Years ago when I first showed an interest in radio, a very senior radio ham said to me “son, there’s more garbage talked about antennas than any other subject in the ham radio world” (actually, he didn’t use the word garbage.)
One thing that has always puzzled me since being licensed, is how a vertical on the HF bands even using low power, will absolutely beat a beam hands down.
Today was a classic example, as if by some type of sorcery, my vertical CB antenna just punched straight through almost every pile-up on both 10 and 15 Metres.
Low angle of attack is one of the common reasons I’ve heard.
I did a little Googling and came across and I quote…
"As a general rule of thumb The lower the angle of radiation, The further DX you will work.
And the Higher the angle of radiation, the closer dx you will work.
This also becomes null when considering what frequency you are referencing. The higher the frequency the less effect the atmosphere will have."
Now this doesn’t exactly explain, why a cheap CB antenna should beat very expensive beams using big power. …Ok certainly by no means every day, but just occasionally there are days when my vertical works more like a magic wand than an antenna and today seemed to be one of those days!
Yes it could be possible for a decent vertical to have more low angle radiation than a low mounted yagi for the HF bands. Play with some antenna modelling software like MMANA and you will see what I mean. Add some seawater nearby and you are really “cooking on gas”.
For instance if you gave me the option of a vertical for 20m (EFHW or 1/4 GP) within a few feet of the sea versus a 20m 3 element yagi at 10m high, I would take the vertical any time (for DX) as it will have a lot more radiation at low angles (enhanced by the seawater GP). You would need to put the yagi very high up to come close.
Even over normal ground the vertical might seem better for DX as a lot of the more “local” QRM (say Europe) will be weaker.
If you can put a vertical beam (like a Moxon) next to the sea… the sky is the limit. Have a look at this link:
I am sorry to say that your success would be down to conditions more then the antenna IMHO!
In my profession of Shortwave Broadcasting, we would never dream of using a vertical antenna! Look at any Shortwave Broadcast site and they will normally have Log Periodics, Conifans for NVIS or in most cases Horizontal, Stacked Dipoles for Single/Dual or Quad Band Operation. Normally these will have Reflector Curtains and about 10 degrees beam width and take off angles of between 7 and 15 degrees. We generally try not to waste 250 Kilowatts of power, it needs to reach its target audience.
The Dipoles are often stacked in columns and rows of 4, I have also seen antennas of 8 dipoles wide at ex USSR sites! Typical gain of the 4x4 is 22dB! This is genuine gain not this mickey mouse dBi figure that all manufacturers quote! Never take these dBi figures seriously they are complete tripe!
IMHO A beam will destroy any non directional vertical, you can squirt the RF in a preferred direction!
I am glad to hear you have done well on HF, but think how well you would have done with a beam! Conditions have been very good on HF recently!
This is why I use VHF/UHF on the hills as I spend to much time playing on HF professionally! Less hassle and VHF benifits so much from Height! Why walk up a hill and not use the advantages that it brings to you!
Thanks for the very useful link, Marc. I’ve read some interesting articles about antenna and sea water over the years. When I was A kid, I lived about 800 Metres from the seaside, now I’m licensed, I couldn’t live further from it
I am sorry to say that your success would be down to conditions more
then the antenna IMHO!
snipped for brevity
Thanks for the comprehensive reply, Matt.
I am glad to hear you have done well on HF, but think how well you
would have done with a beam! Conditions have been very good on HF
recently!
Conditions have been good, with some normally difficult to find DXCCs about.
This is why I use VHF/UHF on the hills as I spend to much time playing
on HF professionally! Less hassle and VHF benifits so much from
Height! Why walk up a hill and not use the advantages that it brings
to you!
Must agree, VHF is great fun 2k feet ASL. As for UHF, not done an awful lot, however, you just may have put an idea into my head
In reply to 2E0YYY:
I must put my 2c in and say verticals have their place for portable and low band’s. but from a dx point of view a beam wins hands down, being able to “squirt the rf” in the right direction in stead of all direction’s has to be better. However if using phased verticals, such as the 4square method, it has a slight advantage in that you can change direction instantly rather than waiting for the beam to turn. It’s not as good gain but handy for dxpedition’s as you don’t need towers/rotators etc
If you know where you want to squirt your RF, a beam is the way to go, & the more gain the better. Sometimes though, an omnidirectional antenna is better, especially if band conditions are good. I remember very well hearing a very nice DX station repeatedly calling a UK station with a good 7 element yagi. The yagi was pointing in completely the wrong direction for the DX that was calling & the UK station had no idea they were there.
My simple half wave omni-directional vertical enabled me to not only work the DX, but help the other UK station turn his antenna the right way to get him another new DX entity.
The frequency (or wavelength) you are working on have a big part to play, & while it is very easy to get a VHF yagi a full wavelength or more above ground, the same distance may present problems for most people on 80m, & certainly on 160m. Notwithstanding the planning problems you would have, you would also need a fair bit of space to securely guy any tower(s)you intend to use.
A 1/4 vertical ground plane antenna for 80m or 160m will probably be the most any amateur in the UK could hope to erect for the low bands, & with a bit more space you could probably erect a four sqaure phased vertical array.
Beyond that, you would need a lot of space & no neighbours.
If you can get your MF/LF beam up high enough then yes it will work, but a vertical on a good ground plane, will have to do for us mere mortals.
When they de-commissioned Rugby, & demolished the towers I was upset, I always fancied that as my future antenna farm. Well, Bagsy first dibs on DCSA Inskip when that is eventually de-commissioned! Hi!
In reply to 2E0YYY:
Yes conditions have improved, yes height works wonders with VHF and UHF but it also has the same effect with HF especially if using verticals.
In reply to G0VOF:
Yes, in theory a beam is better, but you also need plenty of height, and at the sort of height most of us can manage beams will fire uncomfortably high above the horizon - even if you can persuade the planning authority to let you put up a mast they will probably balk at a wavelength at 20 metres! I really doubt that a beam on the chimney of a semi will outperform a vertical with plenty of radials, at least on long paths.
With verticals for 20m, 17m and 12m on SOTA activations, I have worked USA, Canada, Argentina, Nigeria, Japan, Australia and East Malaysia amongst others. With results like that from 5 watts and four quarterwave lengths of wire, I have no desire to cart an HF beam up a hill.
