounting
stud was installed incorrectly and is shorted. Do not operate your radio until
the problem is found, serious damage can occur to your radio.
If SWR on the lowest channel is higher than it is on the
highest channel, your antenna system appears to be electrically short. Your
antenna length may need to be increased.
If the SWR on channel 40 is greater than that on channel 1,
your antenna is considered to be "LONG" and reduction of physical
height and/or conductor length will correct this situation.
How
does an antenna size affect my CB radio?
If you put 4 watts into a four-foot antenna, you will get
the same power out of that antenna as if you were putting 2 watts into a
102-inch whip.
If you put 4 watts into a 3-foot antenna you will get the
same power out as if you were putting about 1.5 watts into a 102-inch whip.
If you put 4 watts into a 7.5 inch antenna on a hand held
CB, it would put out as much power as a third of a watt into a 102-whip.
If you put 4 watts into a 102-inch whip antenna, it is the
same output as if you put 11 watts into a 3-foot whip.
If you put 4 watts into a 102-inch whip antenna,, it is the
same as if you put 14 watts into a 28-inch antenna.
If you put 4 watts into a 102-inch whip antenna, it is the
same as if you put 54 watts into a 7.5 antenna.
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