23cm Yagi recommendations - please
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I have been using a 45 element / 3.6m boom G3JVL Q loop for a long time. Corrosion has finally taken hold and I am looking for a replacement.
I am looking for recommendations of commercially made (and available in Britain) of a directional antenna with a gain greater than 18dBd for my coastal location. Thanks Andy GD1MIP |
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geoffrey pike
Hi Andy, If you anyway handy with a few tools a DL6WU is the easiest thing to make. Some years ago i used 4x26 ele DL6WU and they performed really well even though i made the stacking frame distances wrong! cheers Geoff GI0GDP
On Sunday, 4 December 2022 at 18:57:23 GMT, Andy GD1MIP <gd1mip@...> wrote:
I have been using a 45 element / 3.6m boom G3JVL Q loop for a long time. Corrosion has finally taken hold and I am looking for a replacement. I am looking for recommendations of commercially made (and available in Britain) of a directional antenna with a gain greater than 18dBd for my coastal location. Thanks Andy GD1MIP |
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Thanks Geoff. Unfortunately I am snowed under with work meaning I want to buy a ready made antenna or it will never happen.
Andy GD1MIP |
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SAM JEWELL
Andy,
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I bought one of Goran's 43 element 23cm yagis back in the spring. It is the heavy duty (HD) one rather than the slightly lighter 43 element. My QTH is probably not as exposed as yours, although I am just a few miles from the east coast (don't I know it today!) and get some very high winds. The Antennas Amplifier yagi is well built and certainly seems to give the expected gain performance (compared to my other 23cm antennas). The match at 1296MHz is excellent. I bought the yagi from Nevada radio. I have no commercial ties with Goran or Nevada, i'm just a pleased customer. 73 de Sam, G4DDK Sent tomorrow from my iPad 10 On 5 Dec 2022, at 10:52, Andy GD1MIP <gd1mip@...> wrote:
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David Hilton-Jones
I’d sent a pm to Andy with exactly the same info, except that I got mine via Waters and Stanton. Very happy with it
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On Monday, December 5, 2022, 11:36 am, SAM JEWELL via groups.io <jewell@...> wrote:
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SAM JEWELL
Never quite sure of the current relationship between Nevada and W&S. One of their staff told me they share a warehouse. I have dealt with 'both' companies in recent years and have nothing but praise for their customer service.
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Sam, G4DDK Sent tomorrow from my iPad 10 On 5 Dec 2022, at 13:54, David Hilton-Jones via groups.io <g4ytl@...> wrote:
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Hi Andy, take a FLEXAYAGI 48 el. Performance with 18.5 dBi is super 73 de Ferdinand DC8EC
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g4cch_1
Worked BH1TSU off the Moon on 23cm, he has an Antennas Amplifiers 36 el yagi and 300W. Xiaxin went on to work KB2SA with a 1.9m dish and 800W, afyer several attempts.
Based on this, it looks like Goran's yagi's work very well... Howard, G4CCH |
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Rick Beatty
Andy -- Take a look at the 23cm antennas at "antennas and amplifiers.com" I have a pair of the 18 element back mounted antennas and they work quite well. Good Luck with the hunt -- Rick W7RNB On Mon, Dec 5, 2022 at 2:52 AM Andy GD1MIP <gd1mip@...> wrote: Thanks Geoff. Unfortunately I am snowed under with work meaning I want to buy a ready made antenna or it will never happen. |
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Hi Andy,
I see everyone suggesting Antennas Amplifiers aerials. I bought the high power 70 element for 23cm. The elements started to corrode within a few weeks and the brackets are also rusting away nicely. Its been used twice portable I think and stored down the side of the house, it's never actually been up in the weather. I think I've seen that they have improved the material selection since, but I'll not go near them again. I'm currently using 2nd hand Tonnas and am very happy, the standoffs do go brittle and snap if hit, but they are fixed with a bit of super glue. But you can often pick up and old Tonna for spares or get a mate with a 3D printer to run one off for you. Nick G0HIK |
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Hi Andy I've used Tonnas for many years 4 x 4 x 23 ele in contest and more recently a 55 ele Tonna . They do suffer from broken plastic supports from time to time but are durable overall (I carry spares). The alloy can suffer from corrosion if not protected with a coat of external lacquer or varnish. I went over to a 67 ele Wimo 15 years ago and it's been fine , the 67 ele will handle full legal , Hope that helps 73 Bernie G4HWA On Sun, Dec 4, 2022 at 6:57 PM Andy GD1MIP <gd1mip@...> wrote: I have been using a 45 element / 3.6m boom G3JVL Q loop for a long time. Corrosion has finally taken hold and I am looking for a replacement. |
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Dave smith
Somewhere I have read that 3D printed insulators for the tona antennas are not a good idea in a wet environment as they can absorb water…..second hand opinion but may be worth consideration. Dave.. G4DAX On Mon, 5 Dec 2022 at 18:36, Bernieg4hwa <bernieg4hwa@...> wrote:
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I can recommend the IOJXX antennas that John G4ZTR is the UK distributor for
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Yep, got one of these 70 ele monsters Nick! Whilst the elements are not corroding, the support brackets are just starting to on the edges. The support brackets are ferrous metal alloy of some sort, mine will be getting a coat of hammerite in the summer. Other than the minor corrosion it allows me to actually work some stuff from a really poor VHF QTH without the need for stacking other beams. Incredibly well engineered piece of kit IMHO.
