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Windy weather


#1

I am new to SOTA; I activated my sixth summit today. So far all one point hills. Can I bother people with a few questions.

On Friday I activated Garway Hill in the Welsh Borders, a nice open hill with good views. The weather was dry but breezy. I had alerted for 2M SSB. On putting up my Sota beam on it’s fishing pole mast I was worried to find the mast bending quite alarmingly, and the beam pointing down towards the ground at an angle of about 30degrees. Also regardless of where I pointed it, the beam worked it’s way back to pointing to Bristol. My walking companion prefers to stride off over the hills (she gets cold) so I didn’t spend long trying to to sort the antenna out and instead resorted to the rubber duck. I made the four QSO necessary to qualify the hill, with more effort on the chasers part.

What do others do in such conditions? After all this is only a one point hill, and it was hardly a gale.

Thanks
Richard
G0IBE


#2

In reply to G0IBE:

Hi Richard

Surprisingly others also end up with their beams pointing at the ground or the sky at 30 degrees in windy conditions. You could try guying your pole at a higher point, or carry a reserve antenna such as the roll up J pole type in case of high winds. Another tip is to set just the driven elements of the beam up as a dipole, this offers less resistance to the wind.

73
Mike GW0DSP


#3

In reply to G0IBE:

Hi Richard

Thank you for working me the other day,

I have just finished activating the Welsh borders and i do no how you feel.
Not only have i had the same problems but ive managed to forget my boom before for my 4 ele yagi , as GWODSP has just said use the dipole of the beam if needed.

My Windy Antenna set up=

4 Ele home brew yagi http://www.mydarc.de/dk7zb/start1.htm
Moddified old tripod
3 guy wires for the tripod. Pic here http://i10.photobucket.com/albums/a128/infinitycorsa/DSCF4349.jpg

Normal conditions

4 ele home brew
Large sota pole guyed, but guyed higher

ALl for 2m ssb

HF Antennas to come once i have found a light battery!

2E0VXX

Tris


#4

In reply to M3VXX:

HF Antennas to come once i have found a light battery!

No wonder you want a light battery… that tripod setup must weigh a ton! :wink:

Andy
MM0FMF

p.s. You don’t need the [IMG] tags on here.


#5

In reply to MM0FMF:

img tags removed

The Tripod isnt that bad actually, with the beam… the radio was an issue and so was the battery… the radio has been solved and changed from an trio 9000 to an 857, but i need a light weight battery to support it.


#6

I wondered about using a tripod. The picture makes it clear how you have it arranged. Thanks. Have you any idea how much the gain is reduced with the loss of height say from 4M to 1.25M?

The J pole sounds worthwhile too. After Garway Hill we moved on to Graig Syfyrddin, which I activated on 2M FM, and struggled a bit with no alert and no spot. A J Pole would have increased the range. I will add this to the list of things to do.

Thanks
Richard
G0IBE


#7

In reply to G0IBE:

Hi Richard,

You didn’t say whether you have an SB3 or an SB5, but either way they both swing well in the wind. I find that lowering the mast helps, even bringing the antenna down to 2m - you’re hundreds of metres up and hopefully in the clear anyway. You can strap the sections of the pole together temporarily using electrical tape. The problem with this method is when it is raining heavily, for obvious reasons - then I generally use a small bungie. If it really is very windy, then just use a dipole as Mike has suggested. The back section of the SB5 is well suited for this purpose.

There will be times when you can’t safely get a proper antenna up anyway due to there being too many people around, for example on Sugar Loaf Mountain (hint: get there early - I didn’t!). You’ll soon learn to play it to suit the situation.

Hope to work you soon.

73, Gerald


#8

Thanks for the ideas. I will add insulation tape to the kit I carry.

I don’t do ‘early’. I usually manage to faff around all morning and leave too late. I then get pitying looks from those descending, and surprisingly often get asked if I have a torch.

