CB RADIO AUDIO PERFORMANCE TIPS

 
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CB RADIO MICROPHONE AUDIO PERFORMANCE
DIY TIPS - The Key to "Broadcast Quality Audio" on CB Radio
Sound Like a Million Dollars for Ten Dollars
hifi ssb cb radio audio
First let's start off by Exposing a few CB Radio myths

  • Get your cb radio "Peaked Out" and you will sound "louder" or "better"
  • Put an "echo mic" or "echo board" on your cb and you will be "louder"
  • You will talk further if you get your cb radio "Modded or "Tweaked Out"

If the things above are not true, what is "The Real Deal"? First off let me say I have been around cb radios for years but do not claim to be a "technician". You don't need a proclaimed "technician" to figure this one out. Secondly let me say the most important factors in your radio are it's design, construction and alignment. A good radio with 1 watt will outperform a 5 watt radio with poor design, construction and alignment. It's all about stability. Have you ever noticed when you hear someone with a "peaked out" cb radio whistle in to their mic you hear strange distortions in their signal. It's almost like you hear other whistles of different audio frequencies at the same time. Those are harmonics. Have you ever noticed when people get their cb radios "modded out" they sound pinched off like they have a clothes pin on their nose. They seem louder but the deep part of their voice is now gone. That is a loss of audio bandwidth. A sacrifice that appears louder, but it's not. You see the human ear is more sensitive to a higher pitch in the vocals. You will usually hear a person scream farther than a cow mooing at the same faint volume levels.

Cb Audio Bandwidth Example: Think of the transmit audio of your cb like you would tune a car stereo equalizer. You have Bass, Mids and highs. What happens when you take the bass completely out? It seems a bit louder but less dynamic. Now what would happen if you compressed all the audio into the center slider on the EQ. All EQ level sliders down but the 1 or 2Khz. How would that sound. Screechy loud, tinny and nearly distorted. This is what some people are getting when they get their radio improperly "peaked out". It's narrowing the frequency response of your transmit audio. It is of no benefit to the performance of your cb radio operations. All you are doing is tickling the higher frequencies of people's ears. "well it's so loud it's on the verge of squealing, it must be loud". No. What does that same signal sound like when they are 40 miles away at S1 signal on the meter? It sounds like someone strangling a chicken. You need all the dynamic range of the radio's audio you can get so people can understand you in conditions where your signal is very weak. You need highs mids and lows in there so people can distinguish your words.

Example 2: Quality vs. Quantity. Example Scinereos. 1: You hear a Ham Radio Operator using a $2000 HF radio on AM CB Radio, and then you have some peaked out super modded galaxy with a 300 watt linear maxed to the hilt. The guy with the CB is making a lot of noise but the Ham Radio seems to be talking through him. Another example is, notice how some radios will "talk over" other radios that are giving a higher signal reading. Why is that? Did you ever notice that someone with an untouched cb radio has less heterodyne when talking at the same time as other cbers. Another words, when cbers on AM talk at the same time a squeal is produced. Have you noticed, if you get two untouched "barefoot radios" talking at the same time, you can often understand them both instead of all the excessive squealing noises? (heterodyne)
Here is another example that will help put this all in perspective. Have you ever heard one of these people with a "super peaked out radio" with their mic turned all the way up get on SSB? They sound horrible. They sound tinny, screechy and like they have a clothes pin on their nose. Distorted and scratchy. This may come as a shock but cb radio operators are known for horrible audio.

What is too Loud? Have you noticed what happens when you turn up your stereo too loud? It does not get any louder, it just starts to buzz and distort. If you were looking at this signal on a scope you would see nice sharp peaks start to level off at the top at a constant. This is called "flat topping". Something can only get so loud before it levels off and goes flat. With a cb radio, what usually happens is that pinched off clothes pin on the nose sound. People can still kind of understand what you are saying, but, it's far from a positive listening experience. If your audio is pleasing to the ear, people will want to contact you.

RFI/TVI: As stated above. Something can only get so loud before it "flat tops". "But it said it's putting more power out on my cb watt meter". Sure it is, but that perceived "power" is not helping you talk further. It's going in your neighbor's phone and TV. Notice how the guy with the stock radio makes all the same contacts as you or more, but they are not getting in to their neighbor's electronics. It's not because you are louder, it's because your transmission has gone unstable. The more unstable the more harmonics. Not only are you producing unwanted harmonics in your transmit audio, but you are also putting out harmonics by way of radio signals.

