Grab a Wilson 2000, some good coax, and mount it on the mirror arm. Adjust SWR's via swr meter and get to talking. It's not that complicated..
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Best Moblie Antenna for OTR Truck
- Thread starter ctvanover
- Start date
They were mechanical engineers though. They didn't seem to have a little man that followed them around to make introductions for them and make everyone aware of their accomplishments. Maybe he got left in the car, maybe out getting coffee or something.
Is a sidekick included in the cost of the degree or did CTR have to hire you through a temp agency? Kind of like how all good CB techs get a rabbiporkchop of their own.
Is a sidekick included in the cost of the degree or did CTR have to hire you through a temp agency? Kind of like how all good CB techs get a rabbiporkchop of their own.
Lmao. ..... give me some more.
This is very good information.
http://owenduffy.net/antenna/m40/alhfv.htm
http://owenduffy.net/blog/
This is very good information.
http://owenduffy.net/antenna/m40/alhfv.htm
http://owenduffy.net/blog/
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CTR
This is partly why I get a hoot out of reading tuning for low reactance is better than tuning for low SWR. The other reason is any changes in reactance around 1:1 SWR are meaningless to system operation. If the reactance becomes meaningful, the SWR cannot possible be 1:1. This is why I am pretty uncomfortable with any claim tuning for minimum reactance magically produces maximum field strength.
Tune for maximum FS is the most accurate.
The SWR detecttors are designed to work at 50 ohms so if the impedance is not 50 ohms they are no longer calibrated and read inaccurately. A matching unit on a conventional antenn matches the 50 ohms so that the bridge reads correctly.
The Db
Why do you so strongly espouse one when choosing from either option will make no noticeable difference? You have stated a fact out of one side of your mouth that you won't notice the difference, while at the same time you are saying that you should use this one and only method, period, end of story out of the other side of your mouth. That is the problem I have with what you are saying, you are trying to have your cake and eat it to. I should mention at this point that I don't personally use either of these points to tune an antenna, if you want to know what I tune for you will have to find it above in one of the previous posts I mentioned it.
I agree. like 543 said if you gonna preach you need to answer.
CTR you mentioned fragmented, the reason being is Your quote about certain rules not be broken.
Fact is Theory is Not always correct or Apply in Real World applications.
Many of the so called experts have never actually played with mobile antennae, much of the published material I found in the 60s was based upon theory not practice.
A short mobile antenna requires 3 things:
Maximum Current into the antenna
Maximum Voltage across the antenna
The correct Phase relationship between the Voltage and Current, this only occurs at Resonance and away from it, the antenna efficiency drops like a stone.
Tony
This is partly why I get a hoot out of reading tuning for low reactance is better than tuning for low SWR. The other reason is any changes in reactance around 1:1 SWR are meaningless to system operation. If the reactance becomes meaningful, the SWR cannot possible be 1:1. This is why I am pretty uncomfortable with any claim tuning for minimum reactance magically produces maximum field strength.
Tune for maximum FS is the most accurate.
The SWR detecttors are designed to work at 50 ohms so if the impedance is not 50 ohms they are no longer calibrated and read inaccurately. A matching unit on a conventional antenn matches the 50 ohms so that the bridge reads correctly.
The Db
Why do you so strongly espouse one when choosing from either option will make no noticeable difference? You have stated a fact out of one side of your mouth that you won't notice the difference, while at the same time you are saying that you should use this one and only method, period, end of story out of the other side of your mouth. That is the problem I have with what you are saying, you are trying to have your cake and eat it to. I should mention at this point that I don't personally use either of these points to tune an antenna, if you want to know what I tune for you will have to find it above in one of the previous posts I mentioned it.
I agree. like 543 said if you gonna preach you need to answer.
CTR you mentioned fragmented, the reason being is Your quote about certain rules not be broken.
Fact is Theory is Not always correct or Apply in Real World applications.
Many of the so called experts have never actually played with mobile antennae, much of the published material I found in the 60s was based upon theory not practice.
A short mobile antenna requires 3 things:
Maximum Current into the antenna
Maximum Voltage across the antenna
The correct Phase relationship between the Voltage and Current, this only occurs at Resonance and away from it, the antenna efficiency drops like a stone.