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MrBritdog
I recommend IOJXX 36 ele Andy for 23cm
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Thanks everyone for your help.
As I said I'd prefer to buy, not build. A decision made due to time constraints rather than skill, having built a few before. I live 20 yards from the sea, so corrosion and strength are my main concerns. Ideally I'd have a dish, but it'd be in Cumbria within weeks. My concerns re the Flexa metal clip mounted elements and IOJXX through boom mounted elements are corrosion where the metals join. I like the Antennas Amplifiers types, I have a VHF one, but as others stated corrosion again seems to be an issue. I have enough 'boom' material, Powabeam Paraclips and 5mm element materia and the glue together DE for 16mm tube. Has anyone used that DE at such high frequency? Thanks Andy GD1MIP |
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Robin Szemeti - G1YFG
Before you go too far ... I have so far been unsuccessful in establishing good boom correction figures at 23cm to get a resonant antenna. My view is that it is non-trivial to get good results without accurate boom correction. At 70cm, I was out by 0.6mm and it has a devastating affect on performance, correcting that error resulted in a very good antenna. My error had been to use 20mm box section instead of 3/4" (19mm) which threw it all out. At 23cm I have spent "some time" construction wooden reference antennas and numerous metal versions with isolated elements and attempted to establish boom correction figures that would make the metal boom versions element lengths identical to the wooden variant ... so far I have failed. I would suggest that unless you have a known design, that works with the particular type of clip on the particular dimension of boom and the same element diameter, to consider carefully before making your own. On Tue, 6 Dec 2022 at 16:39, Andy GD1MIP <gd1mip@...> wrote: Thanks everyone for your help. --
Robin Szemeti - G1YFG |
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John Lemay
Robin
Boom correction seems to be as much an art as it is a science ! If you haven’t looked already, DG7YBN has done a lot of experiments too. A problem with wooden booms, even kiln dried timber, is that it can still contain 20% moisture. That’s before you get it outside.
Andy
Using the Powabeam dipole box will result in most of the dipole being inside the box. It just doesn’t feel right. In addition the dipole would be extremely fat, probably taking it outside the range of length/thickness for which modelling is valid. I’ve used the Paraclips with 5mm parasitic elements on 23cms and that part does work as expected.
John G4ZTR
From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Robin Szemeti - G1YFG via groups.io
Before you go too far ... I have so far been unsuccessful in establishing good boom correction figures at 23cm to get a resonant antenna. My view is that it is non-trivial to get good results without accurate boom correction.
At 70cm, I was out by 0.6mm and it has a devastating affect on performance, correcting that error resulted in a very good antenna. My error had been to use 20mm box section instead of 3/4" (19mm) which threw it all out.
At 23cm I have spent "some time" construction wooden reference antennas and numerous metal versions with isolated elements and attempted to establish boom correction figures that would make the metal boom versions element lengths identical to the wooden variant ... so far I have failed. I would suggest that unless you have a known design, that works with the particular type of clip on the particular dimension of boom and the same element diameter, to consider carefully before making your own.
On Tue, 6 Dec 2022 at 16:39, Andy GD1MIP <gd1mip@...> wrote:
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I seem to recall from discussions with various hams that several of the currently available commercial 23cms antennas are based on the old DL6WU design.
If any are considering building antennas for 23cms this info may be of use -
This is linked from Ian G(M)3SEK’s Long Yagi Workshop pages.
Hoping this info may help, even if somewhat dated.
73
Bob, G1ZJP
On 6 Dec 2022, at 16:48, Robin Szemeti - G1YFG via groups.io <robin@...> wrote:
Before you go too far ... I have so far been unsuccessful in establishing good boom correction figures at 23cm to get a resonant antenna. My view is that it is non-trivial to get good results without accurate boom correction.
At 70cm, I was out by 0.6mm and it has a devastating affect on performance, correcting that error resulted in a very good antenna. My error had been to use 20mm box section instead of 3/4" (19mm) which threw it all out.
At 23cm I have spent "some time" construction wooden reference antennas and numerous metal versions with isolated elements and attempted to establish boom correction figures that would make the metal boom versions element lengths identical to the wooden
variant ... so far I have failed. I would suggest that unless you have a known design, that works with the particular type of clip on the particular dimension of boom and the same element diameter, to consider carefully before making your own.
On Tue, 6 Dec 2022 at 16:39, Andy GD1MIP <gd1mip@...> wrote:
Thanks everyone for your help. -- Robin Szemeti - G1YFG |
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Robin Szemeti - G1YFG
Hi John, I have had plenty of emails with Hartmut YBN :) ... I made plenty of experiments, using software to translate the output of my excel files into lengths the CNC mill could cut from 4mm rod. I also have a set of brass elements made from 4mm tube over 3mm tube so the length can be adjusted. I shall have to do more on this over the winter, On Tue, 6 Dec 2022 at 17:12, John Lemay <john@...> wrote:
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Robin Szemeti - G1YFG |
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