Get this. Sometimes you will have ham operators complain of cbers talking on the CW portion of 10 meters in the area of 28.000-28.085 Mhz. You have truckers talking there yes, BUT, a lot of the time these people are hearing a harmonic of cb radio channels. They hear this and think "I hear cbers talking on ham radio frequencies". This is not always true. The next time you hear a trucker pass through running 300 watts on a "super peaked out radio" jump up above twenty eight hundred and have a listen. You may hear him clear as day but with considerably less signal. Harmonics. Notice how you don't hear stock FCC Approved cb radios up there producing harmonics. If they did, they would not be on the market. So you have all of these Ham Operators running around chasing harmonics thinking these people are on Ham Frequencies. Once again, some of them are. It's best to tune to the cb band after hearing it to see if what you are hearing is a harmonic. Tune down to cb, if you hear the same voice with greater signal, there you have it.

So how do I get "broadcast audio" on a cb radio that sounds like a proper radio station. Easy answer. Don't pay to get your radio tweaked out, rather pay someone with proper knowledge and experience to "Align the Radio". Some radios are out of tolerance and alignment from the factory. The thing needs to be aligned after it's been switched on for some time and allowed to come up to operating temp. If you have someone align your radio (especially a SSB radio) cold on the bench, when you get home and let in run two hours the frequency will be a bit out of whack, being the clarifier is receive tuning only. The radio needs to be work horsed on the dummy load to get it up to temp and then aligned. Cb Radios are pretty sensitive to temperatures on SSB. They naturally drift a little, but, they will drift less if the radio is up to operating temp and aligned properly. Not "Peaked Out", "Tweaked Out" or "Super Modded". Alignment.

Modulation: As you learned above, your "modulation" (AM CB Radio Term) should be set on a scope with your voice. Have you ever heard those people with a deep voice get on a "tweaked out" radio? They sound like they are talking through their nose via some vibrating wax paper and a paper tube Those low mid tones in their voice are "flat topping" that portion of the audio bandwidth. When this happens the nasty tones override the entire range of the voice. Often turning their mic down will not help as the audio bandwidth is "pinched off" due to a poor "peak and tweak" or misalignment.

Here's another example of poor cb radio audio. Everyone has heard these fly by night cb radio dj's that hold a mic up to a speaker and play music on the air. What do you usually hear? You hear something that sounds like a 50 gallon drum half filled with nuts and bolts rolling down the street. You hear mostly all the tinny high sounds. The more their radio is "tweaked out" the worse it sounds. Now as we learned in the car EQ example above, does it get any louder when you cut all EQ levels and turn the middle one all the way up? No. Anything after "as loud as it gets" is distortion.

How does livecbradio.com do it? Livecbradio.com uses a bone stock Cobra 148 GTL. The "Broadcast Audio" is superb. People have said "that thing sounds like a FM radio station". The Livecbradio.com mic audio on SSB has also been claimed to "sounds like AM". Now don't get me wrong, it does not sound like Amateur Radio Wide-Band SSB, but, it sounds Amateur Shortwave Radio Station Quality. Number one, the key is the radio is not "peaked out". Number two the livecbradio.com TX audio goes through an 11 band EQ and other processing.
Let's say for example we have 300hz-2000hz audio bandwidth to work with. It's not much compared to a hifi or commercial "radio station", but it's enough to sound really good. We have also had reports like "your audio is loud and clear". Is it loud? No, as described it can only get so loud before distortion. It sounds "loud" because you are hearing all frequencies in a dynamic separate fashion in harmony, instead of everything all run together and buzzing. Loudness is mainly an illusion to the ear. You may not hear the bass guitar like you do a regular guitar in a rock and roll band, but, when you remove the bass guitar you can sure tell it is missing. Point being, when you get your radio "peaked out" you are removing some range of audio frequency..

I am not suggesting everyone go out and attach an EQ to the mic line of their cb. What I am suggesting is proper alignment of the radio combined with the right microphone for your voice. For example stock microphones can get a little bassy for someone with a deeper voice. Something like a properly adjusted D104 (crystal microphone) will restore some of the highs in your voice for better sound quality. Now someone with a higher pitched voice can sound too tinny and scratchy on a D104 crystal cartridge microphone. This person might want to select a "Amplified Condenser" style of microphone to restore some of the bass in their voice. The stock microphone that came with the radio is often the best selection for someone with a medium to high pitched voice. The stock microphone is almost always a "non amplified condenser" style.

