Troubleshooting mylack of distance, receivng and transmitting.

I highly doubt the radio has any thought whatsoever. If after years of daily talking the radio still performs as well as it ever did what then will you say? So you are saying when an antenna tuner makes a radio 'think' the match looks good it will also be destroying the radio? In mathematical terms explain the difference between a quarter wave length of coax shorted at one end and a parallel inductor - capacitor combination to a TEM sub 00 RF wave at the resonant (identical) frequency of both circuits, and show your calculations. What electrical differences will you see in a coax terminated by A - a highly reactive impedance, and B - a purely resistive load of the same impedance as the characteristic impedance of the coax in question.

 

Gadfly, while everything you say is true....

If you have dealt with installs in big rigs, sometimes the counterpoise isn't there nor correctable. Often (especially as trucks get newer) coax length does indeed play a role in swr when you cannot alter other issues that would correct swr. In many instances the different coax length physically changes the amount of reflected power back to the transmitter, thus saving the radio from overheating/damage/failure.

Yes, it's in essence acting as a dummy load (as some may say) or part of the radiating system (as some say), yet in some cases it's the best you can do while preventing failure to the radio.

OTOH, I suppose the truckers could just use this instead...

 

"Yes, it's in essence acting as a dummy load per se"

Actually the coax becomes part of the radiating system, not a dummy load. Reading the series 'Reflections' by Walter Maxwell W2DU would be useful. In fact I believe required for anyone who wishes to try explaining transmission line theory to another. You can read part of it free at http://www.w2du.com/ , well worth the time and effort. I learned of this great figure in radio from a friend of Mike. Glad I took the time to study the mans work.

 

Corrected, thanks

 

Gasp

Anything bugs me more its cutting coax for a match .......

I know from trying to use antennas on bands that they are not made for like a 40 meter vertical on 75 YES you CAN get it to match HOWEVER replace that vertical with one that is made for 75 and watch what happens ... using the same coax .....

My tuner is a autotransformer in a way you can take a high or low line impedeance and match it to a 50 ohm radio ... yep 1:1 match.

HOWEVER ….. let’s go out 10 miles and see what the other station is seeing depending if your antenna is MATCHED to the feed line or your running a 12 ohm or 200 ohm antenna at the coax feed down a 50 ohm coax then auto transforming it to look like a match ……

Bottom line is which works better ……

 

No bottom line exists if you have not actually done a scientifically controlled test and published your findings. In all the years I have listened to people argue this out none have ever done so. Endless swearing by one position or another while never actually proving they are correct. You need to take the time to read the books by Walt and study what He has to say on conjugate matching. His work has been scientifically tested in the Ham, commercial, and military world, is in use on these levels even today. I think anyone here who holds a firm position without conclusive proof should study the work which is actually published. I know why Mike holds His opinion even though He is not a technician and cannot argue it in terms of theory. He has driven the same model truck for years and has methodically tried every idea I have ever heard discussed. He bought the top line MFJ tuner and as big as it is ran it in His truck. Losing people a couple miles away. Tried over a dozen diverse antenna types and models never finding good results.

Over time through many trials arrived at the setup He keeps trying to explain to people here because using His method He is reaching 15 miles down the road quite easily with a fairly inexpensive setup. His motivation in trying to explain it here is His desire to help fellow drivers. I highly doubt He cares one whit what all the radio people who try to shoot Him down on this board have to say about the subject. His desire is in telling the other truck drivers running similar trucks about a method which makes a dozen miles or better the daily norm for Him. He is out there as I type these words doing just exactly that, talking over 10 miles away to another truck in his rig using the very setup all the people here keep proclaiming is not possible. I know this because He has a cell phone and yes I do have a land line right here by this computer. In His entire career the truck He is in is the worst possible model to get an antenna match while doing great distances. Just as science proves a bumblebee cannot fly even though they always have, He is talking right now with great results using a setup all you keep saying will not work.

You cannot get better data by means other than actually doing a thing and proving to yourself and the person on the other end His setup is working great and He is happy as a clam that finally He can get down the road with His radio. My advise is stop trying to prove Him wrong with opinions not yourself tested nor proven and let Him do what He was trying to do in the first place. That is, helping other drivers find a solution in similar model trucks which works well and does not cost much to implement. The comment I read earlier that He was damaging His radio is erroneous for multiple reasons. To be so doing implies energy as heat being lost in the finals, not getting over ten miles down the road. The radio never fails and never needs repair even though He uses it all day every day. The examples I read about here proving Him wrong all involve radically different antennas in very different situations such as "40 meter vertical on 75", and have no application to the discussion He was trying to have. After you get that 75 meter antenna working on a Cascadia and publish your findings I will consider it.

