Hexbeam receiving in other directions

Question

Have a K4KIO Hexbeam up at around 20-feet on the corner of a flat metal roof pointing at 290-degrees bearing (Europe, from Sydney Australia). Currently the Hexbeam is fixed to that direction as i don't yet have a rotator, and it's fed with ~25M of RG8.

There's also clamp-on ferrites at the feedpoint (supplied by K4KIO) and at the radio end.

Being pointed to Europe it works as i'd expect, but i also notice it receives USA as well which is off to the side of the antenna by a fair amount, when the band is open (on 40M & 20M mainly).

Even compensating for a very wide beam-width, the fact the Hexbeam is a 2-element beam, and not very high, it's interesting (to me anyway) it receives USA quite well when not pointed in that direction.

I work FT8 alot and can see via the pskreporter website this is the case. This happens regularly.

Was just wondering if this is a propagation phenomenon, a factor of it's current height, or something deeper i need to address?

Thanks.

Answer 1

Looking at an azimuthal map centered on Sydney, Europe looks to be at about 300° and the USA looks to be at about 60°. So if the antenna is pointed at Europe, then the USA is about 120° off to the side.

Looking at an antenna gain plot of the K4KIO hex beam from K4KIO's web site, it looks as though the gain in the direction of 120° off to the side is about 11 dB lower than straight ahead. The plot doesn't specify which band it's being used for, or how high the antenna is, but since it's for marketing purposes, we can assume that the plot attempts to put the antenna in the best possible light, which probably means 20m with the antenna up high.

So the best-case rejection of the USA compared to Europe for your antenna is 11 dB, which is about two S-units. Since your antenna isn't up as high, and is used for 40m some of the time, you probably have less rejection, especially on 40m. This sounds like fairly normal behavior for your antenna.

Answer 2

I used a Traffie Hexbeam antenna for about 12 years. Even though I had a rotator for the antenna there were many times that I did not move the antenna in the direction of a given signal because I could work them just fine. Sure, if I rotated it, I might get another S-unit on receive or even 2 S-units but I was lazy.

I found that working off the side was not a big problem, the directivity of a hex beam, especially at the 35 foot elevation I had was not that great. I think front to back was about 15 dB or so. Rotating front to back though was about 15 seconds so if I could work a station, I never bothered to rotate.

I gave the hex beam to a local ham radio club so that they could use it as a portable antenna for Field Day and other activities.