My Lightning 6 Quad antenna

[Marconi]

I was impressed as well when the 3.5" feed point attachment was the sweet spot for the horizontal side.

When my matcher idea started working for the model I had the idea that the SWR bandwidth scans looked somewhat similar to what you reported. Albeit the heights were different I was also impressed.

Thank you for all your help with the dimensions.

When I started modeling the physical matching networks the only data I had to compare my results was if I could get the bandwidth near to what the manufacture reported. Then, if the BW was similar...I felt like the model might be close to correct.

The tap point locations also seem similar to what you report. However, I did a Free Space model on the vertical model and had to readjust the tap point to get the Average Gain results to improve. I'm not happy with the AG value of 1.053 but I did not fiddle with the segments either. I may be able to get it better with a little tweaking of the segments.

I think LA quoted me the 1.5 SWR BW.

Dennis, I had a thought that maybe LA looked at something different in their bandwidth report too, but a lot was going on and I forgot about the question.

My eyes are bad and I have trouble with little details and you were back a little for from the screen for me. I could not tell what you were focusing on in the video. I'll check it our again.

Below is the set of models for the Vertical side of your L4+. All I did was setup the antenna to your specs as best I could. I also added my idea for the physical matching device used for this antenna.

1. is in Free Space
2. is at 36' feet
3. is at 10' feet

Below is the setups for the Vertical side of you L4+.
1. is in Free Space
2. is at 36' feet
3. is at 10' feet

I also changed the title name to "L4+Vw-match 28.7mhz FS" and at 36' and 10' feet.

 

[dennis4040]

What do you think overall?
The gain is about what I expected, the front to back is not great but that is not to critical for me.
What is this spec? AG value of 1.053

 

[dennis4040]

However, I did a Free Space model on the vertical model and had to readjust the tap point to get the Average Gain results to improve. I'm not happy with the AG value of 1.053 but I did not fiddle with the segments either. I may be able to get it better with a little tweaking of the segments.
.

I found this so I understand a little bit of what u are talking about.

"Folks who have studied this issue suggest that a valid range for the Average Gain is 0.95 through 1.05. Beyond that range, confidence in the results starts to drop."

Considering the complexity of the dual polarity feed I think it looks pretty good overall but I have never done any modeling.

 

[dennis4040]

I have raised the L4+ to about 12' to the boom.
SWR and resonance is very similar on vertical and horizontal.

 

[jessejamesdallas]

So dennis4040, been a while now since you got the L4 up....How's it doing for you? Had any problems? Just stumbled on this old thread that's over a year old now, just wondering how everything went...

73's JJD back out.

 

[murdog]

Some poor photos of the L4+ assembled and analyzer sweeps of vertical and horizontal. Just a starting point, I probably need to get it off the ground to get a better idea. The baluns are temporarily attached until I get an idea where they will be when properly tuned.

Hello Dennis , Well I guess I ended up with a five element , guess they cut off the sixth , can I get you to post the manual ?now that I know what I have will try and make it a six again .

 

[dennis4040]

So dennis4040, been a while now since you got the L4 up....How's it doing for you? Had any problems? Just stumbled on this old thread that's over a year old now, just wondering how everything went...

73's JJD back out.

JJD,
I am very happy with the L4+. I am more of an experimenter than an operator and I wanted to see what kind of distant ground wave or some would say direct wave contacts i could make on 10 meters. Recently I became aware of a net in Omaha on Thursday evenings at 8pm 28.350 and have made contact consistently with 2 gentlemen in that net. They are 185 and 196 miles from me as the crow flies, and they are using between 100w and 150w with horizontally polarized yagies. Tri banders I believe. I'm running legal limit. Have made several 135 mile contacts to vertically polarized omni stations. The amazing thing is that it is usable on both 10 and 11 meters without a tuner. This would seem to indicate that it would have poor performance but I have been happy with it. Works ell on DX as well. The boom is at 110' which certainly helps.
It appears to be pretty durable as just this afternoon we had high winds that took out my 2 meter beam and looks like it has bent the top section of the 45g with a Voyager hazer.
The L4+ appears to be undamaged.
Looks like I have some work to do.

 

[dennis4040]

Hello Dennis , Well I guess I ended up with a five element , guess they cut off the sixth , can I get you to post the manual ?now that I know what I have will try and make it a six again .

Murdog,
I have this L6 manual I got from Marconi, hope it helps.

 

[dennis4040]

As a side note on the L4+. Thanks to Marconi I have a great eznec model of the antenna but would like to put a call out to the 4nec2 experts on the forum to see if it can be converted and the variables setup so we could take advantage of the 4nec2 optimization feature. Does anyone have an interest in doing this?

 

[Captain Kilowatt]

JJD,
I am very happy with the L4+. I am more of an experimenter than an operator and I wanted to see what kind of distant ground wave or some would say direct wave contacts i could make on 10 meters. Recently I became aware of a net in Omaha on Thursday evenings at 8pm 28.350 and have made contact consistently with 2 gentlemen in that net. They are 185 and 196 miles from me as the crow flies, and they are using between 100w and 150w with horizontally polarized yagies. Tri banders I believe. I'm running legal limit. Have made several 135 mile contacts to vertically polarized omni stations. The amazing thing is that it is usable on both 10 and 11 meters without a tuner. This would seem to indicate that it would have poor performance but I have been happy with it. Works ell on DX as well. The boom is at 110' which certainly helps.
It appears to be pretty durable as just this afternoon we had high winds that took out my 2 meter beam and looks like it has bent the top section of the 45g with a Voyager hazer.
The L4+ appears to be undamaged.
Looks like I have some work to do.

Looks like too much windload too far above the tower and not enough mast inside the tower. For that kind of windload you should have the rotator about 8 feet down from the top. This GREATLY reduces the bending moments on the tower.

 

[murdog]

Murdog,
I have this L6 manual I got from Marconi, hope it helps.

Thanx Dennis

 

[nomadradio]

The way this antenna behaves with polarization still baffles me.

The feed wire attached at the bottom is the vertical feed. The feed wire on one side is the horizontal.

Pointing it at a vertical antenna or a beam with dipole elements gets you a big difference switching between feeds.

Pointing at another antenna built like this one shows almost no difference when you switch feeds.

There have been about 200 copies of this "Frostbite Stinger" antenna put up around these parts over the last 20 years. Had the occasion to try this more than once. It's built like the Lightning 4, but with wires instead of solid rods.

Can't figure out why it treats the polarization of one antenna differently from another.

Never did try to contrive a fancier test that could shed any light on it.

Does seem to make it a good skip antenna, but I sure don't know just quite why.

73

 

[wavrider]

DAMMMNNNNN hope you do not live in a windy location

 

[jessejamesdallas]

Looks like too much windload too far above the tower and not enough mast inside the tower. For that kind of windload you should have the rotator about 8 feet down from the top. This GREATLY reduces the bending moments on the tower.

That's about where my rotor is mounted...about 1 to 2' from the bottom of the top section of the tower...although I don't have anywhere near the wind load Dennis has, I also have never had any wind related damage to the tower or mast.

 

[Captain Kilowatt]

With my planned antenna installation this summer/fall I will have about 23 sq. ft. of antenna surface spread out from directly above the tower to about 14 feet above it. I originally planned to have the rotator about four feet down from the top but with some changes I made to the antenna stack decided to move the rotator down to about eight feet from the top to avoid kinking the top of the tower. It's a fairly heavy duty 64 foot Tyrlon T500 but with extreme winds we get on the rare occasion why take chances.