Frequently Asked Questions

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Frequently Asked Questions

Post  Cobra on Sat Jan 26, 2008 9:03 am


How far will my mobile CB radio transmit?
With a proper single antenna setup, a good rule of thumb is 1 mile per watt of output power. Most newer radios are a the maximum allowed 4 watts which gives you about 4 miles.

How far will my hand held CB radio transmit?
This depends on where you are at with the radio, and what antenna you are using for it. If you are outside, you will get about 2 to 3 miles. If you attempt to use a hand held in a vehicle, home, or other enclosure without an external antenna you will have a very poor signal. You can fix this problem by using an external antenna. A good example of this is a magnet mount antenna mounted on a vehicle that runs a wire back inside the vehicle which can be plugged into the hand held CB radio.

How are CB radios powered?
Mobile radios generally get their power from the vehicles 12 volt system. They are wired in just like a car stereo. Just remember, red is hot, black is ground. Handheld radios typically run on batteries and/or ac power supplies. Base station radios usually just plug into the wall.

How to I make my CB work with a PA horn?
If your CB is PA capable (most newer radios are) then you just need to find the PA jack, plug in your PA horn, and flip the PA/CB switch on the radio. When you key the mic and talk, you will be broadcast over the PA horn instead of the airwaves.

What are weather channels?
Any CB radio that has NOAA weather channels can receive (not broadcast on) a special set of channels that are constantly reporting local weather conditions and emergency weather. Some radios are even programmed to alert you of dangerous weather even when they are switched off.

What's special about channels 9 and 19?
Channel 9 is the universal (or at least American) CB emergency channel. In most areas it is monitored by local law enforcement at all times. Channels 17 & 19 are commonly used channels by truck drivers. 19 is often used by drivers going east or west, 17 by drivers going north or south.

What are all these dials!?
The loads of features on modern CB radios can be confusing. Here are some explanations for a few of them:

  • Squelch/SoundTracker™/ANL/Noise Blanker/ESP™ - All these type of features reduce "noise" in your broadcast and/or reception. Some are dials and some are switches. The dials reduce the amount of background noise, engine noise, electrical noise, etc as they are turned up. The switches reduce certain amounts of noise when switched on, and do nothing when off. Better radios will give you less of a problem with noise.
  • Dynamike™ Boost/Mic Gain - This feature raises the volume of your broadcast. It more or less makes it sound like you are talking louder than you actually are.
  • RF gain - This is another feature that helps control noise. It essentially turns down the signal reception. One way to think of it is standing in the middle of a forest. Each tree is a CB'er or bit of noise you are hearing. As you turn down the RF, the trees get shorter, so eventually you only see the tall trees close to you. As you turn down the RF, you only hear the strong signals close to you.
  • CB/WX switches - CB Radios with these switches are capable of receiving NOAA weather channels. You can broadcast and receive regular CB transmissions when the switch is on CB, and receive (not broadcast) the weather channels when the switch is on CB.
    PA switches - CB Radios with these switches are capable of broadcasting over a PA. You can broadcast and receive regular CB transmissions when the switch is on CB, and broadcast over PA when the switch is on PA.
  • Instant Channel 9/19 - This switch will put the CB automatically to channel 9 or 19 (whichever is selected). This is a common culprit when you can't get your CB to change channels.
  • Volume - This only turns up the volume of the speaker (the speaker putting out sound on the radio, not the person talking)


Number of posts : 16
Location : Yuma, AZ
FRN# : 0015687585
Radio Model : Cobra WX75
Registration date : 2007-10-17

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How far will my mobile CB radio transmit?

Post  brujo de la colonia on Fri Mar 07, 2008 4:43 am

Under favorable conditions (high sunspot count, good ionization of the F layers of the Earth's ionosphere) is is possible to work "skip" in the CB bands.

F layer info:

  1. The highest region of the ionosphere, extending at night from
    about 190 to 400 kilometers (120 to 250 miles) and during the day from
    about 145 to 400 kilometers (90 to 250 miles) above the earth. Also
    called F region.
  2. Either of two layers, designated F1 and F2,
    into which this region is divided during the day, extending
    respectively from about 145 to 240 kilometers (90 to 150 miles) and
    from about 190 to 400 kilometers (120 to 250 miles) above the earth.

The 11-meter band (CB Band) behaves the same as the 10-meter amateur radio band. Generally, when ever conditions are favorable towards long range communications in the 10-meter amateur radio band, they are also favorable for "skip" in the 11-meter band.

When conditions are favorable, the 10-meter band can enjoy intercontinental communications with only 25 watts (or even less) of output power. Under the same conditions, the CB band can experience ranges such as Yuma to Canada, or Yuma to Florida, but seldom ever intercontinental range due to CB band's 5-watt input power limit, as well as the fact that most CB receivers are not nearly as "hot" as more expensive and better engineered amateur radio receivers, as well as most CB operators do not use optimal antenna configurations (like 102" whip, phased arrays, or yagi beam antennas).

On the other hand, if conditions are not favorable, even the rich 10-meter band amateur radio operator running 1,000 watts and a high gain directional antenna on a 60' tower will be challenged to get any more distance out of his station than a CB operator using a 4' antenna out of a car.

However, FCC regulations disallow "DX" long-distance communications, or "skip" (over 150 miles in this case) with CB. However, directional antennas may be used to enhance communications within the legal range.

Because regulations in nearly all countries that have CB radio service specify that the service is intended for short-range communications (UK regulations prohibit distances in exces of 80 miles), CB radio manufacturers can get away with having lesser engineering quality than amateur radio rigs in their receiver sections. The upshot of these "less hot" CB receivers is that costs are kept down for the consumer, and that's why we can buy a new CB tranceiver for $49, rather than paying several hundred, or even thousands of dollars that amateur tranceivers typically cost.

But in the case of two people with base stations who want to talk to each other reliably over a distance of 150 miles or less, it is perfectly legal for them each to employ high gain yagi antennas, or log-periodic dipole arrays, or cubical quad antennas, on towers with rotators, and point their high gain directional antennas to each other's location, and fully exploit the maximum legal range of the CB service allowed by the FCC.

Whether in a mobile station, or a base station, if the "skip' is good, and you hear someone from an amazingly long distance away, you should not try to initiate a conversation with them, because if "the man" is listening, you could be fined and have your equipment confiscated.

brujo de la colonia

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Registration date : 2007-11-15

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