Rec.radio.cb Frequently Asked Questions (Part 1: Introduction)
--------------------------------------------------------------
Part 1: Introduction
* New Editor Sought (8/94)
* Table of Contents (9/93)
* Notes about adding questions & answers to this list (2/92)
* Acknowledgements (9/93)
* Notes on "Netiquette" (4/92)
Part 2: Getting Started
* What is CB? (6/92)
* Do I need a license to operate a CB radio? (1/93)
- in the USA (6/92)
- in Canada (2/93)
- in Japan (6/92)
- in Australia (1/93)
- in New Zealand (7/93)
- in the UK (6/92)
- in France (4/93)
- in Germany (6/92)
- in Italy (7/93)
- in Russia (7/93)
- notes for all countries (7/93)
* What are the CB Frequencies? (11/92)
- in the USA (6/92)
- in Canada (6/92)
- in Australia (2/93)
- in New Zealand (7/93)
- in Japan (9/93)
- in countries subscribing to the European CEPT conference (11/92)
- in the UK (6/92)
- in France (11/92)
- in Germany (11/92)
- in Italy (7/93)
- in Russia (7/93)
- in other countries (1/93)
* What are the common brands of CB radios? (7/93)
* What should I consider when choosing a location for my antenna? (7/92)
* Once I hook up my CB and antenna, is the radio ready to use? (2/92)
* What are good antenna characteristics and what are some good antennas? (6/92)
Part 3: Communication
* Which 10-codes are most commonly used? (7/91)
* What are the CB 10-codes? (7/91)
* Where are 10-codes used? (3/92)
* What are some of the more common Q-codes? (3/92)
* What are some tips for communicating with others on the CB? (12/91)
Part 4: Technical Trivia
* What is single sideband? (11/92)
* Do I really get 120 channels on a radio with single sideband? (12/91)
* What are "linear amplifiers" and can I use them with a CB? (7/93)
* Who is "Skip" and why can I hear him all the way across the continent? (7/93)
* How can I reduce engine noise on my mobile CB? (3/92)
* What is GMRS? (6/92)
* Where can I learn more about radio? (3/92)
New Editor Sought
-----------------
With any volunteer effort, contributors come and go. The time has come to
"pass the torch" to another volunteer as editor of the CB FAQ. If you're
interested in taking on the job of FAQ maintainer, you need to have experience
with UseNet and the Internet. You also need access to a Unix site which has
the PERL language (for the AUTO-FAQ software to run.) You don't need to
have a lot of experience with CB radios - though less experience means more
leaning on the Net for experience. Expect to learn a lot about it.
This would be an ideal task for a 2nd- or 3rd-year college student who can
make a multiple-year commitment to volunteer for this.
Notes about adding questions & answers to this list
---------------------------------------------------
We accept suggestions from the rec.radio.cb community. Please consider
the following criteria because we will also use them to determine which
questions to include.
- is it a commonly asked question?
- will its inclusion help reduce usage of net bandwidth?
- how useful is it to CB users in general?
Note that we can't necessarily include every question or every technical detail
because we don't want this FAQ itself to become a net bandwidth hog. We have
to consider the intended audience - this document is intended to help people
get started with CB even if they have no previous technical background with
radio. Therefore, it will not have all the technical discussions that one
might expect in, for example, an amateur radio newsgroup.
If you suggest a question for this list, please include the answer. You'll
get credit for your contribution and you'll speed up the process of getting
the information ready for distribution.
If you feel that your suggestion passes any of the above criteria, send it to
cb-faq@uts.amdahl.com so that it will reach all the FAQ coordinators:
Jean-Marc Bonnaudet Jean-Marc.Bonnaudet@zfe.siemens.de
(Munich, Germany)
Yumeto Funahashi 7K2EUP funa@sramha.sra.co.jp (Saitama, Wakoh, Japan)
Ian Kluft KD6EUI ikluft@thunder.sbay.org (Santa Clara, CA, USA)
Paul W Schleck KD3FU pschleck@gonix.com (Omaha, NE, USA)
English version posted to rec.radio.cb by Ian Kluft
Japanese version posted to fj.rec.ham by Yumeto Funahashi
International readers: when you see something specific to some countries but
the information on your country is missing, please e-mail the details to us if
you have them.
Acknowledgements
----------------
The following people are recognized for their contributions (by e-mail or news)
that were included in the rec.radio.cb FAQ:
Technical Contributors:
Michael Larish KD6CTZ (nomad@ecst.csuchico.edu, Chico, CA, USA)
- helped write the original version of the FAQ
- served as an editor on the project for 3 years
Paul Zander AA6PZ (paulz@hpspdla.spd.hp.com, Palo Alto, CA, USA)
- comments and input on the SWR discussion
Bob Myers KC0EW (myers@fc.hp.com, Fort Collins, CO, USA)
- news article on antenna grounding in mobile installations
Bret Musser (bjm@f.gp.cs.cmu.edu, Pittsburgh, PA, USA)
- news article on reduction of engine noise in mobile installations
Benn Kobb KC5CW (bkobb@access.digex.com, Houston, TX, USA)
- information on the General Mobile Radio Service (GMRS)
Bob Witte KB0CY (bob@col.hp.com, Colorado Springs, CO, USA)
- additional info on GMRS - frequencies, fees, useful contact organization
International/Regulations Contributors:
Neil Robertson (conjgr@lut.ac.uk, Leicestershire, UK)
- original info on CB in the UK
Rob Adams (topfm@darwin.ntu.edu.AU, Darwin, Northern Territory, Australia)
- CB in Australia (operating regulations)
Tetsuo Kobayashi JH8LEF (tetsuo@nttica.ntt.jp, Atsugi-city, Japan)
- CB in Japan
Patrick Wendt (root@chamber.in-berlin.de, Berlin, Germany)
- CB in Germany
Martin Grundy (grundy@rtf.bt.co.uk, Brighton, UK)
- sent faxes of UK CB information sheets
- included summary of CEPT standards and the list of conforming countries
Nick Gibbs (nick@bean.apana.org.au, Stirling, South Australia, Australia)
- CB in Australia (licensing and repeaters, type acceptance)
Jean-Claude Michot (jcmichot@teaser.com, Sevres, France)
- update for CB regulations in France
Jon Clarke (jonc@status.gen.nz, Parnell, Auckland, New Zealand)
- CB in New Zealand
Vassili Leonov (vassili@sbcs.sunysb.edu, Stony Brook, New York, USA)
- CB in Russia
Mike D'Urso (mike%40790.decnet@icnucevx.cnuce.cnr.it, Salerno, Italy)
- CB in Italy
Zbigniew Chamski (Zbigniew.Chamski@irisa.fr, France)
- update for new regulations and tax in France
Notes on "Netiquette"
---------------------
With a growing user community, the rec.radio.cb newsgroup will operate more
efficiently if the following netiquette guidelines are used. Please take them
seriously.
* When posting a followup article, ALWAYS try to minimize the number of lines
of quoted material from the original article.
* As a general rule when you try to determine whether to reply to someone by
e-mail or with a followup article, remember to "praise in public, criticize
in private." It's OK to disagree on the content but be careful not to attack
the person with whom you disagree. Also, be careful with your use of the
word "you" when posting a follow-up article. Many unnecessary flame wars
have started that way.
