I was watching DXCommanders little video on his vertical beam for 40m and And idea started. At our club we have quite a large field and putting up a multi element beam for 20 or 40 would be possible. Could be ten element maybe more. Does anyone with the eznec prog feel able to model such a thing for me to give dimensions?

I'm sure if you drop Callum a message or comment on his video he would do this. Could end up being the subject of his next production!

Good call. He's done it already. He actually sells three ele vertical beams...

NEC will give you a fair approximation, but it won't be cut to size and just use, the ground will make a big difference, so what would you use for the model?
It will also affect the feed impedance, so some sort of matching, or adjustments might be needed.

There would probably be little point in initially modelling so many elements until the first 3 or 4 had been built and tuned.
And then I doubt if extra would give you much return for the money and effort.

It does take quite a long time to model even what seems like a simple antenna, and optimise it for the parameters you want.

I have had great success with Yagis dual band single feed Yagis and some other verticals, and most times the perform exactly as calculated.

I would not offer to model yours, as I have no way of checking the results (unless I build one in the street), so any questions afterwards would not be able to be answered.

However, it would take an average person much less time to learn enough of the programme to do it, than it would for some one to actually model it. The only manual calculations you may need are to work out angles and sides of a triangle, so if you know the meaning of SOHCAHTOA you're away

Give it a go, you won't regret it

SOHCAHTOA...i *DO* indeed.

Looking at Collins site he has done all the work and sells kits for 3 ele40m vertical arrays. They're not overpriced but even so, I have enough kit here to go ahead and make one.

I'd get quite a thrill being able to say my aerial was a three ele beam on forty!

Thanks steve

I thought you would

You would only really need it if you wanted to model the radials as well.

There are lots of articles on the idea, it would probably be best to "average" them and start building.
You won't need to alter the lengths much (easy to do anyway) then when you are closer, you can model it if need be, modelling comes in really useful to adjust the spacing to get a balance between F/B, gain and feed impedance.

I'm not certain if the ones on the site mentioned give the gain as dBi or dBd (to many words compared to facts on the site, got bored with reading it), but a 2 element phased array would give north america and Africa, with a convenient null to Europe. Unfortunately it would give a null towards south America as well.

And if you are going above 3 elements, the old 4 pole array is useful and steerable.

So many nice projects if you have the space

Lucky to have the field. (wonder what the flying club would say if I set up wire antennas on the patch )

Lucky to have the field. (wonder what the flying club would say if I set up wire antennas on the patch )


Tell em it's a limbo contest...

That vertical 3 ele is a neat little innovation if you just want gain in one direction such as the states, but a bit of a compromise if you want to work other directions. I've played with a couple of phased verticals on 40m using just coax and a T-piece to feed and you can reverse the directivity just by swapping the phasing leads - the patterns don't seem that sharp so had it firing east-west for USA and Asia, and the gain was enough to be hitting USA RBN stations right though daylight. A 4-square would be even better but you need two more verticals and the switching unit, I found the 2-ele a nice step up from a single vert without being too onerous.