CB Radio Antennas - Huge antennas necessary?!

[Firstwave]

Just researched a few GMRS...sooo what's the difference in the two types?

Why one over the other?

Citizens band radios are limited to 4 watts. FRS Family radio service are the bubble pack walkie talkies are maxed out at 5 watts. GMRS General mobile radio service will transmit at up to 50 watts to give you the most range but do require a license at $70 for ten years. FRS and GMRS will both give you better range and clarity than CB. The only advantage of CB is if your traveling with a group that all use CB.

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[Poseidon]

Growing up as a kid we all had CB radios in our cars. Owning a couple of Jeeps through my life I enjoyed overlanding with them. I’m an avid fisherman through my life and always a surf fisherman. My Jeep were set up to be my living quarters on all my expeditions. So CBs were pretty much a staple as far as communication when off roading, also could come in as handy emergency resource if needed when overlanding. Also helped greatly with communication with other fisherman on beach finding out how’s the bite overthere. So now with my newest Jeep. I’ve been upgrading and getting it rigged out and overland ready and part of that includes my CB radio. Cobra hand held and the other being a good antenna. I’ve owned a 4 foot fire stick that I mounted in the back with the hi lift, shovel, tire and basically the hardtop and finally the fire stick peeks out about a foot. Felt it was crowded there wasn’t doing what I thought it should be, so basically upgraded to 5 foot fire stick and to tell you antenna wise it is really a much thicker and heavier antenna than the 4 foot fire stick. I was a little wowed when I first saw and felt it the new 5 foot fire stick. I also moved the mounting from back to front bumper. Right corner. No obstruction just a 5 foot CB antenna straight up into the sky. If I encounter some thick forest the antenna is easily taken off. The reception is better for sure and I’m satisfied.

 

[Titan2727]

Doesn't matter if it is a "walkie" or not... What matters is the band it is designed for. There are "walkies" that are CB band and there are ones that are for the GMRS band. You might find a *receiver* that will work on both bands, just like you have AM and FM receivers in cars even though the frequencies are vastly different, but you will not find a transmitter that works on both bands. If nothing else, you need different lengths of antenna for the different bands.

When American Adventurist said "2M", he's talking about 2 meter band. CB is pretty close to 10 meter band. Actual 10 meter band is a HAM band, but their equipment can go down into the CB frequencies also.

When I was dealing with CBs many decades ago, we were required to have a FCC license. I remember when they changed it so that you didn't need a license somewhere in the late 1970s, IIRC and we were say, "oh well, there goes the neighborhood"...

Now I'm really confused..my walkies do have GMRS?? Thought need license for that?

 

[NavyVet1959]

Now I'm really confused..my walkies do have GMRS?? Thought need license for that?

Your term "walkie" is just a shortened form of "walkie talkie" and it means a handheld transceiver. It could be any frequency band or power level. In my youth, it referred to small units that were on the 27 Mhz (CB) band, but it was also used to refer to the portable military transceivers.

https://en.wikipedia.org/wiki/Walkie-talkie

You can buy handheld transceivers in various frequency bands and they are not compatible between those frequency bands. If you have one that works on the CB band (27 MHz), you cannot expect someone on the GMRS band to be able to hear you.

More CB info:
https://en.wikipedia.org/wiki/Citizens_band_radio

There is also nothing in the term "CB" that means a fixed set of frequencies. Each country designates which frequencies can be used for "CB" and as such, it would be possible to on the same "channel number" in two countries, but the frequencies are different and the two radios would not be able to communicate with each other.

 

[Titan2727]

Your term "walkie" is just a shortened form of "walkie talkie" and it means a handheld transceiver. It could be any frequency band or power level. In my youth, it referred to small units that were on the 27 Mhz (CB) band, but it was also used to refer to the portable military transceivers.

https://en.wikipedia.org/wiki/Walkie-talkie

You can buy handheld transceivers in various frequency bands and they are not compatible between those frequency bands. If you have one that works on the CB band (27 MHz), you cannot expect someone on the GMRS band to be able to hear you.

