I am trying to research CB radios i know they are now using FM in trying to compare them to each other its a little confusing to me. I want one that will pick up both AM and FM and a few of them list that as a feature. I understand both units need to be FM capable to talk to each other but some don’t list any type of frequency use and some just say UHF. Is the UHF the same as AM?
If it is UHF, it isn’t CB - CB is down in the 27MHz frequency band, so very different from UHF that is usually 400MHz or much higher.
Radios have a frequency and a mode, how the audio or data is carried on the basic carrier wave. 27MHz would be the frequency, and amplitude modulation was the original mode. Now we can have frequency modulation too/instead. There are pros and cons for both systems.AM used to be thought of as duller sounding and interference prone, but often easier to pick out words at a distance. FM offered better audio quality, but when range increases it starts to get very hiss, very quickly. General concensus is FM is better for non-experts, but many disagree. 27MHz CB is technically High Frequency (HD). UHF - as in Ultra-High Frequency is not CB, it’s the US GMRS/FRS system, or UK PMR446. Both let you chat to people.
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I figured it was something like that they put different radios up for comparison but its not always apples to apples. i will make sure that it says AM/FM CB radio in the actual description. Thank you.
AM stands for Amplitude Modulation and FM is for Frequency Modulation. They are separate ways of altering a signal for transmission, with AM changing the size of the wave and FM changing the distance between the waves.
On the other hand, UHF (Ultra High Frequency) and VHF (Very High Frequency) are ways of categorizing the distance between the waves of a signal. UHF sports less distance than VHF. Since UHF and AM measure different aspects of a signal, it can be both at the same time. UHF can be either AM or FM, and the same goes for VHF.
To answer the first part of your post, plenty of CB radios these days support both AM and FM, such as our recent President models that have released.
These include:
President Thomas FCC AM/FM Mobile CB Radio
President George FCC AM/FM/SSB Mobile CB Radio
President Harrison FCC AM/FM Mobile CB Radio
President Ted FCC AM/FM Mobile CB Radio
President Randy II FCC AM/FM Handheld CB Radio
President Jerry FCC AM/FM Handheld CB Radio
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Thank you for the info
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For clarification, my wording in the last message was slightly off. To avoid any misunderstandings, UHF and VHF are frequency types based on how many cycles per second a signal has, and they do not pertain to the distance of a wave at all. AM specifically changes the amplitude of a signal while FM changes the frequency. This means that UHF and AM are not mutually exclusive. I apologize if this caused any confusing or contradictory information!
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Thanks. I understand the difference between AM/FM but i always think of the AM band of frequencies. Having it applied to other bands makes sense but my brain is a bit slow to grasp because i associate AM with that band lol. I hope that makes sense. I just wanted to make sure i could contact as many users as possible by having the two modes i know that if you have a new FM cb you can only talk with people who also have FM cb’s. I dont know how common they are yet. If most people still have the AM version having just FM would be kind of pointless.
The other thing is the SSB functions but i think that is another layer i will need to learn about but i think that will be a bit down the road for me.
Leave the USA, and CB is NOT on 27 Mhz. Doy!
Well, apart from Canada, UK, Europe, Australia, Malaysia, Indonesia, lots of places in South America and even into eastern europe like Bulgaria. Most of these countries also added either VHF or UHF systems for citizen to citizen commmunications, like GMRS, FRS, PMR446 and similar. Few of the VHF and above systems were called CB radio though?
CB radio has been the same 40 channels since 1977 and 23 channels longer than that.
Only true in the USA.
Sort of. CB is an American concept. In other countries who invented their own spec they may well have adjusted channels or modes for their own use, but they’re not CB, they’re ’CB’. This topic actually says UHF CB which has never existed. Your FRS, GPRS, our PMR446 have never been CB, just radio systems for citizens. CB is well, CB!
Thank you everyone, i recently read an article that explained the SSB and i understand how it relates to the CB frequencies. Again tank you all for the input.
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