* Use a descriptive subject. For example, "Antennas" covers a vary large area
so some better choices might be, for example, "Antenna tuning" "Antenna
installation question" or "Antenna theory question". Also, if a discussion
wanders off the original subject, you should modify the subject of your
message to match the new topic. For example:
Subject: Re: co-phasing (was: truckers with 2 antennas)
or, even better:
Subject: Re: co-phasing
* Before answering a question, check if the FAQ adequately answers it or if
someone else already answered it. If you have more to add, make sure to
reference either the FAQ or the related articles.
* If a user posts a question which is directly answered by the FAQ, there is
no need to post an answer - the information is already available on the news-
group. Instead, just send an e-mail message which politely explains where
to find the FAQ. They will probably appreciate it if you include the answer
to their question. (Don't send a "nastygram" - that would just discourage
future participation.)
* Pay attention to the size of your audience - use the "Distribution:" header.
If you leave it blank, your message will go to every civilized country in
the world and occupy disk space in all news systems in all those places. If
that's what you intend, it's fine but be aware that CB is not the same
everywhere. Otherwise, use a distribution for your continent or country as
appropriate for the subject of the message. For example, "na" (North
America) "europe" "us" "uk" "japan" "france" etc. can be used similar to the
following example:
Distribution: usa
or substitute your continent or country. Also, this regional distribution
works for each state of the USA - just use the two-letter postal code for
your state (i.e. ca, ne, co, pa, etc.)
* If you have an item for sale, please limit the distribution area so that,
for example, an article about a radio for sale in New Jersey won't get to
California or Europe. If you wish, you may cross-post your for-sale
article to rec.radio.swap.
* Discussion on any UseNet newsgroup is expected to be within the chartered
subject of the group - there is no such thing as unlimited discussion here.
This newsgroup is chartered for discussion of legal uses of CB radio. Though
some topics are clearly outside these bounds, use some good judgement when
talking about borderline cases. Please take seriously any complaints about
the appropriateness of a subject.
Questions discussed in Part 2: (dates indicate last modification)
* What is CB? (6/92)
* Do I need a license to operate a CB radio? (1/93)
- in the USA (6/92)
- in Canada (2/93)
- in Japan (6/92)
- in Australia (1/93)
- in New Zealand (7/93)
- in the UK (6/92)
- in France (9/93)
- in Germany (6/92)
- in Italy (7/93)
- in Russia (7/93)
- notes for all countries (7/93)
* What are the CB Frequencies? (11/92)
- in the USA (6/92)
- in Canada (6/92)
- in Australia (9/93)
- in New Zealand (7/93)
- in Japan (9/93)
- in countries subscribing to the European CEPT conference (11/92)
- in the UK (6/92)
- in France (11/92)
- in Germany (11/92)
- in Italy (7/93)
- in Russia (7/93)
- in other countries (1/93)
* What are the common brands of CB radios? (7/93)
* What should I consider when choosing a location for my antenna? (7/92)
* Once I hook up my CB and antenna, is the radio ready to use? (2/92)
* What are good antenna characteristics and what are some good antennas? (6/92)
--Rec.radio.cb Frequently-asked Questions-----------------------------Part 2--
* What is CB?
-------------
CB stands for "Citizen's Band" radio. It got that name because its main idea
is to be a kind of radio anyone can use. Depending on the country you live
in, it is either a minimally-regulated or an unregulated set of radio channels
used for short-range (local) communications. Many people use CB radios in
their vehicles, homes or both.
This UseNet newsgroup "rec.radio.cb" is all about CB radio. The FAQ also
covers non-licensed or minimally-regulated radio bands internationally.
Readers can expect to find discussions, questions, and answers about legal
uses of CB and related bands here. There are also other newsgroups for other
radio applications, such as rec.radio.shortwave, rec.radio.broadcasting, and
several subgroups of rec.radio.amateur, for amateur or "ham" radio. Radios
either wanted or for sale are the subject of rec.radio.swap. (Though, an
article about a CB radio for sale should be cross-posted to rec.radio.cb and
rec.radio.swap with a distribution limited to your city, state or region.)
We have to bring up one point because it has been a problem before: any
encouragement of illegal activity is inappropriate because it is outside the
chartered scope of this newsgroup. Such illegal activity includes the use of
illegal equipment or improper operating procedures. (An ongoing effort has
been made to define what is legal in various countries. That depends on reader
input.) However, acceptable (possibly borderline) topics include issues about
legality, how to deal with unruly CB users, and others.
* Do I need a license to operate a CB radio?
--------------------------------------------
The answer to this question depends on the country you reside in. We currently
have information on the USA, Australia, New Zealand, Japan, the UK, France,
Germany, Italy and Russia. Note that all of these are from e-mail reports
contributed by readers. As regulations change, we can only keep up when
people notify us. Please check your local regulations because you are
responsible to know and obey them.
--- in the USA
You are no longer required to have a license to operate a CB radio in the
United States. The FCC (Federal Communications Commission) did at one time
require a Class "D" license for for Citizen's Band which required nothing more
than filling out a form and sending it in to the FCC with the license fee. The
FCC then sent you a call sign which might look like "KPS 2720" or something
similar. During the CB craze in the mid-70's, the FCC decided that the paper-
work burden outweighed the benefits and put CB under blanket authorization.
The FCC permits the use of the following to identify yourself:
1. Your old Class D callsign, if you have one.
2. K, your first and last initials, and your zip code (i.e. KPS 68123)
3. your name (i.e. "Paul")
4. some unique nickname or Handle (i.e. "Cobra", "Rubber Duck", etc.)
A rule change in May 1992 now allows one-way transmissions about highway
conditions on CB. This was intended to allow local authorities to use
unattended audio warnings about road construction or other hazards.
In the USA, there are two additional radio bands besides CB which are intended
for use with minimal regulation by individuals.
1. GMRS, the General Mobile Radio Service, is located in the 460-470 MHz
band. A license is required. More information is included in Part 4.
2. The FCC has recently opened up the 31.0-31.3 GHz microwave band to
licensed users of several fixed and mobile radio services including GMRS.
--- in Canada
No license is required. You may identify yourself by your name or a handle
of your choice.
--- in Japan
No license is required. You may identify yourself by your name or a handle
of your choice.
--- in Australia
Australia's CB regulations are similar to what the USA had before it deregu-
lated CB. A license is required but there is no examination. At last
report, the annual fee was A$18. The government will issue a callsign
such as "VHSA 999" which includes the Australian prefix "VH", a code for the
state (South Australia in this example) and a 3- or 4-numeral suffix.
--- in New Zealand
A license is required in New Zealand. A callsign will be issued with
your license. You must identify yourself by at least your callsign.
Callsigns look like AK1122 ("Auckland 1122") or WN63 ("Wellignton 63".)
There are 16 callsign districts using a 2- to 4-letter code for
the region name and the radio station number. Some callsigns may be issued
for experimental use and will have an "X" after the district name (i.e.
AKX1 "Auckland Experimental 1".)
