CB Radio Amplifier
As you know,
the CB radio is a form of voice communication system which uses
two way communications between people who are spread over a
relatively small distance. This is mostly used by the truck
drivers.
The CB radio
uses some very particular parts of the electromagnetic spectrum
around a frequency of 27 MHz which have been set aside for
public use. It consists of 40 High Frequency (HF) channels on
Amplitude Modulation (AM) and Single Side-Band.
Except for one
particular channel, all other channels are open to use
completely for the general public at no cost. The power of the
transmission modulates according to the fluctuations of the
pressure in the sound waves of the speech. The receiving CB
radio can assess the fluctuations in the radio wave which are
accordingly converted into audio signals of the
speaker.
CB Radio
Amplifiers - Background
For the United
States specifically, one can easily operate a CB radio without
any legal constraints, provided some rules laid down by the
Federal Communications Commission (FCC) are complied with. One
such rule governs the power of the transmitted wave.
There are
strict rules about this which say that the CB station
transmitter power output must not exceed the following values
under any condition: Amplitude Modulation (AM) - 4 watts
carrier power (CP), Single Side-Band (SSB) - 12 watts peak
envelope power (PEP).
Besides this,
the FCC rules also disallows the use of the CB
radio amplifier (technically, the radio frequency
power amplifiers, also called a CB radio linear amplifier, and
any other device which, when can amplify the signal when used
with a radio transmitter as the source of the
signal).
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The only exception to
this is if one has a license in a different
radio service (HAM, etc.) which allows one
to use an external CB radio
amplifier.
The FCC also lays down
strict rules about the 10 meter CB radio
amplifier (used with the HAM radio service)
for certification which ban their operation
on any frequency or frequencies between 24
MHz and 35 MHz (which corresponds to the CB
Radio operation frequency). These FCC rules
basically try to keep a clean signal from a
CB radio transmitter ensuring spectral
purity.
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Despite
these legal issues, however, CB radio linear
amplifiers are relatively accessible in the
United States. CB is the 11 meter band. However,
the 10 meter CB radio amplifier can be used on CBs with
some minor retuning of internal controls of the
amplifier. However, generally these amps produce a lot of
splatter on a lot of the CB channels. The output can be
pretty dirty and the harmonic suppression is quite
poor.
Tokyo Hy-Power makes some
CB radio amplifiers,
though they make the
disclaimer that import of such cb radio amps into the US
is strictly illegal. However, once imported, they may
work well with a HAM. RM Italy is another company dealing
with CB radio amplifier manufacturing.
CB amplifiers can sometimes be found on
eBay. Expect to pay around $100, depending upon the name
brand and features you’re looking
for.
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