want to do it myself

"As a professional antenna engineer with the Astro-Electronics Div of RCA, I published a seven-part article in QST in the 1970s highlighting many misunderstandings concerning transmission-line theory and techniques that were prevalent in both the engineering and amateur communities. The most prevalent misunderstandings centered around the use of SWR and impedance matching between the transmitter and feedline, and how the mismatch at the junction of the feedline and antenna can be compensated with an antenna tuner, thus providing a conjugate match at the junction.

I clearly see that this is done WITH A TUNER! NOT COAX!

 

As most know my eyes are failing and I dont see well but that said did I read right that you got a award from CQ? IN fact I go to the retena doctor again tomorrow so maybe I missed you or have the wrong list ?

http://www.arrl.org/news/view/em-cq-em-announces-2011-hall-of-fame-inductees

 

Won't waste more time talking to either of you. I copied words he wrote and a tuner used in CM was the topic we were discussing at the time. I was using the text to show who he is and had hoped you would go study his writings on CM. Bruce cannot tell where quotes end and is out searching to prove whether or not I won some award having nothing to do with me. The link he gave is all I need to know he has no interest in learning anything he is spending his time trying to catch me in a lie I did not tell because he confused the text. He cannot tell whether I was talking about me or was Walt talking about himself. He cannot read what I posted, needs his glasses, yet reads well enough to type and research online and post not knowing what he is saying. Point being it shows where his priority is and it has nothing to do with having an intelligent discussion. No different than when he looked up my call, posted the info, saying I could not really be a ham. It was all about trapping a person not reasonably listening to that person. Motivation is key. Neither of you bothered to read the text Walt wrote in the links I gave on the subject. Neither of you are trying to study or learn on the subject of the conversation, it's all about the argument with you and nothing else. You refuse to look at anything else and refuse to even consider that millions of truck drivers have had their CB run more efficiently when they use a certain length of coax. Nor do you consider why manufacturers who hire degreed people who put your education to shame for some weird reason specify coax lengths in certain applications having nothing to do with how far the radio is from the antenna. If there was any hope of you learning anything you would at least study the subject and look at the facts. Problem is none of you have any interest in doing so. Nor could you explain why a shorted quarter wave of coax or an open quarter wave have properties identical to discrete RLC circuits since in your minds no length of coax is different than any other no matter what the initial conditions. You would not read engineering texts called college text books which talk about a range of impedances between nodal points in a transmission line. Nor have you bothered to study why a coax length would act differently when reactance was present in the system. So post till your stupid I for one no longer care.

 

Interesting ....... Glasses don't fix loss of sight which is why I use larger type. I ASKED YOU A QUESTION since what you said COULD have been read several ways.
AGAIN tuning coax does not fix the problem tuning the antenna DOES I am well aware that coax is a one continues L/C/R circuit but to assume all coax are the same and cutting them to a given length to match anything short of dipping the coax with a GDM is false.

There is not ONE piece of cut for a match coax in my shack and my beams were matched with a commercial power divider ....and it is NOT 50 ohm coax ......

Antenna tuners work wonders .......

 

What I said was outside of the quotes.

"to assume all coax are the same and cutting them to a given length to match anything short of dipping the coax with a GDM is false."

Since I never made this statement you must be talking to the wind. Or yourself since it IS your statement. My point was drivers through trial and error have found that experimenting with line length allows them to get their station working better. If you are talking about my mention of 18 feet that was not my statement. I was merely pointing out what all the manufacturers have said. You are aware that terminating the coax in a lower impedance say zero ohms creates a parallel resonant circuit 90 degrees out. So you can assume terminating a coax with an impedance lower than the coax figure, say a 36 ohm CB whip, will after the first mirror image from the antenna towards the generator create a reactive impedance depending upon the electrical degrees out. Under these conditions your coax length has no significance statement is in itself a statement without significance. Especially since this is the real world condition in every truck on the road.

Like I said, no longer really worth discussing.

 

O.K. haven't read past this post I just quoted yet, but I want to point out something. In theory you and Bruce are correct. But I put radios in different trucks every week. Not all the same models. Nothing is perfect in these newer trucks. Different length of coax will change your SWR allowing you to be able to use the radio. I see it all the time. I'm not stating something I read in a book or something somebody has told me, I see the proof of this every single week (well almost every single week). I know it is an antenna problem, but you can't always do what is necessary to get the perfect conditions so that any length of coax will work. If you actually did these installs and tried all the options I have, you would know this!

To all you drivers out there, this is fun/interesting to read, these guys are all more educated about radio than the average truck driver. AB7IF has more experience/knowledge about CB radio than his current adversaries, but don't take my word for it, read what he says. However, take it from another driver who slip seats and has to install a radio almost every week, in different model trucks, that length of coax can indeed make a difference in a SWR reading and whether or not it is safe to key up your radio. Granted, if you have to use different lengths of coax to get a good SWR, then there are other problems, but sometimes that is the only fix you have which will enable you to safely use your radio. Don't believe me????? Get around a newer truck, (especially a newer truck) put in a radio, check the SWR with different lengths of coax and see if it changes/improves. Then you can come back to this thread and tell the more knowledgeable ham guys here that they need to get out and experiment more and quit quoting from the book!!!!

P.S. Calling names and trashing Russ isn't making your point either. I'm still watching .............

 

Then you can come back to this thread and tell the more knowledgeable ham guys here that they need to get out and experiment more and quit quoting from the book!!!!

And what do you think that he's trying to do? Saying read an article by Walt. Mike we all have our own views. And some of us quote facts. Some ??? Maybe you need to read more books. I would put my money on the books being correct first even if I was quoting them. If you search you'll find the truth. And with that I 'll add this anyone can trust whatever they so choose.

 

WOW
Can we please get back to the topic at hand?
I have a Cobra 50 year Anavresry Cb Radio(wich I love BTW) that is BONE stock in a 2009 Volvo, It wont broadcast more than 50-75 ft I can hear really well from a distance I can hear all the skip shootin ^^%%$#@# on channel 6 too.I will do some Mods in the future but not now. Anyway, All the radios in the truck run thru 1 CB anntena, The am/fm cd, the volvo gps, and the CB.
And it doesnt work worth a Sh&T
SOOOOOOO what "I" was thinkin was to disconnect the coax at the back of the CB and run a NEW antenna on the pass side and new coax. I was thinkin a new Wilson 2000 350W with some Radio shack coax(9ft) would that be ok?

 

The Wilson 2000 would be a good antenna. I wouldn't run Rat Shack coax though. Get you some good RG8X.

 

If I DO, I will find the truth!! I'm not saying the books are wrong. I'm saying on almost all trucks, especially the new ones, a different length coax can make a difference in whether you can safely use your radio or not. I know, I see it almost every week!!!