--- in the UK
A license is required in the UK. For licensing information and/or a set of
"CB information sheets" you may contact the DTI (Department of Trade and
Industry) at the following address: CB Licensing Section, Radiocommunications
Agency, Room 613, Waterloo Bridge House, Waterloo Road, London SE1 8UA, UK.
The telephone number is (+44) 71 215 2171.
The UK will honor licenses from other countries using CEPT-approved radios.
(See the CB Frequencies section below on CEPT for more information.) Your
license may be used under the terms from the country which issued it.
--- in France
As of 1993, France no longer requires a license for you to operate a CB. But
there is a 296.50FF tax on CB radios which is close to the cost of the old
license. The main difference is that the old license was good for 5 years.
Now you will pay the tax every time you buy a radio.
Like most (or possibly all) of Europe, France does not give you a callsign.
So you may identify yourself by your name or a handle of your choice.
France will honor licenses from other countries using CEPT-approved radios.
Your license may be used under the terms from the country which issued it.
--- in Germany
A license is required whether you plan to use FM or both AM and FM. The
"agreement card" costs more if your radio also has AM. You may identify
yourself by your name or a handle of your choice.
Germany will honor licenses from other countries using CEPT-approved radios.
Your license may be used under the terms from the country which issued it.
--- in Italy
A license is required to operate a CB in Italy. Licenses may be obtained
from Ministero PP.TT. You will need to provide them with your CB's model,
serial number, and certification number. They will also want to know
your "handle" (if you go by a fictitious name on the radio) and whether
you want your license to apply to other members of your family. The total
cost is (equivalent to) US$50 plus $10 per year. You must notify the PP.TT
if you sell your radio or buy a new one because the license applies to a
person and a radio. Our reporter in Italy says it takes about 2-3 months
for the license to arrive. It is valid for 10 years.
--- in Russia
A license is required. You must identify yourself by the callsign that
is issued with your license. Callsigns look like "3A4157".
--- notes for all countries
There are rules and regulations that must be complied with while using CB, no
matter which country you live in. If you don't have a list of those rules
(which most likely were included with your CB), you will probably find them at
any store that sells CB radios. If your government issues a callsign to you,
you must identify yourself at least with that callsign.
* What are the CB Frequencies?
------------------------------
The answer to this question depends on the country you reside in. We currently
have information on Australia, Austria, Belgium, Canada, Cyprus, Denmark,
Finland, France, Germany, Luxembourg, Italy, Japan, the Netherlands, New Zealand,
Portugal, Norway, Russia, Sweden, the UK, the USA, and Vatican City.
--- in the USA
Legal CB transmitters use the operator's choice of AM (amplitude modulation)
(with 4 watts maximum power) or single sideband (with 12 watts maximum power)
on the following frequencies.
frequencies (MHz) modulation description
26.965 - 27.405 AM/SSB Citizen's Band (CB)
40 channels, max power 4W AM, 12W SSB
1=26.965 11=27.085 21=27.215 31=27.315
2=26.975 12=27.105 22=27.225 32=27.325
3=26.985 13=27.115 23=27.255* 33=27.335
4=27.005 14=27.125 24=27.235* 34=27.345
5=27.015 15=27.135 25=27.245* 35=27.355
6=27.025 16=27.155 26=27.265 36=27.365
7=27.035 17=27.165 27=27.275 37=27.375
8=27.055 18=27.175 28=27.285 38=27.385
9=27.065 19=27.185 29=27.295 39=27.395
10=27.075 20=27.205 30=27.305 40=27.405
460 - 470 FM General Mobile Radio Service (GMRS)
license required, see Part 4
31.0-31.3 GHz any mode microwave band now open for individuals
to use, requires GMRS license, see Part 4
* Channels 23-25 are not in ascending order due to historical reasons. CB
started with only 23 channels. Later, 24 and 25 filled a gap between 22
and 23 and 26-40 were added in ascending order.
Special-use channels:
9 - emergency, monitored in some areas by "REACT", a volunteer group
coordinated by the local Sheriff's office (not in all areas)
17 - unofficial "trucker's" channel (California & western states.)
19 - official "trucker's" channel for traffic and speed trap advisories
30-40 - Often are used for single sideband (SSB) activity
Note that US regulations disallow "DX" long-distance communications (over 150
miles in this case) with CB. However, directional antennas may be used to
enhance communications within the legal range.
--- in Canada
The CB frequencies, modulation, and power limits are the same as the 26-27 MHz
CB band in the USA. Radios must be type accepted for use in Canada.
--- in Australia
Australia has 2 bands for CB. The use of AM or FM depends on the band.
frequencies (MHz) modulation description
26.965 - 27.405 AM/SSB 40 channels, same frequencies as USA
max power: 4W AM, 12W SSB (same as USA)
476.500 - 477.475 FM 40 channels, .025 MHz (25 kHz) spacing
max power: 5W
We've been told there are "no antenna restrictions" though you'll probably
need to double-check with local regulations if you're thinking of putting
up a tower.
Radios for the Australian 26MHz band are essentially the same as radios made
for the USA. However, all CB radios used in Australia (either band) must be
type accepted by the Department of Transport and Communications (DOTAC).
The following AM/SSB band frequencies have special uses in Australia:
Channel 8 Road channel (truckers)
Channel 9 Emergency (same as USA)
Channel 11 AM calling
Channel 16/LSB SSB calling, also used for DX (distance)
Channel 35/LSB unofficial additional SSB calling, also for DX
A unique feature of Australia's 476-477 MHz band is that repeaters are allowed.
Inputs are on Channels 31-38 and outputs are on Channels 1-8. A repeater must
use the proper channel pair, i.e. 1/31 to 8/38. The maximum power output for
a repeater is 21W input. Note: as with repeaters on other bands, do not begin
to operate one without obtaining and fully understanding the applicable
regulations. Additional information about the technical aspects repeater
operation is available from amateur (Ham) radio sources such as the ARRL
Handbook.
--- in New Zealand
The CB frequencies, modulation, and power limits are the same as the 26-27 MHz
CB band in the USA and Australia.
The following frequencies have special uses in New Zealand:
Channel 5 European call (USB)
Channel 11 truckers' channel (AM)
Channel 15 AM calling
Channel 35 SSB calling
--- in Japan
Japan has 3 radio bands that do not require licenses. Two of them are limited
to extremely short-range use because of low power limits. The other, with
maximum power output of 5 watts, is more like CB as it is known in North
America, Europe and Australia.
frequencies (MHz) modulation description
26.968 - 27.144 AM (no SSB) "Citizen's Radio" maximum power 0.5W
channels 1-8 on 26.968, 26.967, 27.040,
27.080, 27.088, 27.112, 27.120, and 27.144.
Other channels in between these are assigned
to fishing vessels (with 1W max power).
421.8125 - 422.300 FM "Specific Low Power Radio", also known as
"UHF CB" maximum power 0.01W (10mW)
newly-authorized in 1989, mostly used for
handy-talkies and ski patrols
9 duplex channels with 12.5kHz spacing
421.8125/440.2625 ... 421.9125/440.3625
9 simplex channels with 12.5 kHz spacing
422.2000 ... 422.3000
Note: other frequencies in this band are
allocated for business use
903.0125-904.9875 FM "Personal Radio" maximum power 5W
158 channels with 12.5 kHz spacing
External antennas are permitted.