More CB info:
https://en.wikipedia.org/wiki/Citizens_band_radio

There is also nothing in the term "CB" that means a fixed set of frequencies. Each country designates which frequencies can be used for "CB" and as such, it would be possible to on the same "channel number" in two countries, but the frequencies are different and the two radios would not be able to communicate with each other.

Yes I understand that as you made it very clear thank you

Question is can I communicate with other people either using a CB radio or walkie "talkie's" as long as we are all on the same channel through my walkie talkie? This make sense?

 

[Titan2727]

Yes I understand that as you made it very clear thank you

Question is can I communicate with other people either using a CB radio or walkie "talkie's" as long as we are all on the same channel through my walkie talkie? This make sense?

Let me better ask the question

If I'm on my "walkie talkie" on channel 10 and my buddy is on his "CB Radio" on channel 10...can we communicate?

 

[Matthew/E36]

It sounds like you want comms for emergency use...who will you be communicating with? You have someone on the other end that can help you?

If you are talking just SOL last ditch help, you can use this site to find listed repeaters in your area to see if there are any HAM repeaters which would indicate there may be some activity, or range for you to receive comms from the other end...I don't know how active CB frequencies are, but maybe someone else could confirm how likely it is you could find someone in range that can hit you. If you build up your send signal, that doesn't mean anyone can hit you back.

https://www.radioreference.com/apps/db/?stid=25

 

[Matthew/E36]

Let me better ask the question

If I'm on my "walkie talkie" on channel 10 and my buddy is on his "CB Radio" on channel 10...can we communicate?

No.

EDIT: if you and a buddy will be communicating I would recommend you both get a HAM license so you can get HAM radios to talk. If you don't like the huge antenna, just take it off until you need it. I'd assume you could find a mount that may fit a shorter (less effective) antenna, and 1/4 wave or 1/2 wave style (depending on your frequency.)

HAM gives you access to more power and frequencies than CB...

 

[NavyVet1959]

Let me better ask the question

If I'm on my "walkie talkie" on channel 10 and my buddy is on his "CB Radio" on channel 10...can we communicate?

If that "channel 10" is the CB frequency, then the answer would be yes. There is a GMRS channel 10 also, but they are most definitely not the same frequency as CB channel 10.

Just like with TVs -- your channel 10 in the US is not necessarily the same as channel 10 in some other country, so a foreign TV will not necessarily pick up any channels when in the US.

https://www.buytwowayradios.com/blog/2006/07/frs_and_gmrs_frequencies.html

The channel numbers is just a convenient way for people to refer to the actual frequency. It's the frequency and modulation method that is important. For example, we normally consider 107.5 MHz to be the FM band in the US. FM stands for "frequency modulation". There is nothing inherently prohibiting someone (at least from an engineering standpoint) of developing a radio that uses "amplitude modulation" on that frequency, but they would not be able receive each other.

https://en.wikipedia.org/wiki/Frequency_modulation
https://en.wikipedia.org/wiki/Amplitude_modulation

The US CB band uses amplitude modulation whereas GMRS and FRS use frequency modulation.

 

[NavyVet1959]

Now, in case you were wondering how those antenna lengths are determined...

It's related to the speed of the radio signal which is at the speed of light (i.e. 299,792,458 meters/sec).

An antenna tends to be most effective if it is a full wavelength. The wavelength is determined by dividing the speed of light by the frequency.

So, let's say we wanted to find the wavelength of a CB radio (27 MHz)...

299,792,458 / 27,000,000 = 11.103424370370371 meters * 39.37" per meter = 437.1418174614815".

The long whip antennas that we used to use on vehicles were 1/4 wavelength, so divide the above by 4 and you will get 109.28545436537037"

So, why did we say 102" earlier? Well, 27 MHz is just a round number and actually there is a range of frequencies, so you get choose an antenna that is in the midrange of the frequency band. Also, those type antennas had a metal coil / spring at the bottom that added about 6" or so to the overall length, thus the "109" becomes "103" or less.

For the GMRS frequencies, a full wavelength would only be around 25.5", so you can get away with a lot shorter antenna.

