KU4AB 50MHz Loop for FD use?

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VK4GHZ
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KU4AB 50MHz Loop for FD use?

Post by VK4GHZ »

Hi all

Does anyone have any comments about the KU4AB 50MHz loop antenna?
I am considering getting one for field day use.

http://www.ku4ab.com/6m-horiz.html

From what I understand, as well as being cheaper than the M2 offering, they are more robust.

Can't be bothered with a yagi anymore, and frankly, they are not really necessary for Es work anyway.
The loop being horizontally polarised, omni directional, lightweight (1.4kg), compact, and not having to rotate, does have a lot of appeal for FD use.
Gain is specified at 2.7dBd, and you can easily stack a second (@ 12' ) for gain comparable to a 3-4 element yagi.
At US$73.95 + US$27.55 USPS shipping, it ain't going to break the bank either.

I know a VK2 has ordered one just recently... who?
(Yours got shipped yesterday, BTW)

Cheers,
Adam, VK4CP
Adam, Brisbane
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Re: KU4AB 50MHz Loop for FD use?

Post by VK3KH »

Adam,
I have used the following design Moxon on FD's for the last 18 months:
http://www.n2mh.net/moxon.htm
This antenna was the easiest antenna I have ever made. All the hardware items were easily obtained at Bunnings.
It is light and it never ceases to amaze me how well it works. I have even had several other stations reproduce it after seeing it in operation with the VK3XPD team station at Spring FD 2008.
It took 2 hours to make with hand tools.

Michael
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Re: KU4AB 50MHz Loop for FD use?

Post by VK4GHZ »

VK3KH wrote:Adam,
I have used the following design Moxon on FD's for the last 18 months:
http://www.n2mh.net/moxon.htm...
Michael, interesting.
What stops it collapsing into a parallelogram?

I was actually interested in the halo, because of the omni directional pattern.
When Es opens on 6M, signals can come from all over the place, and not having to rotate a directional antenna is a bonus.
Less chance of missing a QSO too, because the yagi was facing another way at the time.
Adam, Brisbane
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VK6ADF
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Re: KU4AB 50MHz Loop for FD use?

Post by VK6ADF »

VK4CP wrote: What stops it collapsing into a parallelogram?
Presumably the way its mounted and done up tightly. :wink:

Image


Have a look here

http://www.n2mh.net/moxon_ph.htm

73 Phil...VK6ADF
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Re: KU4AB 50MHz Loop for FD use?

Post by VK4APN »

VK4CP wrote:
VK3KH wrote:Adam,
I have used the following design Moxon on FD's for the last 18 months:
http://www.n2mh.net/moxon.htm...
Michael, interesting.
What stops it collapsing into a parallelogram?
I was actually interested in the halo, because of the omni directional pattern.
When Es opens on 6M, signals can come from all over the place, and not having to rotate a directional antenna is a bonus.
Less chance of missing a QSO too, because the yagi was facing another way at the time.
If the Moxon interests you and you dont want to build one check out
http://www.parelectronics.com/stress_moxon.htm
I have the arrl review on it and the ku4ab halo that I can email if you are interested.
Gain is quoted 5.8dbi so a step up from the halo. I have used halo antennas on 144mhz they do work.
Any joy with the 1296 loop antenna yet?
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Re: KU4AB 50MHz Loop for FD use?

Post by VK3KH »

Hi Adam, et al,
It stays in shape as Phil has suggested, due to tight assembly and the support. An interesting thing about the support is that I used plastic water pipe (approx 50mm diameter), cut into two pieces, and in the centre used a T piece with the open outlet facing down. This allowed me to take a 3 metre length of the same plastic pipe which when pushed up into the T piece beacame the support mast.
It is very light, and has proven very hardy, depite having been blown over on several occassions. This was due more to my poor anchoring than anything else.
I think the real delight of this antenna was how easy it was to make.

I guess the decision on whether to do omni or directional is a personal one.

Michael
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Re: KU4AB 50MHz Loop for FD use?

Post by VK4CZ »

Hey Adam

Halo in shed collecting dust ready for Winter VHF/UHF Field Day (5 element yagi from VK9WI also :wink: ) - was originally built as prototype for YJ8 beacon – remember we were trying for that back in 1998?

Antenna still assembled and ready for use! :D

http://picasaweb.google.com/Yarragib/Am ... 7740686258
Scott VK4CZ
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Re: KU4AB 50MHz Loop for FD use?

Post by VK3BJM »

C'mon Adam - think bigger - try knocking up a 6 m Big Wheel! :twisted: :lol:

73,
Barry
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Re: KU4AB 50MHz Loop for FD use?

Post by VK3PF »

Hi Adam,

Another option would be a pair of turnstiled single quad loops. LB Cebik described the antenna in the May 2002 issue of QST. I am sure that I have seen something described which was a collapsible version made from poly pipe & fittings that someone in the US was using for portable use - perhaps on the Cebik antenna site?

Only one issue - you need some 125 coax for the phasing line :(

I think I have a copy of the article at home - drop me a note and I will email it.

I am considering constructing one.....

However, I usually (when I can get out) use just a 2 m 5/8 whip... But I did build a square halo out of 19 mm al angle (3 mm think) and matched it with a gamma match. Real easy to build....

Peter VK3KAI
VK2GOM

Re: KU4AB 50MHz Loop for FD use?

Post by VK2GOM »

VK6ADF, we have an astronomer in our midst! That looks like a Meade equatorial wedge!

http://www.pbase.com/digitalphotons is my astro bit on the web.

BTW - PAR don't sell antennas that comprise metal elements outside of the USA. They will only sell the End Fedz etc. wire antennas. I've asked Dale Parfitt about this before when I was looking at their 6m omniloop.

73 - Rob VK2GOM
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Re: KU4AB 50MHz Loop for FD use?

Post by VK4GHZ »

vk4apn wrote:If the Moxon interests you and you dont want to build one check out
http://www.parelectronics.com/stress_moxon.htm
I have the arrl review on it and the ku4ab halo that I can email if you are interested.
Gain is quoted 5.8dbi so a step up from the halo...
After the crappy weather experienced during the recent Winter Field Day, I think it would be a safer bet to build a Moxon.
From what I have read, the narrow bandwidth loops can be thrown way out during rain.

I contacted PAR electronics, and they do not deliver outside of the USA. :cry:
(Funny how M2 can?!!!)
So, I am going to clone their stressed moxon design.
http://www.parelectronics.com/pdf/SM-50.pdf

Their design looks great... only tool required for assembly will be a screwdriver, as well as a shifter for the u-bolt.

(The Moxgen application I have attached below is available free for download from http://www.ac6la.com/moxgen.html.)

:D
Attachments

[The extension exe has been deactivated and can no longer be displayed.]

MoxGen ReadMe.txt
The associated Readme
(1.4 KiB) Downloaded 240 times
Adam, Brisbane
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VK4APN
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Re: KU4AB 50MHz Loop for FD use?

Post by VK4APN »

Great program - produces exact EZNEC files too. Thanks for posting it.
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