Question:
Fact:
if your SWR is 3:1 or 1:1 the receiving station will not be able to tell the difference.
Most cb's that are soild state if not all like to see a SWR of 2:1 or less. If it is more the power is simply folded back.
A swr of 3:1 is only 75% effecint. So what, every time you increase your power four times the recieving station see's a 1 s unit increase or 6 dbi. The human ear can really only notice a 1 s unit increase but most likley you will only notice that on your meter.
s meters may be accurate at say s5 and inaccuarte at s7 Even the 3000. dollar hams rigs are know for this.
Bottom line if your match (swr) is less then 2:1 than your rig should put out full power.
But remember,
just becaues you have a good match (52 ohms) does not mean that your antenna is matched.
It just means the radio is seeing 50 ohms and is happy. It could very easly be that 95% of your power is being absorbeb in ground loss and only 5 % is being radiated out through the attenna, not uncomman at all. Especially as you go lower in frequency. As your coax becomes old,bad and weatherd it will become a good dummy load and your match will keep getting better and better but it is only aborsbing the power.
Generally everything behind your antenna port is the antenna system and it all works together.
Hope this helps a bit and does not confuse to much.
Best Regards, Dan


Last edited by GuitarDan on Mon Dec 08, 2003 8:48 pm; edited 1 time in total

Answer:

I tend to agree with you.
Many drivers are not interested in reaching MARS, just over the median sort of speak. I'm one of those.
My coax is a stock car coax, 2004 Columbia, should be replaced but snaking a new one through the mirror tubes and car body makes that a seemingly impossible task.
Wilson makes a quality co phase that has the ends of the cable flush, I'm guessing you could snake it through the tight channels from the cab through the mirror tubes???
I don't want wires hanging or running out in the open in the cab. That to me looks like hell.
My SWR fluctuates from 1.5 to almost 3. It fluctuates, even on different HWY locations from state to state and/or time of day/night.
Overall, I can get out about a mile. That's plenty for me. I can hear further than that. As it is, I have the CB turned off 90% of the time. I'm not interested in listening to stressed out drivers venting their problems mile after mile 24/7 on the CB....
Last edited by dak1 on Sun Dec 07, 2003 10:37 pm; edited 1 time in total

Answer:

Originally I tend to agree with you.
Many drivers are not interested in reaching MARS, just over the median sort of speak. I'm one of those.
Yep me to.
My coax is a stock car coax, 2004 Columbia, should be replaced but snaking a new one through the mirror tubes and car body makes that a seemingly impossible task.
an ugly job
Wilson makes a quality co phase that has the ends of the cable flush, I'm guessing you could snake it through the tight channels from the cab through the mirror tubes???
with a little luck.
I don't want wires hanging or running out in the open in the cab. That to me looks like hell.
neither do I
My SWR fluctuates from 1.5 to almost 3. It fluctuates, even on different HWY locations from state to state and/or time of day/night.
That's the whip, whipping.
Overall, I can get out about a mile. That's plenty for me. I can hear further than that. As it is, I have the CB turned off 90% of the time. I'm not interested in listening to stressed out drivers venting their problems mile after mile 24/7 on the CB....
Overall I tend to agree with you as well.

Answer:

keep listening to dan and a mile of transmitter range is all you'll ever have. car drivers should drive cars and car drivers wanting information about communications systems should get their info from those who know what they're talking about.
here are some tips from a reputable antenna manufacturer (firestik) and a radio technician (not some car driver or "cb guy") who collectively have over 60 years of experience in working with antenna systems........read carefully!
Last edited by 228 on Wed Dec 10, 2003 10:16 am; edited 1 time in total

Answer:

Your links, 228, are to your own homepage and merely display your concept of RF technology.
There are plenty of websites available which actually explain VSWR, how it is measured (no, not with a meter) and the role it plays in RF transmission. Anyone with a desire to know more about VSWR would do well to visit those websites and not the websites of CB/CB antenna manufacturers/CB "technicians".