Radios must be equipped with a control ROM
for automatic ID.
As in Europe, made-for-the-USA CB radios are illegal in Japan. There have
been cases where such radios have caused interference with maritime emergency
traffic.
--- in countries subscribing to the European CEPT conference
The following countries have implemented the CEPT (Conference of European
Postal and Telecommunications administrations) recommendations T/R 20-02 and
T/R 20-07 for CB radios:
Austria, Belgium, Cyprus (see Note 1), Denmark (see Note 2), Finland,
France, Germany, Luxembourg, Netherlands, Portugal (see Note 2), Norway
(see Note 2), Sweden, United Kingdom, and Vatican City.
Notes:
1) as of last report, confirmation was pending in Cyprus
2) special markings are required on the radios so, for example, UK radios
marked "CEPT PR 27 GB" are legal but ones marked "PR 27 GB" are not.
Radios from other countries may also be similarly affected.
CEPT approval is significant because, with the exceptions listed above, CEPT-
approved CBs from any one of the countries listed above can be used in any
other on the list.
frequencies (MHz) modulation description
26.965 - 27.405 FM 40 channels, same frequencies as USA
4W max power
If you travel to another CEPT-conforming country, you may use your CB under
the terms of your license from your own country. Be aware that only FM is
CEPT-approved so AM and SSB may not be legal to use once you cross the border.
Important note: CEPT-approved CB radios are not legal in the USA and made-for-
the-USA CB radios are not legal anywhere in Europe. The difference is because
CEPT radios use FM and American radios use AM or SSB. There are no agreements
allowing a radio which is type-accepted in North America to be used in Europe
or vice versa.
Channel 19 appears to be the calling channel in most CEPT-conforming countries.
When exceptions are known, they are listed specifically for the country.
--- in the UK
The UK has 3 bands for CB as follows:
frequencies (MHz) modulation description
26.965 - 27.405 FM 40 channels, same frequencies as CEPT & USA
4W max power
radios using this band are marked "PR 27 GB"
or "CEPT PR 27 GB" and are CEPT-approved
27.6 - 27.99 FM 40 channels, 0.01 MHz (10 kHz) spacing
4W max power
radios using this band are marked "27/81-UK"
and are only legal in the UK
934.0125-934.9625 FM 20 channels, 0.05 MHz (50 kHz) spacing
4W max power
radios using this band are marked
"CB 934/81" and are only legal in the UK,
no new radios of this type are being made
but existing equipment may continue to be
used legally
Antennas must be omnidirectional - beams and yagis are prohibited. Antennas
must stand vertically, no higher than 1.65m (not including ground plane.)
AM and FM are not compatible so a US-legal CB cannot communicate with any
UK-legal CB even though they may use the same frequencies. And each is illegal
on the others' soil so this only prevents use of atmospheric skip between them.
(See Part 4.)
--- in France
France uses the same frequencies (in 40 channels) as CEPT and the USA. AM, FM
and SSB are permitted. The only legal CB radios in France are those which are
approved by France Telecom or visiting CEPT-approved radios.
frequencies (MHz) modulation description
26.965 - 27.405 AM/SSB/FM 40 channels, same frequencies as USA
max power: 1W AM, 4W SSB, 4W FM
Channel 9 AM used to be for emergencies but was deregulated because no one
monitored it for that purpose. Channel 19 AM is the calling channel (used to
establish contact then move to another channel.) Channel 11 FM is used for
DX/skip long-distance contacts. Channel 27 AM is sometimes used as a calling
channel for base stations (at home.) AM is the most commonly-used modulation
method in France.
When traveling outside France, remember that most countries in the CEPT
conference do not permit the use of AM or SSB. France has adopted the CEPT
rules for CB in Europe - see below for more information.
--- in Germany
Germany also uses the same frequencies as CEPT and the USA. AM and FM are the
only legal modes of modulation. (SSB is not allowed.) AM is only allowed on
some channels.
frequencies (MHz) modulation description
26.965 - 27.405 AM/FM 40 channels, same frequencies as USA
max power: 1W AM and 4W FM
AM is allowed on Channels 4-15
FM is allowed on all 40 channels
SSB is not permitted
All signals must have vertical polarity.
Channel 4 FM is the calling channel. FM is the more commonly-used modulation
method in Germany.
Notes: to meet the vertical polarity requirement, antennas must stand vert-
ically. Also, tone-call transceivers are allowed so you can use touch tones
to call someone if they are within receiving range and have a radio that will
recognize the tones.
When traveling outside Germany, remember that most countries in the CEPT
conference do not permit the use of AM. Germany has adopted the CEPT rules
for CB in Europe - see below for more information.
--- in Italy
Italy also uses the same frequencies as CEPT and the USA. AM, FM, and SSB
are permitted.
frequencies (MHz) modulation description
26.965 - 27.405 AM/FM/SSB 40 channels, same frequencies as USA
max power: 4W AM/FM/SSB
Directional antennas are not permitted
Selective call devices (i.e. tone
encoders or tone squelch) are not
permitted
Channel 9 is recommended as an emergency channel. Truckers often use
Channel 5 on AM. It has been reported that Q-codes are popular in Italy.
Our reporters in both Italy and Germany have said that many Italian CB'ers
can be heard using linear amplifiers even though they are illegal.
--- in Russia
CB radios in Russia use the same frequencies as the USA and CEPT (European)
countries. AM and FM are both permitted. The maximum transmit power is
5 watts. Our reporter from Russia says there is no restriction on the
distance of communications so, technically, use of skip (see Part 4) can be
assumed to be legal.
Because both AM and FM are legal, Russian CB radios can communicate with
European radios (in FM) and with North American or Australian radios (in AM.)
--- in other countries
This is the "grab bag" section. We have incomplete information on these
countries but we'll tell you what we've heard. We'll add more information as
people send it to us. (If you know more, please tell us!)
* Switzerland uses FM on the same frequencies as CEPT but CBs do not appear to
be very common there.
* Channel 19 is the calling channel in Poland. Some probably-outdated info
said that this was also the case in Czechoslovakia but that may not
necessarily be true under the new governments of the Czech Republic and
Slovakia.
* The calling channels in Austria are 4 AM and 9 AM.
* From California, we can hear a lot of CB activity in Mexico via skip but no
one has provided us with any details yet. However, we know that Mexico uses
AM on the same frequencies as the USA's 27 Mhz CB band.
In every country we know of where CB is legal, radios must be type-accepted,
meaning they must have been manufactured specifically for use with one or more
country's regulations. They must be unmodified and properly marked for use in
that country. The exception is CEPT-approved radios, which may be used in any
country which has implemented the conference's recommendations.
* What are the common brands of CB radios?
------------------------------------------
Some of the more common brands that you will find out in the USA market are as
follows: Uniden, Cobra, Midland, Realistic (Radio Shack), Archer (Radio Shack)
and others. Made-for-the-USA CB radios are also legal in Canada and Australia
though they must be properly labeled ("type accepted") for sale and use in
those countries.
In France some common brands of radios are President and Midland. These are
somewhat similar to Germany but the President brand is known as "Stabo" there.