Thanks for the comments.

Richard
G0IBE


#9

In reply to G0IBE:

In strong winds I simply attach a tether to the front of the boom (pegged some distance away). That keeps the beam on the required bearing.

73

Richard
G3CWI


#10

In reply to G0IBE:

Hi Richard,

Pleased to hear people are concerned enough to make enquiries. Most people you find up summits are sensible and caring. The idiot fringe generally only appear on the popular hills such as Snowdon, Cadair Idris, etc.

A torch really is an essential item of kit, even if you aren’t intending activating at the fringes of daylight. You never know whether you might get delayed by something as simple as a twisted ankle, particularly if you are activating alone. What individuals take up the summits is a matter of personal preference - the subject has been discussed several times, so you might like to check back on the reflector.

As for holding a beam on heading, I have also used a lightweight rope and peg, but it’s a pain when you’re called by someone who can barely hear you off the back of the beam. On one occasion the beam moved around so much it pulled the peg out of the ground several times and it became a constant battle. In the end I let it go with the flow and wondered why I’d bothered!

73, Gerald

Some photos of relevance:

  • even a small beam can bend a SOTApole
  • the coax gets in on the act (that mast is ally)
  • desperate measures

#11

In reply to G4OIG:

For windy weather I sometimes wonder if the answer is a Turnstile. Horizontal polarisation, slight gain, omnidirectional, no worries about turning the beam. Its worth thinking about.

73

Brian G8ADD


#12

In reply to G8ADD:

slight gain

A turnstile certainly has more gain than a dipole off the ends of the dipole but not compared to the dipole’s main lobe. Cebik describes why this is.

“Despite having a single elevation lobe, the maximum gain will still be about 2 dB lower than the maximum gain of a single dipole. However, the single dipole has only 2 lobes, whereas the turnstile has 4 overlapping lobes that form its omni-directional pattern. To fill the dipole “gaps,” power has to come from somewhere, and it is from the maximum lobes of each dipole. Hence, slightly less gain for the turnstile, but gain in every direction around the compass.” LB Cebik from http://www.cebik.com

Free lunches (or lack thereof) spring to mind.

73

Richard
G3CWI


#13

In reply to G8ADD:

Of course a halo is the simplest solution Brian and reasonably easily constructed - making it totally collapsable would make an interesting project. Incidentally, I’m thinking of making a 2m Moxon rectangle for use on windy days, along with a 70cms version. The one being held by Zvone S57OPZ in the report at http://forum.hamradio.si/viewtopic.php?f=48&t=7365&p=31588#p31588 looks sturdy enough to withstand a good number of activations.

73, Gerald


#14

In reply to G3CWI:
Ah, now I thought its improvement compared with a halo was due to compression of the vertical X-section of the lobe! I’m out of date, I guess! Still, they would be easy to stack, just mount each turnstile on a tube to fit the relevant section of the roach pole.

73

Brian G8ADD


#15

In reply to G8ADD:

Have you given any thought to carrying this paraphernalia up the hill Brian?

73, Gerald


#16

In reply to G4OIG:

Why do you think Brian prefers to have his wife along?


#17

In reply to G3CWI:

Why do you think mine won’t come along with me!


#18

In reply to G4OIG:

Two halfwave dipoles hinged at the centre for packing plus coax phasing doesn’t sound any more difficult than a beam with boom, Gerald, probably easier to assemble than some beam designs! Incidentally, the RSGB handbook gives a 1 dB gain over a dipole at the “corners” of the polar plot. Not much but 4 dB better than a halo.

73

Brian G8ADD


#19

In reply to G8ADD:

Corners? What sort of circle has corners?


#20

In reply to G3CWI:

A squared one?:slight_smile:

No, the polar plot is not a perfect circle but for all practical purposes we can act as if it is, just like the halo which has a slight “improvement” (I can’t really think of it as gain!) in one direction.

73

Brian G8ADD