Capacitance Hat's Don't add Audio

[Shockwave]

Are you suggesting the full 90° whip is not a 1/4ƛ whip? I am asking, not debating.

No Homer, I definitely agree that an antenna 90 degrees is equal to a 1/4 wave. Also the current on the Yagi element is maximum at it's feed point. It's the voltage that is at minimum here. The same condition occurs at the feed point of the end fed 1/4 wave.

 

[HomerBB]

Coily,
I am completely neutral on this debate. I have no beef with you. I've always taken the view on most anything that a person's experience is never the servant to another's argument.

In fact, I heard the story of a fellow who, when walking by the fields of a farmer proceeded to tell the farmer of everything that was wrong with his fields. The rows went contrary to drainage, they were crooked, not tilled deeply enough, and generally everything the books told him was out of kilter.
The farmer asked the stranger where his farm was located, to which the critic answered, "I don't have a farm"
Well then, the farmer says, neither do you have an argument.

That said, in one non-scientific test of several antennas I had put together i found at least one that had a reported, and observed superior performance to the none loaded whip I tested in the group. I did not take it as a final report on all performance parameters for those antennas, but it did show me that from/to the same two stations, my mobile, and a 10 mile distant base, there was a circumstance in which the loaded antenna out performed the whip. Of 6 antennas tested only one of the loaded out did the whip, but all of them showed to be doing as well and nearly as well.

I'm not trying to educate you. I'm trying to educate me. I am just trying to learn while looking at data that seems to say more then is apparent in the thread by casual reading.

I've no beef with you, nor anyone. and I have no doubt your antennas prevailed in the shootouts. I'm trying to learn why for each case of differing antenna performances.

Respectfully,
Homer

 

[Shockwave]

like i said looks great on paper real nice graph and everything when you add all your numbers...but the coil still beats it been proven a million times.also if you move your h1 and h2 you will see better gains.steel whips make good stinger.you guys need to build a couple thousand antennas then you will see what works..the books are a good start computer programs help but that dont touch real world hands on.dont have tp try to school me i have what i need thanks..have great day..live well play hard and dont forget to get out and do it not preach it.all my antennas work as claimed.

It's comments like this that imply the books were written before the experts experimented with thousands of antenna designs. Stop assuming the carriage has been put in front of the horse on this one.

 

[HomerBB]

No Homer, I definitely agree that an antenna 90 degrees is equal to a 1/4 wave. Also the current on the center fed Yagi element is at maximum in the center. It's the voltage that is at minimum here. The same condition occurs at the feedpoint of the end fed 1/4 wave.

Thanks again. I told you I'm trying to sort this out.

SO the voltage is greatest at the end of the Yagi/dipole elements, and the ARRL Handbook say the properly made coil forces more current into the upper 15° of the loaded antenna because of the high voltage that occurs at the top of the coil. I read this as an apparent change from the normal occurrence in the non-loaded 1/4 wave whip.

Why does the ARRL book seem to disagree that the voltage is maximum at the ends of the 1/4 wave? Or if it doesn't, why is the ARRL Handbook saying that a coil increases the voltage, as in steps it up to higher voltages, and this not improve performance?

 

[Shockwave]

Okay, but could we not then make an additional case for when the loaded antenna might outperform a whip in the same location?
For instance on a tall SUV the whip likely would out perform a well designed loaded antenna, but on a low riding sedan the loaded antenna would put more radiation at the upper 15° of the antenna, an area where the longer whip is less effective, giving the loaded antenna the advantage. In the graphic the shaded area clearly shows advantage in radiation strength for the loaded antenna well along its upper length.
I know most are saying the whip in any case outperforms the loaded antenna, but unless the radiation strength of an antenna means something other than what affects output/field strength I have much more to learn than what I was thinking.

If this idea really worked we would also see AM radio stations adding a second insulator on the tower so they could load the top half of the radiator. No antenna has it base lower to the ground then the standard broadcast Marconi. It makes more sense to me that the effect has more to do with direct blockage from the vehicle body then actual antenna height above ground.

 

[Shockwave]

Thanks again. I told you I'm trying to sort this out.

