CB settings

[99chevytahoe]

I have had a cobra CB for quite some time now. It is the one of the fancier models that has the knobs for SW CAL and a few other things. I have tried reading the manual but I can't make sense of any of these settings. Can anyone help me on what will get me the best range.

Thanks in advance,
Merry Christmas!

here are some pics of the cb (i have since changed my setup btw)
http://www.radioreference.com/forums/showthread.php?t=87484

 

[SCPD]

You don't specify whether it is base or mobile, but regardless, the only legal thing that can be done to a CB radio to give effective range is a good antenna. Amps are illegal for use in the CB spectrum.

 

[zzdiesel]

The mobile CB is either a Cobra 29GTL or a 148GTL

 

[N_Jay]

Set them all to the middle.

Then adjust each a little up or down while in a conversation asking how it sounds on the other end.

I think they should all be labeled, and if the function of any is a mystery to you, tell us (by name) which one, and I am sure you will get all the help you need.

 

[99chevytahoe]

Set them all to the middle.

Then adjust each a little up or down while in a conversation asking how it sounds on the other end.

I think they should all be labeled, and if the function of any is a mystery to you, tell us (by name) which one, and I am sure you will get all the help you need.

thanks, ill give that a shot

and i dont want to add an amp or anything, i just wanted to get the settings where they need to be and i have a 5ft. firestick ant.

 

[iMONITOR]

It sounds like you might be referring to the SWR (standing wave ratio) measurement/tuning. This has to do with how well your antenna and coax are matched to your transmitter, so that you get the maximum signal power out of the antenna. Ideally you would want a 1:1 ratio, but that will probably never happen. With CB, if you can get it down to 1.5:1 you're doing good.

This link provides a more detailed explanation:
http://electronics.howstuffworks.com/question490.htm

 

[whacker]

A 5 ft. Firestik, when properly mounted, cabled, and tuned, ought to give you a very good SWR reading all across the 40 channels. That used to be one of my favorites.

 

[Highlander_821]

This forum is a great source for CB radio info: http://www.worldwidedx.com/

Also, www.cbtricks.com

 

[coldbricks]

I have a few CBs. Everyone is totally right about the SWR ratio. It should probably never exceed 3:1 (anything higher can start ruining stuff) and anything less than 1.5:1 is great. The interesting thing about CB is that it is AM. Without going into a lot of physics, AM is a different type of 'encoding' if you will and behaves different than FM. It has some great advantages and some horrible disadvantages, too. One of the main advantages is range and the ability to modulate for more power. In other words, you can push the input of the transmitter (the CB) and actually increase output watts. This is known in the CB world as 'swing'. A CB that can 'swing' is one that has a large dynamic range. That is, on a dead key (a dead key means no audio going into the microphone) it may give out 4 watts PEP. However if you shout into the thing it might go up to 70watts...this might equal great range, a screaming radio!

On the dark side of AM, it is very prone to interference, so much so that weather can render CB useless. The same phenomenon that can enable you to talk to cuba may also make it impossible to talk to your neighbor. CB 'conditions' as they are called are constantly changing and never consistent...BUT. This is what makes CB so interesting...FWIW, there are people who can tune your radio so it can swing more. There are even swing kits, but I'm not going to go into the legality of them, thats up to you to research! Hope this helps Happy CBing!!

coldbricks

 

[W6KRU]

It has some great advantages and some horrible disadvantages, too. One of the main advantages is range and the ability to modulate for more power. In other words, you can push the input of the transmitter (the CB) and actually increase output watts. This is known in the CB world as 'swing'. A CB that can 'swing' is one that has a large dynamic range. That is, on a dead key (a dead key means no audio going into the microphone) it may give out 4 watts PEP. However if you shout into the thing it might go up to 70watts...this might equal great range, a screaming radio!

coldbricks

When I was in HS I worked part-time at a shop that worked on vhf/uhf and CB. We had a nice service monitor that we could use to monitor the output of radios on a scope. CBs with boosted audio had ugly square topped output with plenty of splatter outside the proper frequencies for the given channel. If you play with CB much, surely you've heard examples of this.

The wattage gain with increased modulation is easily shown with a peak reading meter. An averaging meter will show a different result. What good is screaming into the microphone? You can turn up the mic gain or talk louder into the mic at a closer level. Same thing. Intelligibility is usually increased by backing off the mic and speaking softly so your mic amp doesn't "flat top" which causes distortion.

I have full control of the mic amp on my HF rig with DSP processing as well. For best results the controls are usually middle of the road.

 

[zz0468]

I have a few CBs. Everyone is totally right about the SWR ratio. It should probably never exceed 3:1 (anything higher can start ruining stuff) and anything less than 1.5:1 is great. The interesting thing about CB is that it is AM. Without going into a lot of physics, AM is a different type of 'encoding' if you will and behaves different than FM. It has some great advantages and some horrible disadvantages, too. One of the main advantages is range and the ability to modulate for more power. In other words, you can push the input of the transmitter (the CB) and actually increase output watts. This is known in the CB world as 'swing'. A CB that can 'swing' is one that has a large dynamic range. That is, on a dead key (a dead key means no audio going into the microphone) it may give out 4 watts PEP. However if you shout into the thing it might go up to 70watts...this might equal great range, a screaming radio!