Answer:

Originally keep listening to dan and a mile of transmitter range is all you'll ever have. car drivers should drive cars and car drivers wanting information about communications systems should get their info from those who know what they're talking about.
here are some tips from a reputable antenna manufacturer (firestik) and a radio technician (not some car driver or "cb guy") who collectively have over 60 years of experience in working with antenna systems........read carefully!
I would like to suggest that one should listen to a antenna manufacturer objectivly and veryify what is claimed and more often then not you will find it to be truth that had been very well strecthed. All though I, do not have a PHD in rf radiation I think that we can benefit from those who do and have spent there life in the field.
There is no shoratge of good information on the subject if you wish to obtain it.
I think we can do better then "and a radio technician (not some car driver or "cb guy") who collectively have over 60 years of experience in working with antenna systems"
Best Regards, Dan

Answer:

dak1 wrote:
" My coax is a stock car coax, 2004 Columbia, should be replaced but snaking a new one through the mirror tubes and car body makes that a seemingly impossible task.
it is "seemingly impossible" without the proper equipment. it's a 2.5 hour job with a Stream Line Steel Fish Tape and simple hand tools. i've done quite a few of them in the last 30 years.
Dan, John C.,
"Your links, 228, are to your own homepage and merely display your concept of RF technology."
Yes, they are on my website, so what's your point? No, my concept is not the only one presented here, which would be obvious to anyone who can read. here are a few of the authors presented on my site. in most instances, my "concept" is no different than those of the authors represented below. you'll notice there's no "Guitar Dan" listed, LOL.
"Coax Theory"
by Russell E. Clift, AB7IF
"M Walter Maxwell"
"FireStik Website"
"Institute of Electrical and Electronics Engineers"
"John C. Fakan, Ph.D."
"Ken Miller, W2AF"
"Terman's Radio Engineers Handbook, 1943"
"QST Technical Department"
Further Reading
"Antenna Engineering Handbook by Jasik"
"Antenna Theory: Analysis and Design, Second Edition"
"Antenna Theory and Design, Second Edition"
"Practical Antenna Handbook"
"Antennas"
you already are getting the "benefit from those who do and have spent their life in the field."
for authoritative information on the subject, you will be hard pressed to do better than this.
228
292 Radio Shop / FireCommunications Network
with the various imperfections of the vehicles involved and the limited amount of transmitter power available, SWR definitely does matter. or to put it another way, it matters that we have a correct understanding of swr and realize that there are many other parameters involved in an efficient antenna system, swr being one of many. the big joke on most of us is that swr is only a small part of the picture. a given antenna might very well have a flat swr but if (for example) the radiation resistance is on the order of only a few ohms (or a few tenths of an ohm) then the % of radiation efficiency is extremely low, almost directly proportional to the smaller overall size of the antenna with respect to its physical length in terms of operating wavelength. while the % of loss due to swr is non-existant the loss created by excessively low values of radiation resistance plays a much larger role in the overall operation of the antenna by comparison. what's the difference? it's the difference between dak1 talking and hearing for distances of a mile and talking and hearing up to distances of 25 - 50 miles. big difference.
Last edited by 228 on Thu Jan 15, 2004 7:58 pm; edited 1 time in total

Answer:

Yes, they are on my website, so what's your point?
My point is quite simple: Your website only reinforces your point of view and to use it as a “reference” is meaningless. It’s just you repeating yourself.
it matters that we have a correct understanding of swr
That is correct and we begin by using correct terminology; what you refer to as SWR is correctly known as VSWR.
realize that there are many other parameters involved in an efficient antenna system
An antenna is an antenna and it’s efficiency, or lack thereof, is a function of design and the manufacturing process. There is no “antenna system” in the CB world of cars. There is a receiver/transmitter (the CB radio), a transmission line (coax) and an antenna.
swr is only a small part of the picture
You are 100% correct, sir.
a given antenna might very well have a flat swr but if (for example) the radiation resistance is on the order of only a few ohms (or a few tenths of an ohm) then the % of radiation efficiency is extremely low, almost directly proportional to the smaller overall size of the antenna with respect to its physical length in terms of operating wavelength. while the % of loss due to swr is non-existant the loss created by excessively low values of radiation resistance plays a much larger role in the overall operation of the antenna by comparison.[/
This is pure gobbledy-gook. Radiation resistance? It is to laugh.
I’ll give you a chance to prove your expertise, 228. Just answer this one question. Since we all know that VSWR (Voltage Standing Wave Ratio) is the ratio between transmitted power and reflected power in a transmission line, explain how that RATIO is determined, and displayed, by a meter? Thanks for your time.]
Last edited by John C. on Fri Jan 16, 2004 12:12 pm; edited 1 time in total

