5/8wave workman swr issues? Balun? Unun?

[ghutch]

First off Thanks to all the folks that took the time to help and teach!! That what this forum is about....again thanks!
Started over re measured all the parts....installed per the maco instructions....set the antenna up on the beach....this time I set swr with the radials off. Worked down as low as I could get it to go....and be about the same on 1 and 40. Installed the radials and the SWRs went up....now I shortened the radiator a few inches and the SWRs went down to 1.25. That was the best I can get.....added some water at the mast base to get a better ground and they went down more but just slightly
Once I get it to the location we plan o use it the mast will be in wet sand right at the waters edge and I hope it will be lower or at least no higher. 1.25 is workable....the mast used in the testing was only 10 and my truck was only
30 feet or so away. At the site we plan on 20 feet high and will not have any metal objects close. Looks like I have an antenna.
Learned several things reading the thoughts here and DB's other post.....using a coil or matching device we can make an off resonance radiator have a low swr but the pattern and efficiency would be horrible.....same thing as a 102 whip via a tuner would work on 40 Mtrs but not very well.
What I don't get very well is the ideas of resistance ? And reactance ? Anyone?

 

[The DB]

When you mentioned resistance were you by chance referring to impedance? Impedance is basically resistance to an AC signal, like the signal that is transmitted from the back of the radio. Assuming that is what you meant...

Long drawn out description made short.

Impedance matching determines how well power is transferred from the transmission line to the antenna. Your SWR meter is a common device used to measure this.

Resonance determines how well the antenna radiates the power that is transferred to it. Your SWR meter cannot measure this, it requires an antenna analyzer to measure this. (Some other equipment used to be used for this, a noise bridge was it? Was before my time...)

There is a bit more to it than this but this should give you an idea what is happening and where the terms fit in to what is being said. Some antennas these can be tuned independently, others not so much. I tune for resonance when not given an option. Luckily, in most of those cases resonance is usually at a point that is also a good impedance match (1.5:1 or 2:1 SWR on an SWR meter, as that is what you are familiar with to my knowledge.)


The DB

 

[ghutch]

Exactly.....my thoughts are if the impedance (my terms were wrong)match from the radio feedline to the antenna is @ 50 ohms all of the signal is radiated as a signal..10 watts to the antenna and 10 watts radiated out....use of any matching device is going to let less signal radiate....heat the coil? ....thus lower efficiency?
The closer the match the better.....50 ohms matched antennas should, i think first hear better as all the signal is presented to the radio and transmit all of the wattage or a higher percentage with a direct match or very close to direct match.
Any form of match...be it a gamma, hairpin, coils etc. are a point of loss. these matching devices are just a point where we match one impedance to another of different value. As a 50 ohm feed to a 100 ohm antenna?
To produce antenna gain, from the lower angle of radiation a 5/8 wave vertical produces we have a mismatch at the feed point? Thus the need for the match at its base. My question is if the match is off we could see no gain from the 5/8 antenna vs a 1/4 wave? I produced a 1.75 swr on 27.500 with radiator matched at the mid portion of the 10 meter band! By using the coil match it was useable but would be very poor as an antenna system.

 

[The DB]

Exactly.....my thoughts are if the impedance (my terms were wrong)match from the radio feedline to the antenna is @ 50 ohms all of the signal is radiated as a signal..10 watts to the antenna and 10 watts radiated out....use of any matching device is going to let less signal radiate....heat the coil? ....thus lower efficiency?
The closer the match the better.....50 ohms matched antennas should, i think first hear better as all the signal is presented to the radio and transmit all of the wattage or a higher percentage with a direct match or very close to direct match.
Any form of match...be it a gamma, hairpin, coils etc. are a point of loss. these matching devices are just a point where we match one impedance to another of different value. As a 50 ohm feed to a 100 ohm antenna?
To produce antenna gain, from the lower angle of radiation a 5/8 wave vertical produces we have a mismatch at the feed point? Thus the need for the match at its base. My question is if the match is off we could see no gain from the 5/8 antenna vs a 1/4 wave? I produced a 1.75 swr on 27.500 with radiator matched at the mid portion of the 10 meter band! By using the coil match it was useable but would be very poor as an antenna system.

