I-10K/Sockwave model first run

[Marconi]

If I make a big loop Vector model, I can get more gain out of the antenna than the stock dimensions, but it takes more than just making the loop bigger. You have to balance the antennas overall length, and the radial length as well. If your not willing to adjust all three you won't get anywhere.

I think I will try and get my old computer to working as an Eznec machine and then retrieve all my models. If I'm lucky, I will try and confirm your prediction.

I'll be 78 tomorrow, and I don't have time to mess around with personal issues, so I'll check it out and try and answer that question...even if it is for my eyes only.

All this being said, I didn't create this thread to discuss the Vector again. It is a dead subject, and should stay there. Even if I find certain aspects of that antenna interesting, which I do, I have resolved to study them on my own simply because some people treat even questions about various aspects of that antenna as a threat to what they intend to believe with religious like zeal.

DB, no subject is dead until folks stop talking about it.

I have yet to see any Vector model include a gamma matching system, much less a fully tuned version in a model. Hell, I haven't seen many models of other antennas that have been matched and/or tuned either.

Yea, and I might be the only one you'll ever see try and do it too.

The only open discussions I intend to ever have about this antenna is after I make a model that includes tuning with what is as close as I can get to the Vector's matching system and possibly how it compares to other models with their tuning systems modeled and matched as well. I have yet to see any Vector model include a gamma matching system, much less a fully tuned version in a model. Hell, I haven't seen many models of other antennas that have been matched and/or tuned either.

I'm sorry I posted the link.

You're right again, this is why "you are the man."
Folks come and seek your input DB.​

 

[222DBFL]

And I am sorry I asked about the antenna. Didn't realize it would cause such a big deal. Won't do that again that is for sure!! I appreciate you posting the link even if others don't!! And I will leave it at that. To all have a good one.

 

[Marconi]

I redid my I-10K model on my new PC. I checked the dimensions against the Manual and I find the radiator length is possibly an inch or so short, but I didn't mess with it.

DB as noted above, I posted my model may be a little short of specs and I've analyzed our models below, and the model results are very similar. I used a 100 watts of power for the model and our maximum gain currents at the center of the top 1/2 wave portion of the radiator are almost identical at near 1.30 (A), assuming that I also changed my Ground description to "Poor or Very Poor," like you note. My model does not however show the insignificant skewing you mentioned, and my idea of a Trombome matcher added to an end fed, mismatched 5/8 wave vertical monopole is skewed to one side just like you...but it does work to tune.

I wish I could get my model nearer a perfect match like you did...and I would feel little better.



Maybe if I extended my radiator a few inches I would get a better match and Bandwidth result, and our gain figures might be identical.

DB, I think our results tend to indicate just how sensitive and accurate to specs this antenna software can be. Even though real world testing is always recommended to be sure...I think we did pretty good on this project.

BTW, how high did you set your model?

 

[The DB]

And I am sorry I asked about the antenna. Didn't realize it would cause such a big deal. Won't do that again that is for sure!! I appreciate you posting the link even if others don't!! And I will leave it at that. To all have a good one.

You didn't do anything bad intentionally. Discussions on that antenna spawns emotions like not other. I guess it is part of the nature of the beast...

DB, I think our results tend to indicate just how sensitive and accurate to specs this antenna software can be. Even though real world testing is always recommended to be sure...I think we did pretty good on this project.

I would agree. Even if few people use it this way, the fact the modeling software can be used to this effect says quite a bit about the capabilities of software itself.

BTW, how high did you set your model?

11 meters to the radials.

Why don't I just post screen shots of the wire data...

I started with the s variable from the second screen shot above being the same as a single segment length. I also modified that variable, as well as 4NEC2's auto segmentation to get AGT close to 1.

All numbers are in meters.

My vertical element tip was also decided by taking 11 and multiplying it by .625. I didn't know the actual length of the antenna's in question. This model was intended to see if I could build that type of antenna from scratch in modeling software, and I could.