If you are wanting to be able to talk to one particular person, then you both need to agree on the frequency band (CB, GMRS, or whatever) you will be using and the channel (actual frequency) within that band. If you are just wanting to communicate with *anyone* that might be monitoring a channel, then you need to look at whether you are broadcasting on a frequency band that is used by many people in that area. If no one is listening, it doesn't do you much good to be able to talk a long distance.

Now, if you are in a *really* life threatening situation (i.e. one where you would even consider *paying* for a helicopter search and rescue), there are other options that might be considered. For example, PLB and EPIRB are possible considerations. They rely on satellite communication for the signal, so a clear view of the sky is important. They are for when your life is in danger. These do not necessarily allow 2-way communication, but rather just send out an emergency signal that the search and rescue people can use to find you.

 

[Titan2727]

Now, in case you were wondering how those antenna lengths are determined...

It's related to the speed of the radio signal which is at the speed of light (i.e. 299,792,458 meters/sec).

An antenna tends to be most effective if it is a full wavelength. The wavelength is determined by dividing the speed of light by the frequency.

So, let's say we wanted to find the wavelength of a CB radio (27 MHz)...

299,792,458 / 27,000,000 = 11.103424370370371 meters * 39.37" per meter = 437.1418174614815".

The long whip antennas that we used to use on vehicles were 1/4 wavelength, so divide the above by 4 and you will get 109.28545436537037"

So, why did we say 102" earlier? Well, 27 MHz is just a round number and actually there is a range of frequencies, so you get choose an antenna that is in the midrange of the frequency band. Also, those type antennas had a metal coil / spring at the bottom that added about 6" or so to the overall length, thus the "109" becomes "103" or less.

For the GMRS frequencies, a full wavelength would only be around 25.5", so you can get away with a lot shorter antenna.

If you are wanting to be able to talk to one particular person, then you both need to agree on the frequency band (CB, GMRS, or whatever) you will be using and the channel (actual frequency) within that band. If you are just wanting to communicate with *anyone* that might be monitoring a channel, then you need to look at whether you are broadcasting on a frequency band that is used by many people in that area. If no one is listening, it doesn't do you much good to be able to talk a long distance.

Now, if you are in a *really* life threatening situation (i.e. one where you would even consider *paying* for a helicopter search and rescue), there are other options that might be considered. For example, PLB and EPIRB are possible considerations. They rely on satellite communication for the signal, so a clear view of the sky is important. They are for when your life is in danger. These do not necessarily allow 2-way communication, but rather just send out an emergency signal that the search and rescue people can use to find you.

How do you tune a CB antenna?

Is it easy to do?

 

[N3PZZ]

Really want to install a CB radio - but haven't because I hate the fact of having to have a huge antenna mounted. Is that the only option or is there another option other than 4' antennas?

Use a magnet mount 5/8 wave antenna. Easy to use and remove. It can scratch painted metal surfaces. Just don't put anything between the magnet and car suface. It will cause high SWR.
If you talk alot, that will shorten the life of the finals. Something to think about.

 

[NavyVet1959]

How do you tune a CB antenna?

Is it easy to do?

You want to minimize the signal wave ratio, so you'll need an SWR meter. With the metal whip antennas, it consisted of trimming a small amount of the length of the antenna. With the shorter antennas that they are using these days, there will probably be an adjustable section that can be moved up or down after loosening a set screw. The SWR meter that I had around 40-45 years ago was bought from Radio Shack. Back then, Radio Shack was more for electronic hobbyists instead of consumer electronics.

There are probably quite a few videos on YouTube telling how to use the SWR meters. Here's one...


Considering the wattage that he's talking about, he must be using one of the licensed bands, not the unlicensed CB band.

 

[Niteshooter]

Navyvet pretty much covered it. The reason for the long antenna is wavelength if we are talking about a 102" whip. But technically it's a 1/4 wave, while you can get 'loaded' antennas which can be 1/2 to 5/8 wave or other which my memory escapes me at the moment. Seemed to me at one time there was a full wave loaded (coil mobile antenna) at one time years ago.

But besides the length placement is equally important. On a Jeep however that can get rather tricky because not only length but ground plane comes into play so mounting an antenna on your hardtop roof which is not a great option since it is not metal and therefore doesn't provide a good ground plane.