What you are saying about trying to get to a perfect SWR match sound good in theory, but...

To start I will quote the ARRL Handbook 2013, Chapter 20 Page 16, under a section called "20.4.6 Myths about SWR, the last paragraph.

Fortunately or unfortunately , SWR is one of the few antenna and transmission-line parameters easily measured by the average radio amateur. Ease of measurement does not mean that a low SWR should become and end in itself! The hours spent pruning an antenna so that the SWR is reduced from 1.5:1 to down to 1.3:1 could be used in far more rewarding ways -- making contacts for example, or studying transmission-line theory.

The fact of the mater is once you get past a certain point you won't notice the difference gained from lowering SWR's further, and neither will the people on the other end. In some cases it might actually be detrimental, if lowering the SWR reading is actually pushing you away from the resonant point of the antenna.

The power gains you are seeking that are achieved with a perfect match compared to, say, your 1.75:1 SWR are insignificant in the real world. You are past the point that you or anyone else will notice the difference. Conditions you have no control over will affect your signal noticeably more than getting to that perfect match.

I know it is hard to get past the point of wanting that perfect match. Unfortunately to much information posted comes from (or at the very least is directed towards) people who only have an SWR meter. This information covers a small part of what is happening with antennas, but is apparently seen as the whole picture. People take this limited part of what is happening to its logical extreme of insisting on that perfect match.

It's a fine goal, to be sure...

I'm not saying a perfect match is a bad thing, but a goal is all it is. I'm simply stating that you are past the point that any gains in getting to that perfect match will be noticed. I applaud the effort to get to that point just for the sake of getting there, but thinking that it will actually benefit you greatly is a myth.

Interesting that you bring up a 1/4 wave antenna for comparison. There are times that a 1/4 wave antenna will outperform a 5/8 wave antenna. Sounds odd at first as the natural human instinct says longer has to be better, but in the real world you will rarely have more than half of an s-unit difference between the two, and sometimes the 1/4 wave antenna will actually have the stronger reading. The 1/4 wave also has different advantages when it comes to DX'ing.

Have you even tried to use the antenna? With all this discussion about it I have yet to see anything about weather or not you have actually tried to use it...


The DB

 

[northern35s]

A salt water location will provide you with a very very low take of angle and increased gain, it is the best place for your vertical antenna, it's one of the reasons why I can work Western Australia long path with 500mW, it's why a station in Hawaii said I was the strongest signal coming out of Europe when using just 80W, and why another chap in Eastern Australia received me around 30dB stronger on his upper yagi at 250ft compared to his lower yagi at 60ft, and the main reason I spend most of my DXing on foot or mobile

 

[ghutch]

DB .... Yes the antenna has been used. Works very well for the times I tested it. After getting my lowest Swr at the beach setup in the sand dunes....I thought my ground might be bad as the sand was not wet, it was damp but not wet at the mast(steel fence top rail). I poured a bucket of water around the mast bottom to be sure I was getting a proper ground and the swr did take a slight dip down? Next test is going to be at the surf/waterline.
The antenna has less noise then my Wilson 1000' not sure why? but it has less background or hash? Not by any large amount be you can hear a reduction switching from one to the other. Also switching between the two the 5/8 seems to hear the stations at or just above noise level a little better....all dx
I would like to have a local station give me a report on signal level out at a few miles but thus far no one local on the band. I've been reading a site YF1AR about dx antennas for saltwater locations....he has used 1/2 wave verticals at the water line with good results....and has added a reflector to some verticals and used as a beam? His study is for 1/2 wave so I'm not sure if the same principal applies to 5/8 verticals....I have two due to an order error so I may try? I thought about shortening both to half waves and spacing but these are end feed antennas....his study is on 1/2 wave dipole mounted vertical and then added a reflector?
But to answer your question I have used the antenna several times now. It is working ok but on dx I don't think I get a true comparison. Now I have begun to read about getting a close match at the antenna....rather than put as much focus in the swr 1.25 will work....and it will change as I move about.