I have a second model, or more accurately a first attempt that I couldn't get to match properly until after I made this one. One of its trombone section wires at the same height and connected directly to the radials where the model I used above has the trombone section completely above the radials. That one shows noticeably more skewing than the model I presented here, and slightly less gain, as well as a slightly lower efficiency. The currents in the radials are even further off of the currents shown in the model I presented here.


The DB

 

[Marconi]

I set the Ground description to Poor and generated the Poor Earth version, and here is a screen shot of the patterns overlaid.


I was thinking about changing the radiator length by 2", the error I noticed earlier and did see an increase in gain, but I'm not sure right now if I did that for this new model over Poor Earth I posted here. However, I did raise the radiator and as I expected the gain for the model did get closer to your results, but still short of your 4.72.

DB, am I correct with my antenna at 32' feet is your model much higher? I did not consider that.

Here is my wires data:

 

[Marconi]

I added 2" to the radiator and changed the Ground description to very poor, but I'm still a little shy of your gain at 4.72 dbi.

 

[The DB]

DB, am I correct with my antenna at 32' feet is your model much higher? I did not consider that.

It is at 11 meters in height. If I convert from meters to feet, I get 36.0892 feet.

Also, as I mentioned above, I haven't yet included a wire to ground, removing that might help you some as well.


The DB

 

[Marconi]

Well if you didn't have the antenna grounded then that will also make some difference. Did you include a mast?

 

[The DB]

Well if you didn't have the antenna grounded then that will also make some difference. Did you include a mast?

Nope, not yet. It is on my list of things to do...

Here is my wires data:

When I put this data into 4NEC2 I get a run segment check message and when I run a segment check I get this text as a result..

eddie.nec wavelength=11.02 mtr.

Warn.: Wire 8, seg 110 (tag 8), EX-src: Nearby segm-length or radius differs too much.
Warn.: Wire 1, seg 1 (tag 1), len/rad at junction (4.013) below 6.
Warn.: Wire 1, seg 85 (tag 1), len/rad at junction (4.013) below 6.
Warn.: Wire 2 (tag 2), seg-len (2.4) below 2 * radius (4)
Error: Wire 2, seg 86 (tag 2), len/rad at junction (1.2) below 2.
Error: Wire 2, seg 90 (tag 2), len/rad at junction (1.2) below 2.
Warn.: Wire 8, seg 110 (tag 8), len/rad at junction (5.331) below 6.
Warn.: Wire 8, seg 110 (tag 8), len/rad at junction (5.331) below 6.
Warn.: Wire 9, seg 111 (tag 9), len/rad at junction (5.774) below 6.
Warn.: Wire 9, seg 113 (tag 9), len/rad at junction (5.774) below 6.
Warn.: Wire 22, seg 391, len/rad at junction (2.405) below 6.

I also still get skewing, but the pattern does come close to matching yours.

Also, 4NEC2 shows an AGT of 1.251 with this as well, which is no where near desirable.

Assuming you didn't have any of these problems in EZNEC, I wonder if there are differences in how both programs treat the same data?


The DB

 

[The DB]

A thought I had and something I just noticed.

I noticed that in my models above the pattern is being shown along the X axis. If I show the pattern along the Y axis for both of them, their is no skewing. This is with both with your model and mine. I could be wrong, but do you know if EZNEC defaults to showing gain along the Y axis? I think 4NEC2 shows the direction with the most gain by default. I do know some models it doesn't default to the X axis...

Something else I noticed between our models. Your trombone section is in line with one set of radials, while mine is not. Looking at pictures of the antennas online, I think the I-10K design is more like your model layout, while the Shockwave appears to be more like mine.

Also, the Shockwave antenna has its radials directly in line with the mast, they are not offset any, again more like my model than yours.

I wonder if these two differences are part of the difference in our models...


The DB

 

[Marconi]

Nope, not yet. It is on my list of things to do...