In Italy, Midland, Lafayette, and President are among the popular brand names.
We currently don't have any corresponding information for other countries. Note
that radios must be marked properly for sale in your country, even in countries
using American or CEPT (European) radios.
* What should I consider when choosing a location for my antenna?
-----------------------------------------------------------------
The answer to this question differs greatly between base and mobile installa-
tions. Each will be answered separately.
In mobile installations, things to consider are whether you're willing to
drill holes or use a magnet mount, gutter mount, trunk mount, or a bumper
mount. If you say "no" to all of those (which would probably mean you have a
very nice car) your list of options is pretty short - use a handheld with a
rubber duck antenna.
Otherwise, you can start making choices with the following things in mind:
1) the closer your antenna is to the top & center of the vehicle, the better.
So the roof is better than the rain gutter or trunk and all of those are far
better than the bumper. But they'll all work.
2) a drilled/permanent mount is better than a magnet mount in the same loca-
tion. (This is so that the antenna gets a better "ground plane".) If you use
a magnet mount, run your coax feed line through the door or hatch that gets
the least use and then leave it alone. Don't use any path where the coax
would get pinched.
For base installations (i.e. at home) the best places are "as high as you can"
within legal limits. The roof is normally fine. If you're in an apartment
complex, you may be limited to a balcony but ask the manager - they may just
want you to keep it "invisible." (Check your national and local regulations.
In the USA, the FCC regulations limit CB antennas to 60 feet above ground
level or maybe shorter if you live close to an airport - one foot high for
every hundred feet from the nearest runway.)
Base station antennas should have a good ground in case of lightning. (In the
rare event of a lightning strike, this can mean the difference between burning
down the building or just the radio.) Most cold water pipes that go into the
ground will work. But the best choice for a ground would be an 8-foot (2.4m)
copper rod stuck in the ground near the antenna. (If you want to use anything
other than the rod for a ground, contact someone knowledgeable about housing
construction and safety - you don't want to accidentally use a hot water or
gas pipe. You also need to know your local building codes.)
* Once I hook up my CB and antenna, is the radio ready to use?
--------------------------------------------------------------
No. When you get a new CB and/or new antenna, the CB and the antenna must be
tuned or "matched." To do this, you need an SWR meter which is a device that
measures the impedance between the radio and the antenna. SWR stands for
"Standing Wave Ratio." The lower your SWR, the better your match. First
timers are recommended to get help from a knowledgeable person but some notes
about the process are included here.
You do NOT want your SWR reading to be over 3:1 ratio on any channel. It can
damage your radio. A "perfect" match is 1.0:1 which gives you the best
efficiency for your radio's output. However, "perfect" isn't possible so 1.1:1
is the best you can hope for. Even 1.5:1 is acceptable, but it isn't as good.
You will only be able to achieve your best match on one or a small group of
channels. The SWR will increase on each channel as you get further from that
point. So 2:1 may even be unavoidable on the extremes, like Channels 1 and/or
40. If you know you're going to use one channel most of the time, try to
put your best match there. Otherwise, just center it at Channel 20 so you
can use all 40 channels optimally.
You may find SWR meters at places like Radio Shack or amateur radio dealers.
Further information about Standing Wave Ratio can be obtained from the ARRL
Handbook. (ARRL is the American Radio Relay League. Their annual handbook
is full of information on many different aspects of amateur radio but the
basic concepts apply in all radio bands.)
Most stores that sell CB radios will have an SWR meter and someone who knows
how to use it. But they will charge for their services.
* What are good antenna characteristics and what are some good antennas?
------------------------------------------------------------------------
Antennas have to be designed to transmit and receive on the band that you
are using. CB is located in the 11-meter band. (They call it that because
the wavelength is about 11 meters.) CB antennas range in height from a little
under 2 feet (24 inches) up to 108 inches.
The 1/4 wave whip (108") will offer better reception and transmission
capability over a shorter, coiled or "loaded" antenna.
VERY short antennas, or multiple antennas that aren't "phased" properly
will result in a very poor signal. Remember, for cophasing antennas,
they must be 1/4 wavelength apart which, for the 11 meter band, is around
9 feet. Most cars aren't wide enough to allow antennas to be placed 9 feet
apart. The other characteristic of cophasing is that it is much more direc-
tional than a single antenna. It will transmit and receive MUCH better along
the axis of the car than sideways off the car so if you want a omnidirectional
antenna, you don't want cophasing (so you only want one antenna.)
Another subject of common questions is about antennas which receive AM/FM
broadcast stations and act as a CB transceiver antenna. User experiences
on this newsgroup vary widely with each brand. (The motorized ones seem to
have the least favor among the postings we've seen.) In general, these
antennas work but are not nearly as good as a dedicated CB antenna. You have
to weigh the advantages and disadvantages for your circumstances.
Good brands of dedicated CB antennas in the USA include (but are not
necessarily limited to) Hustler, Wilson, FireStick and K-40. In France, some
common brands are President and Magnum.
Newsgroups: rec.radio.cb,rec.radio.info,rec.answers,news.answers
From: ikluft@oes.amdahl.com (Ian Kluft)
Subject: rec.radio.cb Frequently Asked Questions (Part 3 of 4)
Message-ID:
Followup-To: rec.radio.cb
X-Content-Currency: This FAQ changes regularly. When your saved or printed copy
is over 9 months old, please obtain a new one from rec.radio.cb or
news.answers on NetNews, from rtfm.mit.edu or ftp.amdahl.com via FTP, or
from listserv@rtfm.mit.edu via e-mail.
X-Disclaimer: Any opinions expressed are those of the authors and not
necessarily those of Amdahl Corporation.
Keywords: FAQ RADIO CB
Sender: netnews@uts.amdahl.com (Usenet Administration)
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X-Posting-Frequency: posted on the 7th and 22nd of each month
Reply-To: cb-faq@oes.amdahl.com (CB FAQ Coordinators)
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References:
Date: Wed, 22 Feb 1995 06:12:35 GMT
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Posted-By: auto-faq 3.1.1.4
Archive-name: radio/cb-faq/part3
Revision: 1.1 08/21/94 21:58:22
Rec.radio.cb Frequently Asked Questions (Part 3: Communication)
---------------------------------------------------------------
THIS ARTICLE IS INTENDED TO BE A FREE RESOURCE FOR THE BENEFIT OF USENET
READERS. YOU MAY COPY AND REDISTRIBUTE IT UNDER THE CONDITION THAT THIS
MESSAGE AND CREDIT TO THE EDITORS AND CONTRIBUTORS ARE INCLUDED WITHOUT
MODIFICATION. Material from the FAQ may be used to answer any questions.
Corrections and updates are welcome.
Questions discussed in Part 3: (dates indicate last modification)
* Which 10-codes are most commonly used? (7/91)
* What are the CB 10-codes? (7/91)
* Where are 10-codes used? (3/92)
* What are some of the more common Q-codes? (3/92)
* What are some tips for communicating with others on the CB? (12/91)
--Rec.radio.cb Frequently-asked Questions-----------------------------Part 3--
* Which 10-codes are most commonly used?
