Base lightning antennas l4+ quad

[21AT555]

Yes, that's right, the idea is a copy of L4 +. I do not have the old instructions from SE. I have it from LA + the pdf I got from you. Now I have put my home building up in a mast about 50 feet above the ground and it seems to work, not so much noise or swr. It is much quieter in the noise than my old 4 element yagi was. So yes it seems to work.

 

[Marconi]

Yes, that's right, the idea is a copy of L4 +. I do not have the old instructions from SE. I have it from LA + the pdf I got from you. Now I have put my home building up in a mast about 50 feet above the ground and it seems to work, not so much noise or swr. It is much quieter in the noise than my old 4 element yagi was. So yes it seems to work.

555, did you record ALL of your dimensions for the quad you have up?

If so, please post what you have recorded or send them to me using a Personal Message, ie., the Conversation feature on this forum.

 

[Marconi]

Marconi. The length of the spreaders are not the problem, i bought the hole wire set, so from there i could figure it out . It´s the distances between the spreaders i am a little confused over. But i will start with the pdf you so kindly handed over to me. Tnx /Janne

In the PDF files below is an email and a picture of an L8 from a radio buddy, about 70 miles SE of Houston, Texas, where I live. Make of it all...what you will. This is for more information, but I don't agree with his stretching the wires.

555, the instructions tell us NOTHING about stretching the wires prior to installing. If I said anything like this earlier, I was wrong.

You will see in the email from Harvey, that he mentioned stretching his wires. Some antenna Quad manufactures tell their customers to stretch the wires, but Signal Engineering and Lightning Antenna's say NOTHING about stretching their wires.

Were your replacement wires color code to identify where each wire went along the boom as noted in the manual?

Below is the Patent too.

 

[Marconi]

555 and other's interested in the Lightning Antenna L4 quad 4 element beam. I was able to get the horizontal polarity setup working, but it falls short of the reported gain and rejection.

The question is, "...have we heard this before."

Model:

1. notes and the model showing the tweaked dimensions that produced a small loss in gain...but a whopping increase in the rejection. This may be important to some operators in you want to experiment a little.

2. This is the model that I got dimensions from a couple of radio buddies. Their numbers pretty much agreed on most of the wire dimensions for the L4+ antenna at 27.205 MHz. The first 4 pages are images of the antenna showing one side length for each of the 4 elements in the L4. I posted the spacing earlier in this thread.

Click here: lightning antennas l4+ quad

3. I included the overlays for these 2 models so we can compare the performance differences in the models. Maybe 555 can use this to make his homebrew L4.

 

[Marconi]

Here are some overlays of 4 element beam type antenna models to compare for the difference in performance.

Again we see very similar results, even though manufactures tend to always claim better performance for their design.

IMO if you build your beam for maximum gain, you will likely never see much difference when comparing it to some other similar antenna. That is unless something is wrong with the coax or one of the antennas construction.

If you build for maximum rejection, the improved rejection can show a big difference in performance of your beam and typically the reduction in forward gain will be minimal, so you don't give up much to have a tight back door.

 

[Marconi]

Here is a model from Henry HPSD in Holland. IMO this is the best beam model. Has more gain than the others I posted above and has very good rejection. It is direct fed with no matching device which has to add a little loss to any antenna with a matching device. This might explain the modest increase in gain we see for this design.

Only problem will be setting and supporting the angle for the driven element...which is slanted back - towards the reflector a bit. I call it a center fed Gull-Wing yagi.