 

[ghutch]

Northen35s.....cool QRP contacts. I was in a 3 way qso last weekend I was at 20 watts, two stations in s Africa at 12 watts and a station in north Ontario at .790 mw. All four stations had workable signals....not real QRP but a load of fun!
If the TOA is optimized for an area low power should work as well as 100 watts if the band is open? I'm sure 100 watts could give a better contact pushing thru QRM....but just trying to work these type contacts is more of a challenge.

 

[Marconi]

What you are saying about trying to get to a perfect SWR match sound good in theory, but...

To start I will quote the ARRL Handbook 2013, Chapter 20 Page 16, under a section called "20.4.6 Myths about SWR, the last paragraph.

The fact of the mater is once you get past a certain point you won't notice the difference gained from lowering SWR's further, and neither will the people on the other end. In some cases it might actually be detrimental, if lowering the SWR reading is actually pushing you away from the resonant point of the antenna.

The power gains you are seeking that are achieved with a perfect match compared to, say, your 1.75:1 SWR are insignificant in the real world. You are past the point that you or anyone else will notice the difference. Conditions you have no control over will affect your signal noticeably more than getting to that perfect match.

I know it is hard to get past the point of wanting that perfect match. Unfortunately to much information posted comes from (or at the very least is directed towards) people who only have an SWR meter. This information covers a small part of what is happening with antennas, but is apparently seen as the whole picture. People take this limited part of what is happening to its logical extreme of insisting on that perfect match.

I'm not saying a perfect match is a bad thing, but a goal is all it is. I'm simply stating that you are past the point that any gains in getting to that perfect match will be noticed. I applaud the effort to get to that point just for the sake of getting there, but thinking that it will actually benefit you greatly is a myth.

Interesting that you bring up a 1/4 wave antenna for comparison. There are times that a 1/4 wave antenna will outperform a 5/8 wave antenna. Sounds odd at first as the natural human instinct says longer has to be better, but in the real world you will rarely have more than half of an s-unit difference between the two, and sometimes the 1/4 wave antenna will actually have the stronger reading. The 1/4 wave also has different advantages when it comes to DX'ing.

Have you even tried to use the antenna? With all this discussion about it I have yet to see anything about weather or not you have actually tried to use it...

The DB

DB, I am a big supporter of the 1/4 wave radiating element with a suitable ground plane attached at a good height above ground.

And here are two models both at 32' feet showing the patterns, one is a 102" 1/4 wave radiator with 4 x 102" slanted down radials. The other is a standard looking 5/8 wave with 4 x 105" horizontal radials.

The difference in these patterns, if correct, symbolizes the advantage that a 1/4 wave could have over a 5/8 wave under the right conditions. With the 5/8 wave pattern, every angle above 11* degrees, 2 degrees above its maximum angle, will present 50%-100% less RF due to its narrow lobe shape. That is the point I make.

However, there are lots of other factors to consider, but the shape and magnitude of the maximum working surface of these patterns has to be considered as well...when DX is coming in at all kinds of angles with reflected sky waves.

View attachment .25 wave vs. .625 wave patterns.pdf

Just something to consider.

 

[Marconi]

ghutch, I thougt maybe you would interested to see what Eznec suggested about these two models I posted above, if I place the models over what Eznec describes as salt water.

Take note of the differences around 3* and 4* degrees and you will see that the 1/4 at the height of 32' for these models shows almost twice as much RF in the lowest angled lobe.

I don't know how high your antenna is, so these results may differ due to height. I used models I already had at 32' feet.

View attachment ghutch's models over salt water..pdf

 

[The DB]

Personally when it comes to DXing I think the TOA isn't nearly as important as many people think it is. I wasn't really interested in getting into another discussion over this, but will put forth a hypothetical situation.

Say you get all of the radiated signal in the lowest RF lobe at say 5 degrees. This is great for further away contacts, no argument with that. However, if conditions would allow for skip at say 15 or 20 degrees and you are putting little to no signal at that angle you are effectively skipping over potential contacts. This is fine if the person you wish to contact happens to be in the narrower area you wish to talk to, but if they are not, or you are just looking for contacts...