"But Earl's Cb Shop said I can talk further if I get my radio peaked out". I suppose this would be true if they could turn up your output power without sacrifice to your audio bandwidth. This is most often not the case. The Livecbradio.com bone stock Cobra 148 GTL has talked 50 miles locally. How? Because they can understand the people talking when the signal is very low. They still hear all the range of the voice. If the radio is "peaked out" to the hilt and the audio bandwidth is pinched off, like that EQ with one slider all the way up and the rest down, what are they going to hear? They will hear some amplified scratching noises with what sounds like someone talking through their nose. You are only making power within that range of your voice while the other tones of your voice seem to be gated out, like the removal of the bass guitar example above. Not good. Now it is true that a more tinny and narrow audio signal is usually understood easier at extremely low signal strengths, but, in cb radio it's often overkill and working against you. Number one your job as talker on the cb radio is to make sure your voice is intelligible and people can clearly understand you in all conditions.

What happens when you have really good audio and a transmitter that is in proper alignment? You can talk through and around other stations talking at the same time. Say you have 2 rock bands playing at the same time. They are both playing the same song and both have equal volume levels by whole. The only difference is, one of the band's audio is coming through an oversize toilet paper tube. Without thinking in terms of directional ability of sound, who is going to be heard more clearly? Come to mention it, "talking through a tube" is often another common bad cb radio audio report.

I am not trying to put every cb radio tune up shop out of business. I am merely pointing out the standard of cb radio audio can easily be raised with a little common sense. Cbers need to consider adjusting their transmit / microphone audio like they do the EQ on their car stereo, as opposed to firing up a loud bull horn in a hostage standoff. No I am not some HiFi SSB Amateur Radio fanatic. I have heard wide band audio on a wide band capable receiver that is over the top. Your own personal balance is there waiting for you. The problem is, the people with the most horrible audio on cb radio will probably not have read this far down the page. But, we can all pull together to help raise the standard. The simple car stereo eq analogy can go a long way to these people with their D104's cranked up all the way with a "peaked out radio". Cb gear has always been about influence. When a newbie hears billy bob 718 on a distorted bullhorn with echo, they think this must be the standard. What cb needs is a little more influence to help the stragglers along.

Talk Back: "Talk back" is not your "broadcast audio". What you sound like coming out of a "talk back" speaker has little or nothing to do with how you sound to others. You need to get another receiver / cb to monitor your audio. Listen with the antenna unplugged on the extra receiving unit. Turn things down so your S's sound like ssssss instead of KIRCHSSKWSHSSS!

What would be some great setups for good cb radio transmit audio?
Number one, if I was serious about my transmit audio on cb I would get a "W2IHY" microphone eq. If I could not afford that I would simply put a Home Stereo EQ in line on the mic line of my cb via simple attenuate interface. i.e. 2 resistors. Or I would use a computer soundcard to do my audio processing. In most cases this would probably take an additional DPDT relay or switching to handle this. Since a normal cb mic needs DPDT switching this would be mandatory. i.e. DPDT pinball button or DPDT vox/ptt switching relay. The same can be done for rack gear. In effect all you are doing is making an "effects loop" on the audio and shield wires on the microphone. Two wires going from mic get cut and run to device. The output of that device then goes back in the mic and down to the radio where it was cut. Resistors are then placed in certain areas on the mic line in series and parallel combination(s) to reduce voltages when needed. Example: Speaker output of a sound card going in to mic line is too much voltage. Put 2 simple resistors in line as described for "attenuation of signal". You can find all the diagrams for these things by googling "echolink interface" and "radio to soundcard interface" and things like that. A simple "isolation transformer" is also a good addition to your interface to protect against "ground loops".

If i just wanted a good mic I would get something that matches my voice as described above. To be quite honest I would find something with a powered "electret cartridge". An example of an electret mic is a simple cheap computer mic. They make cb mics with electret cartridges.Examples of electret Ham Radio mics that would work would be the Kenwood MC60 or Icom SM20 desktop mics. Notice how "chat room audio" with people using electret mics is so clean and dynamic. Good bass and good high end without being tinny. An "echomax 2000" has an Electret head, but unfortunately for this style they don't sound all that great on some radios.