----------------------------------------
When getting started, remember at least the following 10-codes:
10-1 Receiving Poorly
10-4 Ok, Message Received
10-7 Out of Service, Leaving Air (you're going off the air)
10-8 In Service, subject to call (you're back on the air)
10-9 Repeat Message
10-10 Transmission Completed, Standing By (you'll be listening)
10-20 "What's your location?" or "My location is..."
Commonly asked as "What's your 20?"
and maybe also this one...
10-100 Need to go to Bathroom
Also, remember that 10-4 only means "message received". If you want to say
"yes", use "affirmative". For "no", use "negative".
* What are the CB 10-codes?
---------------------------
10-1 Receiving Poorly
10-2 Receiving Well
10-3 Stop Transmitting
10-4 Ok, Message Received
10-5 Relay Message
10-6 Busy, Stand By
10-7 Out of Service, Leaving Air
10-8 In Service, subject to call
10-9 Repeat Message
10-10 Transmission Completed, Standing By
10-11 Talking too Rapidly
10-12 Visitors Present
10-13 Advise weather/road conditions
10-16 Make Pickup at...
10-17 Urgent Business
10-18 Anything for us?
10-19 Nothing for you, return to base
10-20 My Location is ......... or What's your Location?
10-21 Call by Telephone
10-22 Report in Person too ......
10-23 Stand by
10-24 Completed last assignment
10-25 Can you Contact .......
10-26 Disregard Last Information/Cancel Last Message/Ignore
10-27 I am moving to Channel ......
10-28 Identify your station
10-29 Time is up for contact
10-30 Does not conform to FCC Rules
10-32 I will give you a radio check
10-33 Emergency Traffic at this station
10-34 Trouble at this station, help needed
10-35 Confidential Information
10-36 Correct Time is .........
10-38 Ambulance needed at .........
10-39 Your message delivered
10-41 Please tune to channel ........
10-42 Traffic Accident at ..........
10-43 Traffic tieup at .........
10-44 I have a message for you (or .........)
10-45 All units within range please report
10-50 Break Channel
10-62 Unable to copy, use phone
10-62sl unable to copy on AM, use Sideband - Lower (not an official code)
10-62su unable to copy on AM, use Sideband - Upper (not an official code)
10-65 Awaiting your next message/assignment
10-67 All units comply
10-70 Fire at .......
10-73 Speed Trap at ............
10-75 You are causing interference
10-77 Negative Contact
10-84 My telephone number is .........
10-85 My address is ...........
10-91 Talk closer to the Mike
10-92 Your transmitter is out of adjustment
10-93 Check my frequency on this channel
10-94 Please give me a long count
10-95 Transmit dead carrier for 5 sec.
10-99 Mission completed, all units secure
10-100 Need to go to Bathroom
10-200 Police needed at ..........
* Where are 10-codes used?
--------------------------
10-codes originated in the USA and are, apparently, only used in English-
speaking countries. However, no matter which codes are used in your country,
be aware that there are local dialects in every urban area and region. You
have to listen to others to learn the phrases and codes in you area.
Be aware that the use of codes specifically to obscure the meaning of a trans-
mission is probably illegal in most countries. The difference is this - codes
which are well known and make communications shorter or more efficient are
normally allowed.
* What are some of the more common Q-codes?
-------------------------------------------
Q-codes are used in many kinds of radio communications, including CB sideband
but not typically on CB AM. (If your radio doesn't have sideband, don't
worry about Q-codes.) Q-codes originated with amateur radio but their use in
CB, even more so than 10-codes, can vary depending on who published the list.
The following is an abbreviated list of Q-codes borrowed from amateur radio:
QRM man made noise, adjacent channel interference
QRN static noise
QRO increase power
QRP reduce power
QRT shut down, clear
QSL confirmation, often refers to confirmation cards exchanged by hams
QSO conversation
QSX standing by on the side
QSY move to another frequency
QTH address, location
The following is from a list of Q-codes used by the X-Ray Club (a sideband-
users club headquartered in Paradise, California):
QRL Busy, Stand By
QRM Man Made Interference
QRT Stop Transmit or Shutting Down (same as 10-7 on AM)
QRX Stop Transmit or Standing By
QRZ Who is Calling?
QS Receiving Well
QSB Receiving Poorly
QSK I have something to Say or Station breaking
QSM Repeat Message
QSO Radio Contact
QSP Relay Message
QSX Standing By (same as 10-10 on AM)
QSY Changing Frequency
QTH My Location is... or What's your location?
QTR Correct Time
Q-codes may be used to ask questions (QTH?) or to answer them (QTH is 5th &
Ivy Streets.)
The ARRL Handbook and the ARRL operating guides have more complete listings
of those used for amateur radio. (ARRL is an amateur radio organization.)
Historically, the Q signals were instituted at the 'World Administrative Radio
Conference' (WARC) in 1912. Because of their international origin, Q-codes
may be more accepted outside English-speaking countries than 10-codes are.
* What are some tips for communicating with others on the CB?
-------------------------------------------------------------
The following is a list that is generally considered proper procedure or
polite when using a CB radio. It can also be considered a beginner's survival
guide. This list was compiled from common problems that have plagued beginners
since CBs first became popular.
- When two people are talking, essentially they temporarily "own" the channel.
US FCC regulations say that they have to give other people opportunities to use
the channel if they're going to use it more than several minutes. But it is
not up to an outsider to "take" the channel from them.
- Take care not to "step on" other units (i.e. transmitting at the same time
as they are, thereby making both your transmissions unreadable.) This usually
means that you should adjust your break squelch level so that you can hear the
other unit and then only begin to transmit when you can't hear anyone else.
- NEVER deliberately key over someone else. Nobody likes that.
- If you hear one unit break for another unit, give some time for the unit
to respond before you say anything yourself. (Keep in mind that they may have
to fumble for a microphone in a moving car or dodge furniture enroute to a
base station.) Remember, the calling unit has the channel.
- If you want to talk on a channel that is in use, it is very likely that your
initial transmissions will accidentally "walk over" someone elses. So you must
keep them short. The word "break" is generally accepted. Try to time it in
a pause in the conversation.
- Even when your "break" has been recognized, keep your next transmission
short. For example, "Break one-seven for Godzilla" if you're on Channel 17 and
looking for someone whose handle is Godzilla. If Godzilla doesn't answer in
a reasonably short amount of time, it doesn't hurt to say "thanks for the break"
to the units that stopped their conversation for you.
- If you break on an open (unused) channel, you don't have to be as brief. For
example, "Break 17 for Godzilla. Are you out there Godzilla?". However, the
short form is perfectly acceptable, too. Use what fits your style.
- If someone speaking to you gets "walked over" so that you can't understand the
message, you basically have two options. You can tell the person you were
listening to, "10-9, you were stepped on", or you can find out what the breaker
wants, "Go ahead break", before returning to your original conversation. You
should eventually recognize the breaker and find out what they want.
- If two people are talking and you would like to interject a response, you
will probably just walk over someone. Use the procedure above to properly
break into the conversation.
- If someone doesn't answer your breaks after two or three attempts. Stop and
wait for several minutes or, in mobile units, for several highway miles or
city blocks. Others may have their radios on and don't want to listen to the
same break more than three times in succession.