The DB

 

[northern35s]

Personally when it comes to DXing I think the TOA isn't nearly as important as many people think it is. I wasn't really interested in getting into another discussion over this, but will put forth a hypothetical situation.

Say you get all of the radiated signal in the lowest RF lobe at say 5 degrees. This is great for further away contacts, no argument with that. However, if conditions would allow for skip at say 15 or 20 degrees and you are putting little to no signal at that angle you are effectively skipping over potential contacts. This is fine if the person you wish to contact happens to be in the narrower area you wish to talk to, but if they are not, or you are just looking for contacts...


The DB

There's very little I'd call DX that doesn't require a low take off angle, it's also a good reason why one needs to be realistic about what one hopes to achieve with their antenna, a low take off angle benefits long distance contacts, and a higher angle will benefit shorter distances, that's not to say a low take off angle won't work short DX, and vice versa, it's just not as efficient

 

[hookedon6]

...the use of any matching device is going to let less signal radiate....

To produce antenna gain, from the lower angle of radiation a 5/8 wave vertical produces we have a mismatch at the feed point? Thus the need for the match at its base. My question is if the match is off we could see no gain from the 5/8 antenna vs a 1/4 wave?

:blink: actually, in most cases a matching device will allow MORE power to the load, many rigs will fold back the power delivered into a high VSWR.

antenna gain has absolutely nothing to do with VSWR mis-match, the only way to produce antenna gain is to "focus" the radiated power in certain directions and to prevent radiation into other directions.

 

[ghutch]

It is my understanding the 5/8 wave antenna produce some gain vs the 1/4 and 1/2 wave vertical due to a slightly lower angle of radiation...thus some gain at lower angles.
This gain is not my goal...it would produce only a slight increase in local radiation patterns. 1 db or so? My goal is purely dx, I want the lower angle for working dx. My location is at waters edge and reading the YF1AR website verticals at saltwater have a very low angle of radiation.
Has anyone ever looked at using a 5/8 radiator with a reflector to get more gain...a vertical beam? using one vertical radiator and another as a director or reflector? As I look at the sirio gain master it appears to mr to be a 1/2 wave vertical dipole? Is this correct? Looks to be center fed up in the Fiberglas pole...or it may be an OCF dipole....not sure if the feed point is exactly centered. From my reading it may be a better starting point for using as a vertical dipole than the 5/8 maco copy.

 

[Marconi]

It is my understanding the 5/8 wave antenna produce some gain vs the 1/4 and 1/2 wave vertical due to a slightly lower angle of radiation...thus some gain at lower angles.
This gain is not my goal...it would produce only a slight increase in local radiation patterns. 1 db or so? My goal is purely dx, I want the lower angle for working dx. My location is at waters edge and reading the YF1AR website verticals at saltwater have a very low angle of radiation.
Has anyone ever looked at using a 5/8 radiator with a reflector to get more gain...a vertical beam? using one vertical radiator and another as a director or reflector? As I look at the sirio gain master it appears to mr to be a 1/2 wave vertical dipole? Is this correct? Looks to be center fed up in the Fiberglas pole...or it may be an OCF dipole....not sure if the feed point is exactly centered. From my reading it may be a better starting point for using as a vertical dipole than the 5/8 maco copy.

IMO, the GM is a center fed 5/8 wave radiator, and the technical indications shows an improved free space pattern over a standard 5/8 wave ground plane. That is the advertised gain advantage.

Like you suggest, in my operations here in Houston I don't see a real benefit with my GM over my Starduster at almost the same height, locally or with DX. I've been comparing them over a year now, but for me all my antennas perform about the same and guys don't like to hear that.

I thought you were doing your radio work like field day work, and thus out of convenience your install was pretty low. How high is your mount?

If you live right on the water and you want to see some real improvement in DX performance, then install a real beam h o r i z o n t a l.

Aluminum takes a real beating that close to salt water and so would a rotor, but that would be my suggestion. Maybe a quad design with some good copper wire that doesn't stretch much, fiberglass and stainless parts would hold up better, but then you have wind to deal with too.

Good luck,

 

[BOOTY MONSTER]

same tip top height or same feed-point height ?