You have some SERIOUS misconceptions as to how amplitude modulation works. I would suggest you read up on it, if for no other reason than to not post these misconceptions for others to 'learn'.

 

[N_Jay]

You have some SERIOUS misconceptions as to how amplitude modulation works. I would suggest you read up on it, if for no other reason than to not post these misconceptions for others to 'learn'.

I was going to post something similar (but not near as tactful):twisted:

http://en.wikipedia.org/wiki/Amplitude_modulation

 

[trace1]

However if you shout into the thing it might go up to 70watts...this might equal great range, a screaming radio!

Have you taken the following test???

CB (11Meter) Operator's Exam

This exam has been compiled with a set of the Basic and Advanced question bank for the CB (11Meter) Operator Exam. The passing grade for this exam is 70%, however, a score of 85% or better will earn the operator his or her Basic qualifications PLUS his or her Skip Land privileges. As with all exams of this nature, a good understanding of CB protocols and practices are essential in keeping the hobby at the level of professionalism that befits all operators. Any individual found cheating will automatically be given a failing grade, and will not be eligible to write for a six month period. It is recommended that users who fail use that six month period to study hard before re-testing. Repeat failures will be disqualified from any further testing. We are a group of professional operators that do not tolerate those who wish to tarnish such an illustrious hobby.

SAMPLE QUESTIONS:

4) If DX conditions become difficult, to improve your chances of contacting that skip, you should:

A) Yell louder into your microphone
B) Kick on your boot and pump out more whiskeys
C) Both A and B
D) Complain that the skip station has "no ears" and stop trying to make contact

8) If there is more than a couple of stations shooting skip on a channel and you wish to make a few contacts yourself, you should:

A) Shout your handle louder and more frequently so as to be heard first
B) Pay no attention to the other operators on frequency and just step all over them
C) Kick on your boot and yell into the microphone, so that you can get the mall down
D) Complain profusely that no one else is giving you a chance and they are hogging the channel


30) To make your handle more legible to the other station, you should:

A) Shout louder into the microphone
B) Turn up the mike gain
C) Shout BREAK BREAK BREAK and then give your handle
D) Very slowly and loudly speak every letter like a military radio operator

 

[kb2vxa]

"Kick on your boot and yell into the microphone, so that you can get the mall down."

Shopping at the mall is just a bit different than dropping the maul. See? I told you CBers can't spell. That having been said just follow the crowd, crank everything to the max so when your voice sounds like it went through a cheese grater and your signal spatters across the band everybody's happy. CB is for having fun and fun means cheesing everybody off so you'll eventually have the ultimate CB experience, the midnight antenna party.

 

[N_Jay]

My Power Mic goes to eleven!

 

[W6KRU]

My Power Mic goes to eleven!

Can you imagine the result if this mentality was applied to a proper HAM station? Some of the settings would be kinda like the old joke about putting someone in a round room and ... How do you maximize audio DSP rolloff for max?

 

[coldbricks]

Hi all, I understand the basics of AM radio. However, in the CB world, 'swing' is definitely a term that is used a lot, and the market for 'hot' and powerful mics is definitely real, as are modulation/swing kits. Some of them sound fantastic, too. Lowering the carrier level and increasing modulation is a CB trick that has worked for me. I get out about 90 miles. Just my $.02

 

[N_Jay]

Hi all, I understand the basics of AM radio. However, in the CB world, 'swing' is definitely a term that is used a lot, and the market for 'hot' and powerful mics is definitely real, as are modulation/swing kits. Some of them sound fantastic, too. Lowering the carrier level and increasing modulation is a CB trick that has worked for me. I get out about 90 miles. Just my $.02

AM is AM.

There is not much magic out there.

Swing is a popular term used by CBers who don't know much about radio.

If you overdrive an AM transmitter you get over modulation and splatter.

You may be able to tailor the audio to sound (somewhat) good on channel, but you will still be throwing trash across other channels.

 

[coldbricks]

AM is AM.

There is not much magic out there.

Swing is a popular term used by CBers who don't know much about radio.

If you overdrive an AM transmitter you get over modulation and splatter.

You may be able to tailor the audio to sound (somewhat) good on channel, but you will still be throwing trash across other channels.

this is all very true. However, it is also very true that basically none of the CB radios on the market achieve 100% modulation. I used to hook them up to scopes with a buddy of mine to prove it to people who bought them. So in other words, there is a whole range of usable modulation that is NOT going to overdrive and blow the finals...

 

[eorange]

So in other words, there is a whole range of usable modulation that is NOT going to overdrive and blow the finals...

Overdrive and "blowing the finals" are not necessarily the same thing. You can do the former and throw garbage all over the airwaves, as N_Jay pointed out, and not be anywhere close to blowing the finals.

You would do well to pick up a copy of the ARRL "Now You're Talking" books (General Class) - even if you have no intention of becoming a ham - and read up on emission types, modulation, and ERP.