End Fed 1/2 wave antenna

[HomerBB]

I have the antenna in the air using it right now, When conditions are in I do just fine with it DX wise, and local seems to work although there isn't much local going on.
Like you, I have a set of PC speakers in the shack that love to report RF issues. I am currently getting no such squawk from them whether running a little power or not.

 

[Marconi]

I have the antenna in the air using it right now, When conditions are in I do just fine with it DX wise, and local seems to work although there isn't much local going on.
Like you, I have a set of PC speakers in the shack that love to report RF issues. I am currently getting no such squawk from them whether running a little power or not.

Can't beat that.

 

[nav2010]

Eddie, you seem to have an idealogy that because GP kits do not and havn't worked for you then they cannot possibly work for anyone or in any other case scenario. I've had results with GP kits on half wave end feds, .64 homebrew and an Antron 99 which I am currently using. I have the mast isolated from the antenna, I do this so that the electrical length of the ground planes cannot be affected by the mast and detune them, I also have a choke on the feed point so as to force CMC's into those very radials and operate at what ever electrical length I want them to, it this case they are 3 quarter wave radials.
Fact - My A99 is no longer a static monster, I no longer or very seldom get static build up which interferes with RX/TX.
Fact - There are 20 breakers in this region ranging from 1 mile to 25 miles and my antenna is on a par with most of them as far as performance is concerned.
Fact - My A99 is equal to a Sirio 827 for breakers 25 miles or more away and I've had an 827
Fact - I DX'd into the United States from the UK on my A99 on 5 watts PEP and 10 watts on a whistle when some local breakers couldn't even break the skin using 100 watts PEP on their antenna's.
Fact - unless you isolate it from the mast and choke your antenna you will NOT force current into those radials and be able to utilize their electrical length to their full potential.
Fact - Strapping a 20 foot mast onto the electrical length of any tuned circuit is an act of madness, ....you wouldn't do it with your driven element so don't do it with your radials.
Crack on old lad.

 

[nav2010]

I would also like to add this:- All unbalanced antenna's no matter what they are will try to form a balancing act with what ever they can get their hands on to do the job. Sometimes they will use the ground, sometimes they will use the mast, sometimes they will use the feedline and sometimes they will use a combination of the three. If we allow an unbalanced antenna to makes its own choice of what it needs to perform this balancing act it may not always benefit us as the operator to allow it to do so. This is why we cut coax into electrical half waves etc. In the case of the end fed vertical antenna we balance the antenna with a tuning coil in as far as the impedance is concerned but that isn't always a perfect way of determining the current and voltage maxima of such an arrangement. Very lossy, leaky and undetermined to a certain degree and the antenna will naturally try to find voltage and current balances in other conductive materials i.e the feedline. The trouble with that is that the antenna can actually detune itself in doing so aswell as causing trouble at the operating end with unwanted currents. All we are doing by Isolating the mast and choking it is to try and force those currents into a beneficial determined electrical property of the antenna as much as we can rather than allowing the antenna to detune itself on undetermined mast and feedline lengths etc. Maxwell tells us that all antenna's try to become a dipole and therefore become balanced, end feds do not have a proportional balance for this to happen and they will find anything they can to correct the balance, its up to you as the operator to intercept that search the antenna is performing and try to persuade it to take the alternative route you have provided.

 

[Marconi]

Eddie, you seem to have an ideology that because GP kits do not and haven't worked for you then they cannot possibly work for anyone or in any other case scenario. I've had results with GP kits on half wave end feds, .64 homebrew and an Antron 99 which I am currently using. I have the mast isolated from the antenna, I do this so that the electrical length of the ground planes cannot be affected by the mast and detune them, I also have a choke on the feed point so as to force CMC's into those very radials and operate at what ever electrical length I want them to, it this case they are 3 quarter wave radials.
Fact - My A99 is no longer a static monster, I no longer or very seldom get static build up which interferes with RX/TX.
Fact - There are 20 breakers in this region ranging from 1 mile to 25 miles and my antenna is on a par with most of them as far as performance is concerned.
Fact - My A99 is equal to a Sirio 827 for breakers 25 miles or more away and I've had an 827
Fact - I DX'd into the United States from the UK on my A99 on 5 watts PEP and 10 watts on a whistle when some local breakers couldn't even break the skin using 100 watts PEP on their antenna's.
Fact - unless you isolate it from the mast and choke your antenna you will NOT force current into those radials and be able to utilize their electrical length to their full potential.
Fact - Strapping a 20 foot mast onto the electrical length of any tuned circuit is an act of madness, ....you wouldn't do it with your driven element so don't do it with your radials.
Crack on old lad.