- In other circumstances, improvise. Take into account other people's points
of view. Give people proper access to the channel and try not to do anything
to annoy other units.
- If you make a mistake in any of the procedures above, don't waste air time on
a busy channel by apologizing. (If the channel isn't busy, it's your choice.)
Just try to do it right in the future. Everyone takes a little time to learn.
OK, now you know how to conduct yourself on the radio. However, there are and
will probably always be units that don't. Be patient. You don't have auth-
ority to enforce any rules so don't break any by trying.
Newsgroups: rec.radio.cb,rec.radio.info,rec.answers,news.answers
From: ikluft@oes.amdahl.com (Ian Kluft)
Subject: rec.radio.cb Frequently Asked Questions (Part 4 of 4)
Message-ID:
Followup-To: rec.radio.cb
X-Content-Currency: This FAQ changes regularly. When your saved or printed copy
is over 9 months old, please obtain a new one from rec.radio.cb or
news.answers on NetNews, from rtfm.mit.edu or ftp.amdahl.com via FTP, or
from listserv@rtfm.mit.edu via e-mail.
X-Disclaimer: Any opinions expressed are those of the authors and not
necessarily those of Amdahl Corporation.
Keywords: FAQ RADIO CB
Sender: netnews@uts.amdahl.com (Usenet Administration)
Supersedes:
X-Posting-Frequency: posted on the 7th and 22nd of each month
Reply-To: cb-faq@oes.amdahl.com (CB FAQ Coordinators)
Organization: Amdahl Corporation - Open Enterprise Systems Division
References:
Date: Wed, 22 Feb 1995 06:12:44 GMT
Approved: news-answers-request@MIT.Edu,rec-radio-info@ve6mgs.ampr.ab.ca
Expires: Sun, 12 Mar 1995 03:10:04 GMT
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Posted-By: auto-faq 3.1.1.4
Archive-name: radio/cb-faq/part4
Revision: 1.1 08/21/94 21:58:25
Rec.radio.cb Frequently Asked Questions (Part 4: Technical Trivia)
------------------------------------------------------------------
THIS ARTICLE IS INTENDED TO BE A FREE RESOURCE FOR THE BENEFIT OF USENET
READERS. YOU MAY COPY AND REDISTRIBUTE IT UNDER THE CONDITION THAT THIS
MESSAGE AND CREDIT TO THE EDITORS AND CONTRIBUTORS ARE INCLUDED WITHOUT
MODIFICATION. Material from the FAQ may be used to answer any questions.
Corrections and updates are welcome.
Questions discussed in Part 4: (dates indicate last modification)
* What is single sideband? (11/92)
* Do I really get 120 channels on a radio with single sideband? (12/91)
* What are "linear amplifiers" and can I use them with a CB? (7/93)
* Who is "Skip" and why can I hear him all the way across the continent? (7/93)
* How can I reduce engine noise on my mobile CB? (3/92)
* What is GMRS? (9/93)
* Where can I learn more about radio? (3/92)
--Rec.radio.cb Frequently-asked Questions-----------------------------Part 4--
* What is single sideband?
--------------------------
To understand single-sideband (SSB), one must first have a picture of what's
going on in a normal AM (amplitude modulation) transmission. For example, on
Channel 21 (in North America, Australia, and Europe), a "carrier" is transmit-
ted at 27.215 MHz. Your voice (or whatever you're transmitting) is used to
change (modulate) the height (amplitude) of the signal so that it can be
reconstructed as your voice on the receiving end.
Actually, the amplitude of the carrier does not change. The addition
(modulation) of another signal, like your voice, onto the carrier will increase
the amplitude at other frequencies adjacent to the the carrier. A 300 Hz tone,
for example, would add signals 300 Hz above and below the carrier. Every
frequency component of your voice has the same additive effect. These modula-
tion effects are the upper and lower sidebands of the transmitted signal.
Normal AM transmissions include the carrier signal, the upper sideband (USB)
and lower sideband (LSB). The difference in frequency from the bottom of the
lower sideband to the top of the upper sideband is called the bandwidth of the
signal; it will be twice as wide as the highest frequency modulated onto the
carrier. (For poorly filtered radios, this can unintentionally interfere with
adjacent channels if the bandwidth is too wide. Poor filtering becomes easily
noticeable at higher power levels.)
There is enough information in either sideband to reconstruct the original
signal. Therefore, radios which can use single sideband are able to filter
out the carrier and the opposite sideband before transmitting them, leaving
either the upper sideband or lower sideband, as selected by the CB operator.
Obviously, for a conversation to take place, both the transmitting and
receiving radios have to be on the same channel and sideband setting (i.e.
Channel 25 LSB.) Some additional tuning will be necessary with a "clarifier"
control.
Assuming proper filtering within the radios, it should be possible for sep-
arate conversations to occur on the upper and lower sidebands of a given
channel without interfering with each other.
* Do I really get 120 channels on a radio with single sideband?
---------------------------------------------------------------
[This applies to the USA, Australia, Canada, and any other countries that use
AM and SSB on the same 40-channel band.]
Yes and no. SSB does give you 120 different communications paths (40 AM, 40
USB, and 40 LSB) but they are not free of interference from each other. The
upper and lower sidebands will interfere with the AM channel and vice versa.
With some radios, even the opposite sidebands can interfere with each other.
For example, (and this works for any channel - just fill in a different
number from 1 to 40) Channel 17 has an AM channel that every radio can use.
Radios with SSB will also be able to use the upper and lower sidebands.
However, within a few miles of each other, you can't effectively use the
AM channel if people are talking on either sideband. Though not as strong,
users of sideband will know if someone is using the AM channel but the higher
legal power settings on sideband give them an advantage.
* What are "linear amplifiers" and can I use them with a CB?
------------------------------------------------------------
In the USA, UK, Australia, Japan, France, Germany, Canada, New Zealand, and
Russia it is ILLEGAL to use a linear amplifier on Citizen's Band radio. In
the USA and Australia, the maximum amount of power that is rated for CB is 4
watts on AM and 12 watts PEP (peak envelope power) on sideband. In Japan,
the Citizen's Radio band is limited to 1/2 watt on AM and the Personal Radio
band is limited to 5 watts on FM. And the list goes on... we have not yet
heard of any country that allows more than 4 or 5 watts on AM/FM or 12 watts
on SSB.
For other countries, if there is a power limit on CB transmissions, any
amplifier that boosts a radio's power beyond that point is obviously in
violation.
Linear amplifiers allow a radio to transmit using much greater power than
is legal. They may range from 30 watts to above 1000 watts. The problem is
that, in reality, you can't communicate with anyone you can't hear. But you
can easily interfere with people you can't hear if you use more than legal
power. So a good antenna is the best solution for getting better range out of
your CB.
The reaction to questions about linear amplifiers on this newsgroup will vary
with the country you are from. In countries where they are illegal, you will
probably find yourself severely flamed... In other countries, to avoid a
negative response, you may want to limit the distribution of the article to
your country or continent, as appropriate.
Besides, most black-market linears are low quality and will distort your
signal and interfere with consumer electronics or other radio services.