When I put this data into 4NEC2 I get a run segment check message and when I run a segment check I get this text as a result..

eddie.nec wavelength=11.02 mtr.

Warn.: Wire 8, seg 110 (tag 8), EX-src: Nearby segm-length or radius differs too much.
Warn.: Wire 1, seg 1 (tag 1), len/rad at junction (4.013) below 6.
Warn.: Wire 1, seg 85 (tag 1), len/rad at junction (4.013) below 6.
Warn.: Wire 2 (tag 2), seg-len (2.4) below 2 * radius (4)
Error: Wire 2, seg 86 (tag 2), len/rad at junction (1.2) below 2.
Error: Wire 2, seg 90 (tag 2), len/rad at junction (1.2) below 2.
Warn.: Wire 8, seg 110 (tag 8), len/rad at junction (5.331) below 6.
Warn.: Wire 8, seg 110 (tag 8), len/rad at junction (5.331) below 6.
Warn.: Wire 9, seg 111 (tag 9), len/rad at junction (5.774) below 6.
Warn.: Wire 9, seg 113 (tag 9), len/rad at junction (5.774) below 6.
Warn.: Wire 22, seg 391, len/rad at junction (2.405) below 6.

Also, 4NEC2 shows an AGT of 1.251 with this as well, which is no where near desirable.

Assuming you didn't have any of these problems in EZNEC, I wonder if there are differences in how both programs treat the same data?

The DB

My model shows very little difference when I remove the mast or isolate the mast from the antenna by a few inches. For me, this suggest there is so little current flowing in the mast that the resulting difference is very small. So, I would predict that when you add your mast you should also see very little change.

I can't be for sure, but your model looks to have a couple of data entry errors. When the segments on this segment errors report are corrected, the model should look a lot better.

The AG results should look a lot better too, if the source is connected at or near the middle of wire #8, a 2" x .50" wire with only 1 segment, and 1 (A) at 0.00* degrees of angle for the feed point.

Eznec only shows the AVG result with a FS model, and my model shows 1.024 = 0.10 db as a results. This is only a fair/good value. I believe this is why I see a 1.506 SWR, which could be better.

I forgot to post my PDF, FS model attached below

 

[The DB]

My model shows very little difference when I remove the mast or isolate the mast from the antenna by a few inches. For me, this suggest there is so little current flowing in the mast that the resulting difference is very small. So, I would predict that when you add your mast you should also see very little change.

That should be expected with a full set of radials. Sometimes it still makes some difference however.

I can't be for sure, but your model looks to have a couple of data entry errors. When the segments on this segment errors report are corrected, the model should look a lot better.

That was your model exactly as you posted it above. Every element and diameter and all exactly as you listed it above. I assumed you did all of that which was why I was surprised to see it. That is also why I wondered if there was a difference between out programs...


The DB

 

[Marconi]

DB, in the list what does the last value after the word seg stand for?
Example: wire 8, seg 110. Is this the number of segments for the wire?

My wire # 8 is only 2" long with 1 segment. This is where the feed point is inserted. Wire #1 is the radiator and it does have 85 segments and is 255.83" inches long. Wire #2 is the mount has 5 segments and is 12" long. Wire #9 is part of the trombone and is 6.5" long and has 3 segments. Wire #22 has 128 segments and is 384.75" long.

Beyond this I cannot help more, I really don't fully understand...except this is error reporting. If these are not the number of segments for these wires...what do they mean?


If this model has that many errors as reported...then there would be no way for the model to produce similar results...to say nothing about the possibility such a model might not even scan.

Could you post your wire descriptions for your model?

 

[The DB]

I'm pretty sure that is the total segment count including all the wires before that point. If you count all the segments before wire (or tag) 8 the one segment on wire 8 is segment number 110.

The data, as recorded and entered from above.

This is the data that created those errors in 4NEC2. Unless I missed something it is exactly the same as the data you shared above.


The DB

 

[Marconi]

DB, fix the 5 errors noted and hopefully the model will work right.