Nav2010, I remember something about you that is either good or bad, but I just can't remember which. However, your remarks are great.

With out some feed back on what I say sometimes, I know I get all wrapped up in my ideas, which make total sense to me, but the others who might read the words are at a total loss in understanding. If I don't get constructive responses, then I loose, and I don't know when I've messed up.

I will try to address some of you facts, which right off I hope I'm never so categorically in my claims about antennas...as to suggest what I say or do is the gospel truth.

Fact - My A99 is no longer a static monster, I no longer or very seldom get static build up which interferes with RX/TX.

That is a very subjective comment, but I believe you. I see it sometimes and I blame my antenna, then when the static goes away, as it generally does, I wonder if it was something I did, or something that nature did. IMO, if static gets on your antenna, then isolating the mast and effectively chocking the feed line should help eliminate an easy way for the noise to reach your receiver, and that could be better.

The other day I read a post on Charlie Tango, and a guy was telling a story about the reason he replaced his new Gain Master with his old Imax. The story goes, that the GM went deaf at 17 meters, so I checked it out. At 27 mhz, my GM sounded terrible with static, but when I dialed down to to 18 mhz, she got a quiet as a church mouse. I found some code working and I was switching back and forth on the GM and my Starduster. The GM showed no signal, but the audio was 100% readable. I flipped to the SD, which is generally a little quieter than my GM, and the signal was S5, with noise that sometimes blew my read of the code. So, which was best, when actually working the radio and not just looking at the signal, which transmits very little information working our two way radios.

So, this idea is too objective for me, but I believe you.

Fact - There are 20 breakers in this region ranging from 1 mile to 25 miles and my antenna is on a par with most of them as far as performance is concerned.
Fact - My A99 is equal to a Sirio 827 for breakers 25 miles or more away and I've had an 827

My A99 has always worked well for me, and it's the antenna I stack up against all the others, testing to see how much, if any, difference I can see in signal.

Fact - I DX'd into the United States from the UK on my A99 on 5 watts PEP and 10 watts on a whistle when some local breakers couldn't even break the skin using 100 watts PEP on their antenna's.

I haven't worked my A99 with DX for some years now, but I recall when I did, it seemed to work just about as good as any other antenna I had. I don't tend to depend on DX reports for my antenna comparisons work however.

Fact - unless you isolate it from the mast and choke your antenna you will NOT force current into those radials and be able to utilize their electrical length to their full potential.

If you've read some recent posts that I've made, I've talked about my experience modeling and showing that isolation of the mast and the use of radials did decouple the mast from the antenna effectively, but my results along with Homer's recent 1/2 wave results, both showed the difference in gain, angle, and match was hardly noticeable. So again, if we do something we expect positive results, and we didn't see any in real world results showing the match changed. I have never seen any difference in real world testing and my modeling either. So, I've just had different results than you, and now Homer has basically confirmed what I saw. That doesn't mean that I'm trying to say my was is the only way. Your results are evidence of that. I try to show evidence for what I see and why I make the claims I do. I seldom see any evidence from others for what they see, so among us has an ideology issue?

Fact - Strapping a 20 foot mast onto the electrical length of any tuned circuit is an act of madness, ....you wouldn't do it with your driven element so don't do it with your radials.

