Coax Length Question

Mikes point all along relates to the near impossibility of obtaining a good ground in the Cascadia He drives. So He does the best He can with what He has.

 

Does it not have a steel frame?

 

Too bad you don't read the posts! I understand all that and said so! But "fixing the antenna" is not always an option. To go by what you "experts" say if I can't get a low enough SWR to safely use my radio, then I shouldn't use my radio!!! A longer/shorter coax can overcome a mismatch to where you can safely use your radio. Put me down and make fun of my lack of knowledge all you want, but I'm right cause I've proved it in practice many times. I've talked to a very good tech and he has tried to explain to me the technical side of why a longer coax works sometimes, but I can't argue it with you because of my limited knowledge. I'm not a tech or engineer and can just barely use a ohm meter. But I've installed and used many a CB radio and have never damaged one because of too high SWR! Something about reactance and so forth......you can go ahead and impress everybody with your knowledge and explain what i can't if you want to. But no matter, what you say, when perfection is not present, you can overcome a bad match with coax length to get you by. That is the only point I'm making.

 

How many mobile installs have you done in todays trucks? You are comparing apples and oranges my friend!

 

No it is all plastic smart ###! Come give it try on these new trucks then give us your wisdom! I love how people who have never done/tried something think they know all about it!!

 

Thanks for the insulting comments, you are such a asset to this board! I fully understand that using the coax to lower the SWR is not the correct way to do it! But sometimes it is the only way to get it done for the moment. I have stated this many times and thought I made it clear. It seems to me you "experts" can't wait to impress us drivers (I'm not impressed by the way) with your superior knowledge about radio. Too bad most of you don't seem to have any practical experience when it comes to truck installs! You can sure quote the "experts" though!

 

I'm not sure I understand all you said, but is sounds arrogant and condescending to me. When is the last time you did an install in a late model truck?

 

I was responding to a post where the writer was being arrogant and condescending. (And no, Heaviside did not remove quaternions from Maxwell's equations because "engineers and students were too stupid to understand the math". He converted the equations into vector calculus because it was a new form of math that he (co-) invented.)

I know that you can make the radio "see" a low SWR by manipulating the coax length. Nobody here is disputing that. And while I can see that doing so may be the most expedient way to do it, there are usually better ways to do so.

 

how is it apples and oranges? as far as doing installs on modern trucks, buy your self a bird perch and mount your antenna to that. take out of of the mirror bolts and screw in the BP to that hole. might need some extra grounding but then you can mount the antenna to the mirror. run your own good quality coax and you should be all set.

 

I was trying to be nice to the memory of Heaviside. He Himself did not understand topologies in higher dimensions. A subject not known or understood until quantum mechanics took off in the last 50 years. He believed in at most 4 dimensions in His understanding of physics. Even Einstein had trouble as exemplified by His famous quote "God does not play dice with the universe". So He struggled with the dilemma of introducing or not introducing His cosmological constant, having no knowledge of the as yet unknown dark energy and dark matter. Invisible yet there in amounts greater than all visible matter and energy in the universe. By using tensors and vectors alone to describe EM with His alteration of the calculus first invented by Newton, Heaviside in effect 'hid' much information from the understanding of RF engineers as was taught from then on. Try to get one to fully explain all aspects of the Poynting vector.

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

One may ask how does this apply to a radio conversation? Only when you understand how the physics that governs the universe operates, will you understand those same physics govern electromagnetic propagation. A subject that governs yes even CB radio. Similarly one may wonder why electrons move through wire at a velocity slower than molasses, yet the power flow is nearly the speed of light. Look up electron drift velocity. Or ask why a photon annihilating itself to produce a pair of electron and positron results in two particles which exhibit quantum connectivity, something Bell struggled with in His famous inequality. The very same laws governing these esoteric aspects in physics govern the energy flowing in your coax so no, none are gurus of RF engineering until they have a handle on this. In M, and string theory one must know without at least 11 dimensions no understanding of the true nature of reality will be achieved.

I only spoke in the first place as I took your dummy load comment to Mike to be an insult to Him, realized only by those with better than average understanding. So you are not the innocent nice person you try now to convey.