36.089 vertical antenna

[Coyoteman]

Has anybody out there made a full length 11 m/ 36.089 ft vertical antenna and if so how well did it work. Are there any instructions out there on how to make one? is it even feasible to make a 11 m full wave antenna. Be curious on how good this would do on DXing. How would the tuning the swr be on something like this. I would like to make something like this in for five or six section so I can take it down drive out to a good location with good altitude assemble it set it up in the bed of my truck and try some DXing. What do you think?

-- Wednesday, 03 September 2014, 19:16 PM --

Boy I don't little research just before going to bed and it looks like the horizontal dipole works the best for DXing. And those are really easy to make.

[231]

Full wave verticals don't have a very good angle of radiation which is why nobody makes them. Seems to me the .64 wave length was pretty much the limit before getting to diminishing returns. Horizontal polarity does sometimes work better for DXing, but not always. It just depends on propagation. Many folks do very well with vertical polarity. Having both at a flip of a switch is the ultimate though for those who love to chase DX.

Actually what works better than just a dipole is a full wave loop. Full wave loops aren't hard to field deploy either...especially in a Delta configuration (triangle). They don't absolutely have to be square or even perfect triangle to work well either. Matching them for a single band, I'm thinking a 1:1 balun...but I can't remember for sure? I've built them for multi-band use (80m-10m) using a 4:1 balun that worked outstanding.

There are instructions for full wave loops all over the internet. You can support the connection points with trees, and they even work well low to the ground (20' or so).

Good luck.

231

[The DB]

231 is right. For a single element about .64 wavelength is as long as a single element can get before a higher angle lobe becomes dominant. This can vary depending on various factors, such as ground conditions, and in most cases .64 wavelength really is beyond that magic length.

There are ways to extend the maximum length of the element some by angling the radials upwards, such as the old Avanti Sigma 4 and Big Mac designs, or the newer Vector 4k versions. There is a limit as to how long you can go, and 7/8 wavelength is as long as any mass produced antenna using said method has been. Many people will tell you that those are simple j-pole antennas, although others (including myself) have argued otherwise pointing to obvious flaws in that logic.

If you want a vertical antenna one wavelength long, or even up to 1.25 wavelengths long, what you can do is center feed it. It will require either a matching network at the center feedpoint, or perhaps open wire feedline to an antenna tuner for matching. Either way will work. Another note on this type of antenna, it is very sensitive the ground. For at least the first wavelength from the ground to the bottom tip height really is might, even more so than with other antennas, especially antennas with radials.


The DB

[-357Mag]

I'm a Big believer in a 1/2 wave inverted "V" with a 30' center height. They have plenty of gain and are a good compromise for Local & DX.

[MDYoungblood]

I am using a HyGain AV-6160, it is a 43ft vertical HF antenna and in my experience with it anything higher the 20m (and that is marginal) does not do well. Yes like said a quad loop or the delta loop for frequencies above 20m is the antenna to build or buy. I have a homemade quad loop for 11m, tunes 10m with no problem and 12 to 20m with a tuner. I have plans to make a multi-loop using a 4:1 balun like 231 stated.

3's

Greg

[231]

I'm a Big believer in a 1/2 wave inverted "V" with a 30' center height. They have plenty of gain and are a good compromise for Local & DX.

Ain't nothing wrong with an inverted 'V' but as far as gain, it's zero (0.0 db over a dipole) or +2dbi (over isotropic radiator) as a 1/2 wave inverted 'V' is a dipole, nothing more. You are right though...for folks in limited space, antenna restricted areas, or doing simple field deployment, etc. it's a great choice (especially as cheap as they are).

231