The final fact. I agree to a point, and I'm not one to argue circuits, but if we attach something in the right spot to a driven element sometimes, we tend to mitigate problems like you suggest. Sometimes it works, and I guess other times, not so much. It is always testy when we try to tap at a voltage node however, so you are right on that count.

On-the-other-hand, the argument has gone on almost as far back as Maxwell and OHM, which suggest that end feeding a 1/2 wave radiator is impossible. But, I don't think the argument holds water, considering bar-non, the most widely used CB antenna in the world is and end fed A99.

Like I say when guy's try to tell me, this or that will make a difference, I ask, "...how much difference does it make?"

I sometimes add, "...is it a difference we can tell just working our radios?

Thanks.

 

[Marconi]

I would also like to add this:- All unbalanced antenna's no matter what they are will try to form a balancing act with what ever they can get their hands on to do the job. Sometimes they will use the ground, sometimes they will use the mast, sometimes they will use the feedline and sometimes they will use a combination of the three. If we allow an unbalanced antenna to makes its own choice of what it needs to perform this balancing act it may not always benefit us as the operator to allow it to do so. This is why we cut coax into electrical half waves etc. In the case of the end fed vertical antenna we balance the antenna with a tuning coil in as far as the impedance is concerned but that isn't always a perfect way of determining the current and voltage maxima of such an arrangement. Very lossy, leaky and undetermined to a certain degree and the antenna will naturally try to find voltage and current balances in other conductive materials i.e the feedline. The trouble with that is that the antenna can actually detune itself in doing so aswell as causing trouble at the operating end with unwanted currents. All we are doing by Isolating the mast and choking it is to try and force those currents into a beneficial determined electrical property of the antenna as much as we can rather than allowing the antenna to detune itself on undetermined mast and feedline lengths etc. Maxwell tells us that all antenna's try to become a dipole and therefore become balanced, end feds do not have a proportional balance for this to happen and they will find anything they can to correct the balance, its up to you as the operator to intercept that search the antenna is performing and try to persuade it to take the alternative route you have provided.

Nav, I read your signature comment, but what if you are wrong? I'm not saying you're wrong, but just supposing.

Have you even bothered to read Yates article on end fed 1/2 waves? All I ask is for you to consider another point of view for a few minutes. I use to think just like you here. AA5TB - The End Fed Half Wave Antenna

I can't be sure, but I think maybe Homer has just completed some testing on his new end fed 1/2 wave using his 259B to test the match with several iterations in construction of the antenna, and he found just about what I've been preaching for a long time, no difference.

Now I know that effort, nor mine, was testing performance, but if we denied the end fed antenna its need for a counterpoise, don't you think removing that vital part...would result in matching differences, and maybe even corrupt the match all together?

Just something else to consider!

 

[nav2010]

Firstly, the A99 is a static monster and so is the Imax, any amount of moving air (and especially in damp conditions) will cause a build up of static somewhere on the antenna and because the glass fibre section can never be DC grounded causes problems. Some people have reported up to S9 of interference in poor weather and i've experienced regular S7 and S8 myself. My guess is that it builds up in the glass fibre sections in pockets just like rubbing a baloon against your head. A few thousand volts of HT on your antenna is what causes the problem. Why doesn't it effect my antenna? - there is in my opinion something stopping the static build up in my electrical field of the antenna.

I don't tend to depend on DX reports for my antenna comparisons work however.

I'm not gonna answer that, its contemptable.

If you've read some recent posts that I've made, I've talked about my experience modeling and showing that isolation of the mast and the use of radials did decouple the mast from the antenna effectively, but my results along with Homer's recent 1/2 wave results, both showed the difference in gain, angle, and match was hardly noticeable. So again, if we do something we expect positive results, and we didn't see any in real world results showing the match changed. I have never seen any difference in real world testing and my modeling either. So, I've just had different results than you, and now Homer has basically confirmed what I saw. That doesn't mean that I'm trying to say my was is the only way. Your results are evidence of that. I try to show evidence for what I see and why I make the claims I do. I seldom see any evidence from others for what they see, so among us has an ideology issue?

