Spider beam :-(

:confounded:

Morning.
As some of you know one is in middle of building a spider beam to improve me station here. After putting the support legs on, came the horrible shock of the size of it OOOOPs :open_mouth:

Garden is not big enough :scream:

So back to drawing board. :blush:
Now looking into building a hex beam instead. :flushed:
This leads me to a Question on the spider has a 4:1 balun, do I still put one on the Hex Beam.

Thanks again for your Time and attention :wink:

Karl

Not the easiest antenna to setup correctly Karl… Especially if your HBrewing it is also difficult mechanically as you will need to make a suitable hub.

Why don’t you consider a omni directional antenna such as G3TXQ’s Cobweb ?. You do not need a rotator with this obviously. There are other variants to consider also. Its particularly compact as well.

I built mine in roughly two weeks, I am pleased with it.

Jonathan.

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Hmmm nice idea

Tuning of a spider can be just as tricky.

Trouble is I do want a direction beam and when started spider and then found need to stretch the garden bigger LOL.

Thanks for your input and that could be good idea for a portable antenna/ Sota Portalbe

Karl

With SOTA judging by most chaser’s logs you change bands fairly rapidly from working one person to the next. Which will also mean you will have to rotate it in a similar fashion. KISS springs to mind. You could upgrade your license progressively and get the the extra x.dB in Tx capabilities and have an omni directional pattern. Win Win.

A Cobwebb is too big for portable use … You would struggle to balance that with two arms, never mind carry it up a hill. A Hex Beam is even more cumbersome. These are not small structures. Some that do use it for portable use carry it with a large van.

You have look at the practicalities with antennas all the time. Especially the safety aspect.

Jonathan

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Cheers for that.
Not worried about rotating the antenna.
Going to be fun at first run downstairs into garden turn beam by hand back upstairs till one can get hold of a rotator
Want some more directional like the spider. but its too big.

This is for home base using the hex.
Just need to know should I add the 4:1 balaun
Karl

Have you considered two quarter wave verticals separated by a half wave and linked by a variable phasing coil, this permits you to steer the lobes and nulls as if you are turning a beam. The gain isn’t high, probably around 3 dB but the nulls can be used to reduce interference. There is more on this option in the Handbook. It would take up a lot less space and be less visible than a horizontal beam and save on a rotator. Use a small number of elevated radials rather than high numbers of buried radials…and grow clematis up them if you get complaints! :smile:

Brian

Oh my that is technical for me
Any web site one can view this one please so gain a better
understanding.

Don’t give me ideas, missus would love that :slight_smile:

Karl

Yes, mine did!

A few web references:
http://lists.contesting.com/_towertalk/2006-04/msg00143.html
http://www.moneysmith.com/W4NFR/40%20Meter%20Phased%20Verticals/40mpv.html
http://www.w6kan.com/5.8wlverticalantennas.html

You can scale the design for whichever band you want to use, and if you have just one preferred direction you can dispense with the switching and just cut the phasing coax to favour that direction. The design in the RSGB Handbook uses a tapped coil and a selector switch to move the lobes about at will, but it is a bit short on detail.

Brian

Lovely thank you

karl

Hello Karl,
I have sent you an email.

To answer your question here for the thread - you do not need a balun for a co-ax fed hexbeam.

As mentioned above there are two components that are crucial - the hub and the centre post. Cumbersome - Hmmm -well here is me building my hexbeam on a sunny and wind free day :wink: I am six feet and three inches tall so it gives you an idea.

Cheers
Mike

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Cheers mike

Nice legs LOL
Its smaller than the spider by about 12ft and will fit in garden

Karl

Thats what I call a mast !

Hello Karl:
Let me propose you a small directional antenna which won’t require a powerful big expensive rotator:
The TAK antenna: YF1AR yankee foxtrot one alpha romeo: June 2012

You can also find it as TAK-TENNA.
Best 73 and good luck!
Guru

While the phased verticals and the Tak-Tenna sound interesting, I think these are single band antennas and Karl is looking for mutiband I believe. I think the Hex Beam or Cob-web may be the answer.

73 Ed.

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Right on ED

I may not have 6 12 and 17m at the moment but will be installing them on the hex as it becomes a 6 band antenna. Where the Sota,s wander across the bands , I try to follow. Plus the hex is light weight and be hand rotated for a while. Just got to save some more pennies get bit more gear in and see me chef at local pub about couple more catering chopping boards which are big enough to cut down to size and well thick and strong for the centre piece for the Home brew antenna I now have in mind.

Plus going to choke it too, cant have stray currants loose can we now :smirk:

Karl

Hi Karl,

here is an small beam: www.foldingantennas.com

I have used this antenna at a lighthouse activation. It performs very well.

73 Lutz

Lutz thanks for that.
Been and had a look at the web page.

Interesting giving me ideas that :slight_smile:

Karl

Hello Lutz, the folding hexbeam is reviewed in the current issues of Radcom.
Cheers
Mike

Don’t get fixated on beams, Yagi, Hex or other. You do need to get them high for them to work well. You can make omni verticals for pence. You can make steerable verticals for pence. You can make electrical steerable verticals for more pence!

Looking at your chaser log and the countries chased would suggest to me your G5RV is too low and pointing the wrong way for US/VK stations. If you have a 7m fishing rod you can make a 1/4GP (4x 5m pieces of wire) which will give your TX signal a better take off angle. It may well be noisier on RX than the G5RV but you can always switch between the 2 for RX and TX. Yes, I know you have only got 10W, but I only have 5W and can (if I’m about at the right time) work DX with a few metres of wire.

The comment made me curious. Good use for Log2Map :wink:

Here is the result:
http://www.on6zq.be/p/Log2Map/index.php?log=DnzXd3xAsQ1mXV05HrN774Xaoyc

2 Likes