Tony
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Theory, that is Generally Accepted Antenna Theory, does in fact match reality pretty close to perfectly. Generally Accepted Antenna Theory has been developed and well tested over the years. If the something that comes across as theory doesn't match reality then one of two things happened, either that theory is not part of Generally Accepted Antenna Theory, or if it is you missed something that needs to be accounted for.
Their are many things floating around that are more or less a misunderstanding of what Generally Accepted Antenna Theory states, and erroneously presented by many as fact. We call them Myths. Many of the CB books that date to the 60's you mention have this type of information within. So how do you know one from the other? Research.
Most people here have, and many of the books that I reference (ARRL Antenna Book series which is authored by hams for example) the authors also have. I'm not saying this is the case for all of the books available, but the most commonly purchased books on the subject (ARRL Antenna Books) are written by people who have actual experience with the antenna designs talked about in said books, and often point to real life example antennas including pictures of said antennas. The ARRL Antenna Book series has always been that way, and dates to before the 1960's.
All three of these are really irrelevant as in a mobile antenna, if you get a low SWR (if you don't you won't be using your CB in the first place, at least not very long) these have for the most part already been accounted for.
The lack of efficiency isn't actually caused by the phase mismatch itself, but you should understand this already with what was discussed above...
The DB
I bought a Wilson 1000. I set the SWR on it, got a 1.2:1. I talk on the radio. I get out good. My radio hasn't blown up from the antenna. Must be close. 
It's not rocket science.
~Cheers~
It's not rocket science.
~Cheers~
So an antenna should be ultratuned or performance suffers, but anything over 100 watts is a waste of time and money because the receiving station won't notice?
I bought a Wilson 1000. I set the SWR on it, got a 1.2:1. I talk on the radio. I get out good. My radio hasn't blown up from the antenna. Must be close.
It's not rocket science.
~Cheers~
Wilson 2000, 5'shaft, flat bar mirror mount, 12ft coax (enough to get from point A to B), SWR tuned to 1.2:1, and talking everyday as well!!
If your antenna only radiates half the energy you put into it you just have to double the size of your amp.
40
CTR said: ↑
First of all, using the word "resonance" is pointless. I'm not sure where that came from, but it is a nebulous parameter. By definition resonance is when voltage and current are in phase, or when reactance is zero. So what do you call "resonant"? Do you mean when the imaginary part of the feed point impedance is zero? When the voltage and current are precisely in phase, or do you still call it "resonance" when they are 10 degrees out? How about 20?
This goes along with what many people say about resonance, but it is at best incomplete. I would expect someone who understands what noise temperature is to know this.
Db can you explain why this is incomplete ?
M. Walter Maxwell said:
THIRD, we should become more familiar with the universally known, predictable behavior of off-resonance antenna-terminal impedance and its correlation with SWR. This knowledge provides a scientific basis for evaluating SWR-indicator readings in determining whether the behavior of our system is normal or abnormal, instead of blindly accepting low SWR as good, or rejecting high SWR as bad.
The above i think is why you quoted maxwell as far as CTR being incomplete ?
CTR said: ↑
First of all, using the word "resonance" is pointless. I'm not sure where that came from, but it is a nebulous parameter. By definition resonance is when voltage and current are in phase, or when reactance is zero. So what do you call "resonant"? Do you mean when the imaginary part of the feed point impedance is zero? When the voltage and current are precisely in phase, or do you still call it "resonance" when they are 10 degrees out? How about 20?
This goes along with what many people say about resonance, but it is at best incomplete. I would expect someone who understands what noise temperature is to know this.
Db can you explain why this is incomplete ?
M. Walter Maxwell said:
THIRD, we should become more familiar with the universally known, predictable behavior of off-resonance antenna-terminal impedance and its correlation with SWR. This knowledge provides a scientific basis for evaluating SWR-indicator readings in determining whether the behavior of our system is normal or abnormal, instead of blindly accepting low SWR as good, or rejecting high SWR as bad.
The above i think is why you quoted maxwell as far as CTR being incomplete ?
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Please let this thread die already. If I'm not too concerned with resonance, and ok with a good vswr , you really expect an otr driver to care more? His squelch will be so high it would take 500 watts within a quarter mile to break it anyways. Trust me, I have done it myself. Let it die, let it die, let it shrivel up and die...