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Homebrew Equipment A place to show, design and discuss the weird and wonderful electronic creations from the hands of individual members. |
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14th Jun 2021, 3:35 pm | #1 |
Octode
Join Date: Jun 2013
Location: Huddersfield, West Yorkshire, UK.
Posts: 1,795
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2 metre Yagi antenna
Hi peeps.
Searched high and low on "Tinternet" for a reliable design for a 2 metre 4 ele yagi with folded loop dipole. I thought I had seen one at one time or another.... but it is eluding me..has anyone got a link for Dimensions & a reliable easy to make matching element for 50 ohm coax. Thanks
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Should get out more. Regards Wendy G8BZY |
14th Jun 2021, 4:32 pm | #2 |
Guest
Posts: n/a
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Re: 2 metre Yagi antenna
A quick look about and... http://radio.meteor.free.fr/us/antenna.html you could simulate it in something like MMANA-GAL before going to metal.
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14th Jun 2021, 4:36 pm | #3 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,007
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Re: 2 metre Yagi antenna
Do a search for 'NBS Technical Note #688' which documents extensive testing and modeling done by Peter Viezbicke on behalf of the US National Bureau for Standards in the mid-1970s.
There are plenty of 'ham band' designs based on this analysis. |
14th Jun 2021, 4:38 pm | #4 |
Guest
Posts: n/a
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Re: 2 metre Yagi antenna
And, a Nano-VNA is an almost must for aerial fiddling, next day for 40 quid, half as much for a bit of a wait.
https://www.amazon.co.uk/Analyzer-50...685025&sr=8-10 |
14th Jun 2021, 11:03 pm | #5 |
Octode
Join Date: Jun 2013
Location: Huddersfield, West Yorkshire, UK.
Posts: 1,795
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Re: 2 metre Yagi antenna
Hi Merlin. Got one had it a while
Thanks peeps.... I have an ex FM ant to cut down..
__________________
Should get out more. Regards Wendy G8BZY |
14th Jun 2021, 11:20 pm | #6 |
Octode
Join Date: Jul 2018
Location: Worthing, West Sussex, UK.
Posts: 1,003
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Re: 2 metre Yagi antenna
Don't cut too much off Wendy- it is a one way street
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15th Jun 2021, 2:38 am | #7 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,902
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Re: 2 metre Yagi antenna
Oh, I dunno. I've TIGged bits on aerials for a few people. But cutting is definitely easier and cheaper.
David
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Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
15th Jun 2021, 3:33 am | #8 |
Nonode
Join Date: Oct 2010
Location: Tintinara, South Australia, Australia
Posts: 2,343
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Re: 2 metre Yagi antenna
You'll have to adjust the spacing between elements as well as shortening them to get it to "work just right"
Here's one design https://vk3arr.wordpress.com/2016/07...ement-2m-yagi/ |
15th Jun 2021, 5:14 am | #9 |
Triode
Join Date: Oct 2008
Location: Perth, Western Australia, Australia
Posts: 40
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Re: 2 metre Yagi antenna
Hi Terry
Can thoroughly recommend Justins designs https://www.g0ksc.co.uk/2013-yagis/1...a/5el-lfa.html All the AL can be obtained from Bunnings and the stauff clamps from hydraulic/mining suppliers in most state capitals. I'm using his designs for 6m and 2m. I have a 7 el LFA for 2m and have worked into Melbourne on digital modes and SSB to Hamilton in VK3 (all > 2,700km). From a backyard of an inner suburban Perth QTH. Matching is almost perfect and its easy to build the ferrite choke "balun".
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Best Regards Nigel VK6CPU Perth, Western Australia |
15th Jun 2021, 6:06 am | #10 |
Nonode
Join Date: Oct 2010
Location: Tintinara, South Australia, Australia
Posts: 2,343
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Re: 2 metre Yagi antenna
Thanks Nigel.
All I need now are a new collapsible tower to put them on and something decent to put on the other end |
15th Jun 2021, 5:02 pm | #11 | |
Heptode
Join Date: Mar 2008
Location: Newmarket, Suffolk, UK.
Posts: 613
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Re: 2 metre Yagi antenna
Quote:
http://www.yu7ef.com/ Fred |
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16th Jun 2021, 11:38 pm | #12 |
Dekatron
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 4,935
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Re: 2 metre Yagi antenna
What's going on in W.Yorks on 2m now Wendy? I recall the late 60's early 70's when there were loads of people on AM, often Pye boxes, and J Beam '6 over 6' antennas were the must haves! Leeds had at least two ham radio clubs and there were two rallies there each summer.
Where I am now, I cannot hear anything at all; little activity and bad location (edge of a valley). B
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Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch. |
18th Jun 2021, 5:08 pm | #13 |
Octode
Join Date: Jun 2013
Location: Huddersfield, West Yorkshire, UK.
Posts: 1,795
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Re: 2 metre Yagi antenna
Hi Bazz. I originally started life in the market town of Otley, on the north side of the river with a J Beam 8 ele and 15 W AM. Not much good apart from Leeds, etc as the big hill to the south was a great "stopper". I was a founder member of Otley Radio soc, and eventually ran the NMR "Northern Mobile Rally" for two years,....it has had many different organisations run it since. In my view the Liner2. killed it for me, as everyone and his auntie went SSB. I am now in Huddersfield, with a 5 ele Moonraker.... just to put me on... and I will build a 2M SSB transceiver.... for the NEXT SPE season.
__________________
Should get out more. Regards Wendy G8BZY |
18th Jun 2021, 5:13 pm | #14 | |
Guest
Posts: n/a
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Re: 2 metre Yagi antenna
Quote:
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4th Jul 2021, 10:19 am | #15 |
Hexode
Join Date: Dec 2018
Location: Lugo, Spain
Posts: 483
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Re: 2 metre Yagi antenna
Where can i look at up to date predictions / conditions for sporadic E and tropo for vhf please .
I have tried DX maps are there any others ?. I am trying to get up on 2mts for ssb. |
5th Jul 2021, 10:32 am | #16 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,586
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Re: 2 metre Yagi antenna
For tropo, try the "Hepburn Tropo forecast". Our locked down works IT won't let me go there to get a link for you (thinks it is something to do with watching TV!). A google search for 'Hepburn Tropo' should find it.
On the landing page there is an easily missed small dropdown box, upper left, to select the region you want look at. |
5th Jul 2021, 4:15 pm | #17 |
Guest
Posts: n/a
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Re: 2 metre Yagi antenna
Here it is... https://www.rfcafe.com/miscellany/ho...-Forecasts.htm
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5th Jul 2021, 7:52 pm | #18 |
Heptode
Join Date: Sep 2004
Location: Preston, Lancashire, UK.
Posts: 632
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Re: 2 metre Yagi antenna
Hi Wendy. The DK7ZB designs are reliable and repeatable and lend themselves to repurposing other antennas. I made a 5 element from a moonraker 2m yagi that had an awfully implemented gamma match. Used 75 ohm ct100 for the matching transformer
Designs here https://www.qsl.net/dk7zb/start1.htm You could probably use what you cut off the loop driven element to make another parasitic element. Can also recommend the lfa designs. Ive a 7 element on the main mast |
7th Jul 2021, 8:01 am | #19 |
Hexode
Join Date: Dec 2018
Location: Lugo, Spain
Posts: 483
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Re: 2 metre Yagi antenna
Thank you for the Tropo pages.
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