Tuesday, November 9, 2010

Ham and CB Radio Communication - A Basic Primer to Two-Way Radio

     Radio communications have come a long way from the original concept derived from Marconi's discovery of electro-magnetic radiation (radio waves).  Marconi conceived that an electro-magnetic pulse, sent through the air, would create an electron flow when it passes through a ferrous metal source.  Such an electron flow can then be amplified to create sound if the pulses are emitted a certain way.  This is the simplest representation of what Marconi discovered, and by its revelation many things become clear.  Many possibilities have derived from such thought, and clearly all of mans inventions come from such seemingly small realizations.

     At its base, radio communication is fairly simple.  During our modern age, there are many forms, so many in fact that their discussion will be outside the scope of this article.  Basically, we have two forms of Radio Communication in the hobby realm.  Citizen's Band and Short Wave are the two that most of us are somewhat familiar with.  Though short wave offers many optional communication modes, we are going to look at 'full duplex' and 'half duplex' modes involving AM and FM communications.
Modes of Communication

        1).  In full duplex mode a radio is capable of transmitting and receiving date or voice over two channels at the same time.  This is important for transmitting visual and voice date as in television.  Ham radios are capable of such transmission, but we will not delve that far into it here.  Microwave communication is another form of full duplex transmission.  Cell phones have this capability and ham radio operators can definitely tune into your telephone conversations.

        2).  In half duplex we have the ability to transmit and receive on one channel, but not at the same time.  The radios    we normally use, CB's or Walkie Talkie, operate in half duplex mode.  As a consequence, we must make our own breaks during transmission so the people we are talking to can respond.  Because of this, a protocol has been developed to assure proper etiquette during conversation.  Words such as, 'Roger' and 'Ten Four' are used to indicate a transmission was received, or ask for confirmation it was received.  In addition there are 10-Codes and Q-Codes that have developed in the United States.  The ones listed below should be memorized as the most commonly used.

Most Common 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?

Most Common Q-Codes:

          * 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

     For a beginner, the codes listed above are standard.  Either the 10 Code or Q Code can be used interchangeably on the Citizens Band or Ham Radio arena.  Ham operators have to be licensed in this country.  This assures that an operator knows the rules of the road, and will not be unknowingly interfering with other communication bandwidth areas.  It is possible to transmit into television frequencies and bandwidth, as well as interfere with cell telephone conversations and transmissions.  In fact, short wave ham radio operators have the whole spectrum of frequencies available to them and inappropriate use can cause serious civil problems.

     Fire and Police bands can be disrupted during emergencies; pilots can be misled and so on.  This is way it is tightly regulated.  However, it is much easier to get a license now, than in the past.  You do not have to be an electronic technician anymore.  Simply learning the rules of the road and proper use of the equipment can get you a basic ham radio license.  As a beginner, you should buy a receiver and antenna system first.  Enjoy listening to the different ham and citizen band conversations, as well as marine and private pilots.  You'll be able to listen to people from all around the world.  I am sure it will amaze you and pick your interest to no end.

     A good ham receiver can be bought for as little as $450.00, with and antenna and mast, wiring included at around $250.00.  You might even consider buying second hand equipment for an even better deal, as many radio enthusiast upgrade looking for a way to save on their new purchase.  Citizen band radios can be had for as low as $95.00, with 40 channels available.  An antenna system for a CB home base would run about $180.00, while again you could find something cheaper second hand.  These are ballpark figures, but accurate enough.  Citizen band radios do not require a license to operate.  The units are transceivers, meaning they are capable of half-duplex mode transmitting and receiving.  Power on these units is usually limited to 5-10 Watts.  Your average ham has capabilities depending on license, to transmit at 1.5 KW (1500 watts), and are very powerful.

     Whatever you decide, I hope you try the hobby of radio communication.  It can be a great hobby you can share with family and friends.  The real value is in the sharing and learning that you and your children will enjoy.  It can spark interest in the electronics field, leading both you and the kids wanting to know more about the science and physics related to radios and how they work.  All of this would be valuable and enduring, guaranteeing many memories that will last forever.

     Good luck should you become involved.  Have lots of fun and enjoy!

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