You have tons of options to sound great! If you are serious about being on a radio it just makes good sense to do a little work to make sure you sound good. A good rule of thumb would be ignore what is popular and what people are saying. One doesn't have to spend thousands on rack gear to tinker with this kind of stuff. People have been known to sound great running their mic audio through an old realistic voice box they obtained at a garage sale.

If I wanted a sure fire out of the box perfect setup without the fuss I would say "Get a new untouched Cobra 148 with an Astatic D104 m6b handheld microphone. Job Done. If your voice is higher in pitch than most, skip the D104 Handheld Mic and look for an amplified condenser mic. If you speak with a wispy tone and a lot of breathing the stock mic may be your best bet.

HIFI ESSB & HIFI AM Bandwidth on CB Radio? Yes they are out there. There are at least half a dozen extended SSB operators on the conventional sideband cb channels. On channel 6 you have a few wide band AM operators as well. You know, the people that sound like a dj on FM Radio with that heavy bass. The sound of these radios is nothing less than impressive.

Here is some more low buck inspiration. I heard a guy on an old radio shack ssb base station that had a home stereo EQ wired in his mic line. It sounded like a $2000 Ham Radio with the stock microphone. It sounded nice and flat with a nice fat low end with good highs. On SSB you get a little of that low latency attack time with your words using an eq. Your words become very distinctly precise and separated instead of run together. Tight. A $15 Cb Radio on SSB with an EQ on the Mic line sounds better than a new $1500 HF Ham Radio using it's own stock hand mic. Sounds like a far fetched claim but it's true.

OK, here is a touchy subject, MIC DISTANCE. A great percentage of people on the cb sound horrible because of the distance they speak from their microphone. Someone that gets too close to an electret mic (like a computer mic) will make it "PoP". Like a helicopter pilot. People on condenser mics that get too close sound like they are too bassy and muffled. The people that get too close to an amplified crystal mic like the D104 are the worst. You can hear the spit in the side of their lip and every breath and weez they make. These are the people that refuse to turn their mic down no matter how many people tell them. They think in their mind "Oh they want to trick me in to turning down my power". This is why we cbers call it "Modulation". Otherwise known as power to cbers. To turn down your D104 would be a fate worst than death. hi hi. Know how you sound. Another tip, don't speak louder or get closer to the mic when signal conditions change. Getting up on the mic and yelling is not going to increase your ability to maintain weak signal communications.

A word about Linear Amplifiers on cb radio. I have spoken base to mobile 50 miles with 4 watts on a stock radio with EQ. On AM. I have talked all over Europe from Nebraska on SSB using 2-12 watts. (last sunspot cycle) I spoke to Australia, Saudi Arabia, Japan and Africa with 12 watts or less on CB Radio SSB. In experimentation I have made overseas contacts on 1 watt with a simple Antron 99 antenna. My point. Cbers need to worry a little bit more about radio procedures and conduct to prepare for the coming tide of DX. Like last time around the DX will come wash all local cb communications away for years. You won't be able to talk to your neighbor down the street by cb. At times it will get so intense it will even wash out all stateside DX on AM with exception to channel 6 AM. It will be "30db of hash and trash" day and night for years. Only truckers within eye shot will be able to communicate via cb radio. The only real survivors in this will be those on SSB and those with 1000+ watt amps to run on AM. It's going to get nasty. Cbers need to prepare for this or it's just going to come as a huge shock. Buying a big amp to put on your big stick will not help you. Your best bet would be a directional antenna and some decent audio combined with a knowledge of proper radio conduct. People are going to find that an over powered cb that is too loud screaming, "this is billy bob ba lam a lam a ding dong cmon in" is not going to cut it. That sort of activity will just be a small percentage adding to a huge noise floor on the band. No, the point is not to turn CB Radio into Ham Radio. The point is you better be prepared. Your local cb cliques are going down. The days of sitting on channel 19 agitating the truckers will be over for years. That's right, a huge tide is coming to wash all the trash off the cb radio. Only the true die hard cb radio hobbyists and short wave listeners (SWL's) will remain. It will be interesting listening that is for sure. Those cbers not around last cycle have a rude awakening coming. The livecbradio voip program will always be open to communicate with like minded radio people looking for conversation.

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