The simplest QRP HF portable antenna?

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Re: The simplest QRP HF portable antenna?

Post by Ivan on Tue Jun 03, 2014 7:51 am

The link is hidden uder the word "poles" in my previous message. It seems almost invisible.

VBR from Ivan

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Re: The simplest QRP HF portable antenna?

Post by Ivan on Tue Jun 03, 2014 7:48 am

OK5IM offers fibre-glass (non-conductive) telescoping poles up to 15 m long, tested as antenna supports. They can be erected by one person. The pages are in Czech only - sorry. Prices are in CZK, prices in EUR = approx. 30 times less.

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Re: The simplest QRP HF portable antenna?

Post by Admin on Sun May 25, 2014 12:14 am

No problems, I have plenty of time.

Interesting comment on the Mag-Loop antennas. I could have something like that mounted on the car. Only disadvantage would be the narrow bandwidth and tuning it. But I am sure I could make something out of coaxial cable, possibly with a multi-band unit having one feed loop and several resonant loops.

Best regards from Harry - SM0VPO

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Re: The simplest QRP HF portable antenna?

Post by DragonForce on Sat May 24, 2014 4:40 pm

Hi Harry

Sorry for the delay - no diagrams for the DV-27 antenna exist as such, I will attempt to draw something later in paint shop pro and see if it makes any sense.

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Re: The simplest QRP HF portable antenna?

Post by qrp-gaijin on Sat May 24, 2014 2:31 pm

Have you considered a portable magnetic loop antenna? Here are a few links.

http://www.g4ilo.com/wonder-loop.html
http://rsars.files.wordpress.com/2013/01/qrp-loop-tuner-80-20m-g8ode-iss-1-32.pdf
http://www.alain.it/2011/06/15/ww3ww-portable-magnetic-loop-antenna/

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Re: The simplest QRP HF portable antenna?

Post by Admin on Sat May 17, 2014 6:59 am

Di DF,
Now that also sounds like a good idea. Perhaps one could spend a bit on materials and get superior performance. Do you have any pictures or drawings?

As regards the ground-plane, my main reason is that the ground itself is unpredictable, sometimes sand, sometimes rock, and very rarely wet soil. This would mean that a (Earth) ground-plane would be unpredictable, but that which you propose could also be elevated by 4 metres and not rely on the soil properties.

Only disadvantages I can see are price, assembly time / support method, and omni-directional properties.

Comments noted about the fishing pole. I seem to recall fibre-glass poles available, but when I read I van's ideas I also thought about wind-surfer masts: just a more robust. Unfortunately components for "leisure activities" seem to tripple in price and boating/surfing is no exception.

I will investigate all three ideas a little further.

Thanks for the ideas :-) Harry - SM0VPO

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Re: The simplest QRP HF portable antenna?

Post by DragonForce on Sat May 17, 2014 1:48 am

An average "fishing rod" is maybe 10 to 15 feet in length, and can be found made of split cane (very heavy) with maybe a steel core, or glass/carbon fibre.

If you need a long length, you might want a "roach pole" - those can be up to some 20 METERS.  Only problem I can think of is that the modern day ones are made from carbon fibre.

I've often thought an umbrella basket would make a good ground plane Very Happy

I know you want portable and no ground plane, but a good portable antenna can be made with 5 x 1/4 Lambda DV-27 27MHz CB antennas arranged as four ground plane elements and one in the centre as the driven element.  First seen (by myself) back in the early 80's when CB kicked off here in a big way.  Very simple - basically, there was a normal DV-27 mounted in the centre of a 12" square plate of aluminium, the corners of this plate were bent down some 45 degrees and another DV-27 bolted to each corner.  Not elegant but it certainly worked well enough and stood right on the ground and offered very little resistance to wind.  Just 4 nuts and bolts and a plug to assemble - took less than 5 minutes to assemble.  A DV-27 will tune to 28MHz if required Wink


Last edited by DragonForce on Sat May 17, 2014 1:56 am; edited 1 time in total (Reason for editing : A DV-27 is 1/4 lambda, not 3/8 - doh!)

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Re: The simplest QRP HF portable antenna?

Post by Admin on Fri May 16, 2014 6:11 pm

Ivan wrote:Hi all,
telescoping fishing poles are recommended as antenna supports quite often. The problem is that they tend to collapse when axially loaded. This is usually solved using a glue tape. Umbrella stands can hold them in place.

VBR from Ivan
Hi Ivan,
That's a great idea. Telescopic fishing poles! I shall look into that. Do you know "off-hand" the longest fishing rods are?

BR Harry

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Re: The simplest QRP HF portable antenna?

Post by Ivan on Fri May 16, 2014 6:18 am

Hi all,
telescoping fishing poles are recommended as antenna supports quite often. The problem is that they tend to collapse when axially loaded. This is usually solved using a glue tape. Umbrella stands can hold them in place.

VBR from Ivan

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The simplest QRP HF portable antenna?

Post by Admin on Thu May 15, 2014 6:09 pm

Hi all,
I wonder if anyone has any simple, cheap, quick and effective antenna support ideas? I hope shortly to operate in an area where there are few trees, but I do not want the hassle of trying to untangle wire out of antenna-eating trees. So I will give you a challenge: Describe or draw an antenna solution that can be deployed in minutes, is repeatable so tuning is stable, and can be used for 7MHz, 14MHz and/or 28MHz.


My first idea:
My own idea is to get three lengths of building timber, 2cm square, 4m long and place them side-by side. The the top and bottom I screw a metal plate to join poles 1 and 3 at both sides. At one end of the centre pole I fasten a metal plate/guide to keep the bottom between the two outer poles. The centre pole will will thus slide in and out in telescope fashion to extend from 4m to 7.5m.


Three of these telescoping poles should be adequate to support a thin 14MHz horisontal dipole at 8m AGL. The poles can be supported in garden umbrella stands, with a diagonal foot, about 2m to prevent the outer two poles falling inwards and give some stress to the wire.

The outer feet can be moved to accommodate any length of dipole and the centre pole supports a small balun. URM76 8m can be supported by the center pole. I prefer a horisontal 1/2-wave centre-fed antenna elevated at both ends because:
- no ground-plane needed
- not (less) affected by external influences

- generally more efficient
- better propagation for DX
- Can be moved to notch out QRM


The three poles can be retracted to 4m and put on the jeep roof-rack. I would guess the erection time would be about 10 minutes if properly prepared.

Any comments or better ideas? Very best regards from Harry - SM0VPO


PS - What do you call a Yorkshireman in a big posh house?

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