(Stray signals from a linear outside of the CB frequencies can bring a swift
response from whoever it interferes with.) It is far better to run a clean
radio with a clean signal into a high-quality coaxial feedline and antenna
tuned for low SWR.
Most radios are deliberately undertuned from the factory (to make sure that\
they are well within type-acceptance limits). Take it down to a 2-way radio
shop and get it a "full-legal maxout" to 4 Watts AM, 12 Watts SSB at 100%
modulation.
* Who is "Skip" and why can I hear him all the way across the continent?
------------------------------------------------------------------------
If you've heard the term "skip" before, it refers to a condition where a radio
signal bounces (actually, refracts, but that's getting technical) off the Iono-
sphere, a higher layer in the Earth's atmosphere. For all practical purposes,
this only happens during daytime hours because the Sun's radiation charges up
the Ionosphere and allows the signals to be bounced back to the surface. (Some
residual "charge" remains in the upper atmosphere during the night but it is
normally not as noticeable in the 11-meter band.)
It's called "skip" because, in terms of where a given signal can be heard, it
skips over a long distance before reaching the surface again. The distances
vary but they can easily be over 1000 miles (1600km). For example, in Califor-
nia, under skip conditions it's possible to hear signals from Alabama or other
eastern states.
However, skip is often not a reliable means of communication. Besides, it may
also be illegal to intentionally use skip for communications. For example, in
the USA you may not use CB for communications beyond 150 miles. (150mi =
240km) CB is intended for local communications. However, in Russia, there is
no distance restriction so skip is legal when conditions allow you to make a
contact.
Skip signals are normally weak, though enough of them from different places
can add up to a lot of noise. If you hear a strong signal, the person is prob-
ably using a linear amplifier which, as discussed above, is illegal in at least
the USA, UK, Japan, France, and Germany and frowned-upon almost everywhere.
Though there are some conditions when a legally-powered station with a special
antenna can create a strong signal via skip, these are rare.
Most CB users' experiences with skip is to turn their squelch higher to cut
out the heavy background noise during the daytime. This is a bigger problem
with AM than with FM because FM has a "capture effect" where the stronger
signal wins. Anyone you talk to (locally) will have to be close by to send a
strong enough signal to overcome the background noise and your squelch setting.
If you use AM, there's really no way around this so get used to it.
* How can I reduce engine noise on my mobile CB?
------------------------------------------------
If you have problems with engine noise in a mobile installation, there are
several things you can do to reduce or eliminate the problem.
- Make sure you've completely installed your CB and the antenna is grounded
properly. Check the amount of noise with and without the antenna connected.
If the noise is greater when the antenna is connected, the source is probably
the ignition system. If the noise remains unchanged after disconnecting the
antenna, the source is probably in the CB's power supply.
- For ignition noise, there are several parts of the vehicle that can act like
RF noise transmitters if not properly grounded. Check (and connect to
ground on the chassis/frame, if necessary) the engine block, hood, muffler,
and exhaust pipe.
- Ignition noise can be further reduced by installing "magnetic suppression"
spark plug cables. (These are significantly more expensive than normal
spark plug cables.)
- For power supply noise, check if you have a capacitor attached to your
ignition coil, alternator, and distributor. These can act as filters right
at the source of the noise.
- Ensure that your antenna feedline and power lines are as far as possible from
any of the noise sources mentioned above, especially the engine block.
- A shielded power cable can help as well. Make sure it is of sufficient
guage to handle your radio's power consumption and that the shielding has a
good, strong connection to ground on the vehicle chassis or frame.
- Electronics stores such as Radio Shack sell cheap power filters for noise-
reduction purposes. You get what you pay for, though - most comments on this
newsgroup are that they are not as effective as the other measures above.
Of course, the best performance can be obtained from a more expensive radio
with better noise suppression circuits. These measures, however, will improve
the engine noise levels for nearly any mobile radio.
* What is GMRS?
---------------
[This applies only to the USA.]
The General Mobile Radio Service is another personal radio band. Its frequency
allocation is in the ultra-high frequency (UHF) spectrum, co-located with some
other radio services in the range from 460-470 MHz. It requires a license but
there is no examination. Though GMRS is not CB, it is listed here because it
is intended for use by individuals. A single GMRS license also covers the
members of the licensee's household. The license fee is US$35 for 5 years.
frequencies (MHz) modulation description
460 - 470 FM General Mobile Radio Service (GMRS)
regular channels (simplex or repeater
outputs, repeater inputs are 5MHz higher)
462.550 462.575 462.600 462.625
462.650 462.675 462.700 462.725
simplex low-power channels
462.5625 462.5875 462.6125 462.6375
462.6625 462.6875 462.7125
31.0-31.3 GHz any mode microwave band now open for individuals
to use, requires GMRS license
GMRS is used for mobile-to-mobile or base-to-mobile communications but
base-to-base communications are prohibited. One useful aspect of GMRS is that
repeaters are allowed so that a mobile GMRS station can extend its range well
beyond the limits of an ordinary 5-watt mobile transmitter.
Only individuals may obtain GMRS licenses. Some businesses still have licenses
from before the rules were changed in 1989 but no new licenses are being issued
to "non-individuals."
Recent changes in regulations have given GMRS licensees access to the micro-
wave band at 31.0-31.3 GHz for both fixed and mobile use. The licensee must
notify the FCC of each transmitter with a standard FCC form.
For more information, you can obtain compressed text files via anonymous FTP
at ftp.amdahl.com in the /pub/radio/other directory in the files called
gmrs.intro.Z and gmrs.microwave.Z. If you don't have access to the Internet
or need help with FTP, see the rec.radio.amateur.misc FAQ, Part 3.
Another source of information is the Personal Radio Steering Group. A reader
said they have lots of good information and are enthusiastic about GMRS.
Personal Radio Steering Group
PO Box 2851
Ann Arbor MI 48016
Phone: (313) MOBILE 3
BBS: (313) 995-2100
Compuserve: 73016.163
* Where can I learn more about radio?
-------------------------------------
If you like what you see here and want to learn more about the technical
aspects of radio, you may be interested in getting an amateur ("ham") radio
license. These licenses are available in almost every country in the world,
including all of the countries that have CB.
Amateur radio is very different from CB. This is neither good nor bad - they
have different purposes. With the training that a licensed amateur radio
operator is expected to have, much more powerful transmitters are allowed -
but the operator should know when that power is not necessary and refrain from
it. Amateurs have no limits on the range of their communications (at least,
by law or treaty) so it is possible to make distant "DX" contacts using atmos-
pheric skip, satellites, or even bouncing signals off the Moon. Again,
training and the willingness to cooperate (to avoid interference with others)
are necessary for obtaining and using these privileges.
Japan, Sweden the USA and many other countries have authorized a new amateur
radio "no-code" license which requires only a written test (no morse code).
However, the test is challenging enough to necessitate several weeks of study
(or a few days if you already have some familiarity with the subject) so
don't go unprepared. More information, see the FAQ articles in the
rec.radio.amateur.misc newsgroup.
Even if you don't want the license, books intended for amateur radio operators
make available a wealth of information on understanding transmitters, recei-
vers, antennas, modulation, signal propagation, electronics, and many other
topics which also apply to CB.