 

so if my TS-480SAT

AND my Icom 2 Meter radio

Both work good on my 25 foot RG-58 AND my 100 foot RG-8 (LMR-400) AND the radio clubs 600 foot LMR-400 coax? and is showing the same SWR, what does that mean?

 

SO ...... on 10 meters ..... lets use a reasonable band ....

I can take a 440 mhz wip which would look like .01 ohms on a 50 foor RG-58 coax AUTO TRANSFORM it with a magic tuner to 50 ohms and it would work as well as a 7 foot Hamstick at the end of the same coax MATCHED to 50 ohms at it's base and feeding the coax with a 1.1:1 match

The point is in some cases you CAN play with matching useing anything you want however is that the best way to do it

GOOD EXAMPLE ..... The G5RV antenna with ballance feed line ( 450, 300, 75 ohm ect ) YES it looks great across a wide range of bands LOW SWR ... very nice however lets try a 40 AND 20 AND 17 AND 12 AND 10 meter dipole at the same hight feed with RG-58 any length wanta bet who will win ?????

I'll leave cutting coax to those who who to play that game .....

 

"SO ...... on 10 meters ..... lets use a reasonable band ....

I can take a 440 mhz wip which would look like .01 ohms on a 50 foor RG-58 coax AUTO TRANSFORM it with a magic tuner to 50 ohms and it would work as well as a 7 foot Hamstick at the end of the same coax MATCHED to 50 ohms at it's base and feeding the coax with a 1.1:1 match"


My first thought is continuously comparing apples and oranges while choosing unreasonable extremes upon which to base your suppositions is inherently dishonest. Or do you really think matching a sewing needle to talk on 80 meters is relevant to the discussion. This and "it would work as well as a 7 foot Hamstick" using points of contention not germane to the claims Mike was making further amplifies the concept of not understanding, or misrepresenting, or simple dishonesty, you pick which. Nowhere did I read a claim by Mike of anything related to the conditions you are trying to use in your refutation of the concept. I myself think if we assume you know theory then dishonesty is the most probable cause of the words you write. This leaves open the question, are you cleverly picking comparisons in the perpetration of a lie or is it that you really don't know what you are talking about nor what was being discussed. Saying 'lets use a reasonable band - 10 meters, and then using an extreme jump to 440 for the antenna, clearly indicates you cannot understand the concept so the only way you can discuss it is to lie until the masses believe it is true.

"so if my TS-480SAT

AND my Icom 2 Meter radio

Both work good on my 25 foot RG-58 AND my 100 foot RG-8 (LMR-400) AND the radio clubs 600 foot LMR-400 coax? and is showing the same SWR, what does that mean?"

It means a resonant resistive situation is being seen at the antenna feedpoint by the transmission line and length would only be applicable in terms of loss. It also means you have no understanding nor concept of the point in discussion which is conjugate matching in coax which only sees highly reactive components at the feedpoint.

Whether either of you are approaching the topic from a perspective of ignorance or dishonesty or both, there is no common ground to hold a valid conversation so why bother.

 

NO I HAVE WORKED FROM 1750 meters ( 160 KHZ ) to 96 GHZ ..........




The only way to match an antenna to coax is to match the antenna to the coax NOT play with the coax to make the antenna work ..... YOU push the point that playing with coax and placing it in the radiation part of the antenna system is as good as doing it right and making the coax act as it should that is MOVE power from the radio to the radiator .... AKA antenna

If your theory is correct why bother with cutting an antenna to a given length just toss up a 6 inch wire and go to it on 3.75 MHz ...... Sorry but in almost 50 years of being licensed I have tried the coax route inserting stubs of 75 ohm coax ( which does work better ) ugly balums also do have a effect but nothing beats just biting the bullet and tuning the antenna to correctly match the coax AT the ANTENNA feed point.

Look at the “Ringo” antennas SIMPLE match an auto transformer built in at the base ( feed point ) YEP a ½ wave antenna very high Z and you can tune it down to under a 1.5:1 match no problem it does not care what you do with the coax ……

We are not talking about 1:1 matches all you got to do is change anything and that just is not going to happen or stay that way but go to it and tell the truckers that cutting coax is the way to match things like I said the only cut I make on coax is how long I need to get it from the antenna to the radio.