SO the voltage is greatest at the end of the Yagi/dipole elements, and the ARRL Handbook say the properly made coil forces more current into the upper 15° of the loaded antenna because of the high voltage that occurs at the top of the coil. I read this as an apparent change from the normal occurrence in the non-loaded 1/4 wave whip.

Why does the ARRL book seem to disagree that the voltage is maximum at the ends of the 1/4 wave? Or if it doesn't, why is the ARRL Handbook saying that a coil increases the voltage, as in steps it up to higher voltages, and this not improve performance?

Homer, can you provide the exact quote from the handbook that is leading you to believe that voltage is not highest at the end of the 1/4 wave or at the two ends of the dipole? If it says something like this, we need to report the error to the ARRL. Google search current / voltage distribution on either the 1/4 wave or dipole and it will return many images that confirm this.

 

[WR0220]

Two things can be done to improve this distribution and make the current more uniform. One would be to increase the capacitance of the top of the antenna to ground through the use of top loading or a capacitance hat, . . . The other method is to place the loading coil farther up the whip, as shown in Fig 7, rather than at the base. If the coil is resonant (or nearly so) with the capacitance to ground of the section above the coil, the current distribution is improved as also shown in Fig 7.
The result with both top loading and center loading is that the radiation resistance is increased, offsetting the effect of losses and making matching easier."

ARRL Antenna Handbook ch.16

I think a key point was overlooked in the quoted material (see underlined above). The ease of matching an antenna is only a portion of what's necessary for it to perform efficiently. A dummy load will provide an excellent match, but is a terrible radiator. Resonance and TOA play a major role in performance. From everything I have read, studied and applied this is where the 1/4 wave has an advantage over any type of antenna that utilizes a coil to reduce overall physical length. I have no doubt that field strength may be strong at close range with a coiled antenna, but far field - and how my signal arrives at the horizon - is more important to me.

 

[HomerBB]

Homer, can you provide the exact quote from the handbook that is leading you to believe that voltage is not highest at the end of the 1/4 wave or at the two ends of the dipole? If it says something like this, we need to report the error to the ARRL. Google search current / voltage distribution on either the 1/4 wave or dipole and it will return many images that confirm this.

No. Thanks again. Once again had a brain fart. It says it has high voltage at the top of the coil which increase current at the upper end of the antenna which increases radiation in the upper 15° of the antenna which supports the idea that a coil improves the performance of the upper 15° of the loaded antenna over the upper 15° of a full 90° whip.

I accepted your reply regarding voltages and current on the dipole. I meant to ask whether the increased current that the coil adds does or does not lead to superior performance potential for the loaded antenna in circumstances where it is mounted on a lower vehicle. ARRL handbook does say it increases radiation, which I read as improves performance.

I wish I had reread more carefully what I was writing. I am trying to learn this stuff more completely.

It does make me wonder about whether or not there are high voltages at that point on the antenna where the coil is if the coil weren't there.

 

[HomerBB]

I think a key point was overlooked in the quoted material (see underlined above). The ease of matching an antenna is only a portion of what's necessary for it to perform efficiently. A dummy load will provide an excellent match, but is a terrible radiator. Resonance and TOA play a major role in performance. From everything I have read, studied and applied this is where the 1/4 wave has an advantage over any type of antenna that utilizes a coil to reduce overall physical length. I have no doubt that field strength may be strong at close range with a coiled antenna, but far field - and how my signal arrives at the horizon - is more important to me.

I had hoped someone would cite that piece of the quote and reply to it. I left it in because of the honesty of my inquiry, but I wanted someone to speak to it without me feeding them that dimension of the discourse. I am also persuaded that there is more to the antenna than meets the eye, and like a diamond, it has to be viewed for hte full effect of all it facets.

That is why my mobile antenna tests of my home mades will not be complete until I can test them over a longer distance than the 10 miles i used. It is too limited a test to tell the whole story of those antennas with different sized, placed, height, etc loaded coils.

 

[MrSuburban]

MrCoily, apparently you do not see the opportunities that having a patent would provide you with.

you have the ONLY capacitance hat in the known universe that increases performance!!!