Eddie, you've become so apposed to radials working on a Antron 99 that if a set a results came in to your possession proving without doubt they worked you'd sit there watching them burn on your fire with more pleasure than Al Capone would watching his tax returns burn.

The final fact. I agree to a point, and I'm not one to argue circuits, but if we attach something in the right spot to a driven element sometimes, we tend to mitigate problems like you suggest. Sometimes it works, and I guess other times, not so much. It is always testy when we try to tap at a voltage node however, so you are right on that count.

Yes but when we attach something to any driven element we compensate the electrical length by doing so, if we add a anti static ball we always include that ball in its length unless we shunt out the shortfall or the extra length in the matching transformer.
Lots of people think that matching transformers are the answer to all our dreams because they allow us to operate in otherwise impossible conditions, a lot of people think that their antenna ends at such a transformer, far from it - its where it all begins. Its where the balance of nature is met by the incompetance of men.

 

[Marconi]

Now I remember what the issue was that was either good or bad in my recollections about the name Nav2012, it was we'll never agree on anything.

I might burn such a report, but before I did, I would at least read it and try and understand what was presented even if it was different point of view, SO.......

Like many others have shown over time Nav2012, all you have are words. But, if you've got something that shows you done some work to support those words, then come on with it.

 

[HomerBB]

I am going to be away from the house at my in-laws in about 3 week for a week and will need a portable antenna. I have a dipole for that purpose, but decided to throw together a portable end fed wire, too.

The wire element is wrapped around the plastic plate for travel/storage.

 

[Needle Bender]

I love it when people prefer A99s, it gives me & my Penetrator/Gainmaster a 2-3 s-unit advantage.

 

[Needle Bender]

I am going to be away from the house at my in-laws in about 3 week for a week and will need a portable antenna. I have a dipole for that purpose, but decided to throw together a portable end fed wire, too.

The wire element is wrapped around the plastic plate for travel/storage.

...NOW THOSE YOU SHOULD MARKET ON EPAY!

 

[Marconi]

I love it when people prefer A99s, it gives me & my Penetrator/Gainmaster a 2-3 s-unit advantage.

NB, here is my recap of several months combined and averaged signal reports back in the spring of 2011. This shows the ranking of all signals during that whole period for the antennas tested.

This is <gotproof> that I just don't see the differences that most others do. I can't tell you that my numbers are right and that you and the others are wrong, but this is what I observed in doing a lot of work.

My A99 did end up on the bottom, but while I was testing one signal at a time over this 5 month period, I never noticed the difference or 2-3 sunits between any signals, none, nada. Else I would have been shouting hallelujah!

This has always been the case here at my location. Does anyone think this small difference will ever cause me to loose or miss a local type contact? I don't think so. <gotproof>

 

[HomerBB]

If interested, how to make the coil in the above photo.
Materials:
wire
wax paper
blue swimming pool flex hose
Hot glue.

1. Cut a section of this hose, cut it into strips.
2. Wax paper rolled and taped onto cylinder such as PVC pipe.
3. Hot glue strips of hose onto wax paper.
4. Wrap wire for coil around the form into the grooves.
5. Hot glue across all the blue hose strips.
6. Slide wax paper off of the PVC form, remove wax paper from within the coil.

 

[Marconi]

If interested, how to make the coil in the above photo.
Materials:
wire
wax paper
blue swimming pool flex hose
Hot glue.

1. Cut a section of this hose, cut it into strips.
2. Wax paper rolled and taped onto cylinder such as PVC pipe.
3. Hot glue strips of hose onto wax paper.
4. Wrap wire for coil around the form into the grooves.
5. Hot glue across all the blue hose strips.
6. Slide wax paper off of the PVC form, remove wax paper from within the coil.

That is very neat Homer. Is this the design that you used to tune your 1/2 wave? Does it look bigger that it really is?

 

[HomerBB]

No. The wire portable uses this. The one used throughout the thread was different than this one. However, the half wave does currently use a cap and coil just like this one. I haven't reported anything with it. I can use a housing box much smaller with this design.