Answer:

radiation resistance:
the resistive component of the impedance of a radio transmitting aerial that arises from the radiation of power. no gobbledy-gook here, just variables that you have no knowledge of.
here's another link you probably won't read.
you babbled:
"There is no “antenna system” in the CB world of cars"........
yes, there is. a phased pair of identical antennas is an "antenna system". (dual or co-phased) furthermore, when you buy an antenna you're only buying "half an antenna" (unless it's ground independent) because the "other half" is the vehicle body surface over which it is mounted.
i've been using swr meters, l/c network analyzers and Xl/R/Xc noise bridges for years. if you want an explanation of swr bridge operation try a search engine. i have nothing to prove to you nor can i here in this forum. it's readily apparent that if you're not familiar with a simple term such as radiation resistance and its application in understanding antenna design and performance then we can go no further here. for over thirty years i have earned the trust of those i work for by delivering quality and performance. if you want proof of that just stop by and see me. you're welcome for the time.
228

Answer:

radiation resistance:
the resistive component of the impedance of a radio transmitting aerial that arises from the radiation of power. no gobbledy-gook here, just variables that you have no knowledge of.
The resistive component of impedance is not affected by the “radiation of power”. On the other hand, the capacitive and inductive components are frequency sensitive. The term “radiation resistance”, as used in your original rambling “explanation” is, indeed, gobbledy-gook.
a phased pair of identical antennas is an "antenna system".
I should have known that you would bring that up. If you want to call a pair of omnidirectional antennas coupled together in a haphazard manner an “antenna system”, I’ll agree in the same sense that a couple of bent coat hangers coupled together with speaker wire is an “antenna system”.
if you want an explanation of swr bridge operation try a search engine
I have no interest in an “explanation of swr bridge operation”. This is what I asked for:
“Since we all know that VSWR (Voltage Standing Wave Ratio) is the ratio between transmitted power and reflected power in a transmission line, explain how that RATIO is determined, and displayed, by a meter?”
What I’m trying to determine is whether or not YOU know anything about VSWR or are just parroting mis-information gathered from various sources.
I have nothing to prove to you nor can i here in this forum.
It is incredibly easy to “prove” your knowledge “in this forum”. You can either provide an explanation or you can’t.
for over thirty years i have earned the trust of those i work for by delivering quality and performance.
Considering that CB work is relatively low-tech and that the vast majority of CB users are car drivers (virtually none of whom are electronics technicians), anyone with even a rudimentary understanding of electronics can survive in the industry ad infinitum. Doing so falls under the category of “ in the kingdom of the blind, the one eyed man is king”.
That’s not to say that you’re not a good CB tech or that your customers aren’t satisfied with your work. I merely object to the “if you can’t dazzle ‘em with brilliance, baffle ‘em with BS” technique that you bring to this forum.
Last edited by John C. on Sun Jan 18, 2004 2:55 am; edited 1 time in total

Answer:

oh well. all I know is that Jack worked on my radio and it TALKS like never before.
(crank up the power) CAN YA' HEAR ME NOW

Answer:

hey Jeepers, how's everything?
hope you're staying busy out there! good to hear from you.
228
Last edited by 228 on Sun Jan 18, 2004 8:54 pm; edited 1 time in total