I have a loaded 5/8 wave whip mounted to the tire carrier on my CJ but again one thing to consider with placement is that it can affect the radiating angle or in other words the coverage of the antenna. Why dead centre in the middle of a metal roof is typically considered the best spot. Granted you probably wouldn't want to mount a 102" whip up there but I have seen that done back in the heyday of CB.

If range is the biggest requirement for safety reasons I might suggest getting your amateur radio operators license as that will open up a world of possibilities in terms of range and also the potential to be able to make contact with another station. Radios operate on a broader range of frequencies and at higher legal output power.

GMRS/FRS tend to be hand held units though I have seen a few in car units, but they had fixed antennas with low power output. Basically considered line of sight usage though many manufactures claim some pretty absurd ranges but read the fine print and it becomes clear that that range is highly unlikely to achieve unless conditions are idea. If just short range use within a group is the requirement then these radio might be a good choice. But in terms of calling outside of your 'group' they might not be a good choice if you consider them for safety though many local businesses use these types of radio because they are cheap and don't require a license. But would buddy in the local Home Depot respond to a mayday? Another useful feature is that many have built in VHF weather channel receivers.

CB is kind of dead though up here truckers still tend to hang out on CB channel 19 and not 10 which is pretty much just noise along with 11 which was a call channel and 9 which was monitored by some police departments and citizen groups such as REACT way back in the day. Up here french speaking truckers from Quebec tend to use CB channel 13 and if you had a CB radio with sideband (SSB) you might have hung out on lower 16. I have SSB radios in my vehicles though I typically only use 19 when doing long highway runs.

Anyhow in terms of looking 'cool/weird' my money is on dual co-phased 102" whips on the back bumper.....

 

[Titan2727]

Navyvet pretty much covered it. The reason for the long antenna is wavelength if we are talking about a 102" whip. But technically it's a 1/4 wave, while you can get 'loaded' antennas which can be 1/2 to 5/8 wave or other which my memory escapes me at the moment. Seemed to me at one time there was a full wave loaded (coil mobile antenna) at one time years ago.

But besides the length placement is equally important. On a Jeep however that can get rather tricky because not only length but ground plane comes into play so mounting an antenna on your hardtop roof which is not a great option since it is not metal and therefore doesn't provide a good ground plane.

I have a loaded 5/8 wave whip mounted to the tire carrier on my CJ but again one thing to consider with placement is that it can affect the radiating angle or in other words the coverage of the antenna. Why dead centre in the middle of a metal roof is typically considered the best spot. Granted you probably wouldn't want to mount a 102" whip up there but I have seen that done back in the heyday of CB.

If range is the biggest requirement for safety reasons I might suggest getting your amateur radio operators license as that will open up a world of possibilities in terms of range and also the potential to be able to make contact with another station. Radios operate on a broader range of frequencies and at higher legal output power.

GMRS/FRS tend to be hand held units though I have seen a few in car units, but they had fixed antennas with low power output. Basically considered line of sight usage though many manufactures claim some pretty absurd ranges but read the fine print and it becomes clear that that range is highly unlikely to achieve unless conditions are idea. If just short range use within a group is the requirement then these radio might be a good choice. But in terms of calling outside of your 'group' they might not be a good choice if you consider them for safety though many local businesses use these types of radio because they are cheap and don't require a license. But would buddy in the local Home Depot respond to a mayday? Another useful feature is that many have built in VHF weather channel receivers.

CB is kind of dead though up here truckers still tend to hang out on CB channel 19 and not 10 which is pretty much just noise along with 11 which was a call channel and 9 which was monitored by some police departments and citizen groups such as REACT way back in the day. Up here french speaking truckers from Quebec tend to use CB channel 13 and if you had a CB radio with sideband (SSB) you might have hung out on lower 16. I have SSB radios in my vehicles though I typically only use 19 when doing long highway runs.

Anyhow in terms of looking 'cool/weird' my money is on dual co-phased 102" whips on the back bumper.....

Thanks for the info!!

After thinking about it for a little, gonna pass on the CB for now

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