James Maxwell would be flipping out if he were still alive!

why would anyone with this kind of original knowledge be wallowing in the lowly CB antenna market???

could it be that you are a true philanthropist and just want to give back to the CB community?

could it be that you cant fully explain all the technical aspects of your performance enhancing capacity hat, and therefore are having trouble finding a patent lawyer?

or could it be that the CB antenna market is fraught with unsuspecting potential customers who dont understand how these things work, but are willing to spend a buck on a potential advantage?

all it takes is someone to make some lofty claims and then back it up with so-called "real world tests". i mean, if there are 10,000 people that are going to buy an antenna this year, and only 10% of them actually believe this hype; well you've still sold 1000 antennas.
its just a numbers game i guess...

then all you have to do is spend some time doing "damage control" on the internet forums by adopting a "tolerant genius" sort of attitude whereby you seem so smart that you dont ever have to actually explain anything, you just laugh at the puny mortals that dare question your laws.

seems like you already know all of this which means that you know that there will always be people gullible enough to try the latest gizmo, and that you are poised perfectly to make a buck off of them.

good job sir, you are a true asset to the CB community. :thumbdown:
LC

This has to be one of the best posts ever on WorldWide DX forum.

 

[BOOTY MONSTER]

how much is the radiation increased in the upper %15 of the antenna ? more is more , but how much more ? from my own experience increasing power %100 or decreasing %50 didnt seem to effect my contact success . if %100 more signal/power (?) on a full length 1/4 wave vertical (speaker wire and pvc) didn't have much effect , how much more radiation does the upper %15 of the coil loaded antenna to achieve a detectable signal difference ?

 

[HomerBB]

If this idea really worked we would also see AM radio stations adding a second insulator on the tower so they could load the top half of the radiator. No antenna has it base lower to the ground then the standard broadcast Marconi. It makes more sense to me that the effect has more to do with direct blockage from the vehicle body then actual antenna height above ground.

Makes sense.
I have read where it was said that some of the work of a GP at the base of a vertical antenna was there to decouple the antenna from the earth while doing other things like improving the TOA and decoupling the feedline to improve CMC issues.

If the GP reintroduces the earth . . . never mind. The vehicle is part of the mobile antenna system, but the real GP is the earth over which the automobile sits. Not the same. The vehicle does not replace the earth . . . yes/no?

Now I may have a new blank to fill in . . .

Can you tell me why the AM stations set up as you've said/asked?
Would this suggest that capacitance higher on the antenna could reduce signal on the horizon where the commercial radio station must put its signal to service it customers/listeners effectively? Or is it something else?

And could this apply to mobiles?

 

[MrSuburban]

This article is comparing loaded antennas to other loaded antennas. It does not compare the loaded antenna to the unloaded. The first paragraph seems to refer to a base loaded 1/4 wave since the second paragraph suggests it's performance can be improved by moving the coil higher or adding a capacitance hat. Neither one of these actions can increase the performance of the unloaded 1/4 wave or make the loaded antenna equal to or greater then the unloaded antenna.

Bingo, and this is what happens when guys who don't understand what they are reading and what it pertain's to they try to craft it to there situation or think it is an answer to what they are doing.

 

[HomerBB]

how much is the radiation increased in the upper %15 of the antenna ? more is more , but how much more ? from my own experience increasing power %100 or decreasing %50 didnt seem to effect my contact success . if %100 more signal/power (?) on a full length 1/4 wave vertical (speaker wire and pvc) didn't have much effect , how much more radiation does the upper %15 of the coil loaded antenna to achieve a detectable signal difference ?

A good question, but I haven't found the answer yet in the ARRL Handbook. I'm just trying to get some understanding from the forum for the questions reading the handbook has raised for me.

Maybe it's about improving TOA, more of the entire signal to horizon.

May not help much in these hills, but I would think it might out on the prairie.
And I'm not sure it's a discussion of wattage out. Someone may help us here.

 

[mrcoily]

i love you guys...if it was not for you guys and your massively thick books how would i ever get along HOw ould we all get along with out you supreme being of knowledge...lol....oh dear oh my i think i may have to run and hide.I would like to thank all you for the kind words and i would like to ask that you please keep it up..my hit counter just quivered.