Testin the band and my aerial

Summary:

Activity on 4 July

Testing the band and my aerial

MI0WWB (30CW367) 05 Jul 2023 07:10

Earlier this morning, using my K3S running 40 watts to my 40/80 trapped dipole I worked a German station who was portable doing POTA, to me is signal was 549, of course I just got a standard 599 back. Later I reverted to 5 watts and was spotted on by a German, Finish and Estonian stations, the strongest signal SNR was just 6.

I then made a simple mono band dipole for 30m using light wire, the type supplied by Sotabeams. When cut I got a SWR of 1.2. The feedline does not extend to my shack, so I reverted to the back utility room with the KX2. At 11:05 I called out on 10.116 and was spotted within minutes by five stations, their respective SNR from the strongest was 17, 12, 12, 7 and 4. I heard another station calling on the same frequency, OZ/DL2JRM and was able to work him. I gave a 449 but just got a standard 599 back and it was all over!

Then I tried 10 watts on 10.118 again within minutes I was spotted by seven stations, their respective SNR from the strongest were; 16, 14, 11, 6, 6, 5 and 5. Not massively different from my earlier 5 watts test.

In the early afternoon I usually have found the band to be quiet, however today I worked DK9DK/P who was operating from Pellworm, a small island that is part of the North Frisian Islands. I received a 579 RST suggesting that my new dipole is more efficient. I will look forward to see what happens tonight when the band seems to get better.

Early evening calling CQ for 30 minutes on 5 watts produce a QSO for a French station also running 5 watts, RST was 549 and I received 549. Will see what its like later in the evening.

This band certainly warms up in the evening, I worked the grey line on 5 watts and was well spotted on RBN with a couple of spots reading values in the 20s, and the top eight spots were all in double figures. I worked four stations during the evening hours, a Danish station I worked was running 200 watts, the maximum allowed on this band.

This completes my testing, a mono dipole is definitely best, but for my next test I will try a vertical aerial, but I will have to make it first. The map below records the evening activity.

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Will de mi0wwb

Last edited on 05 Jul 2023 07:11 by MI0WWB (30CW367) Show more

Re: Testing the band and my aerial

G4OJW 08 Jul 2023 12:22

Hi Will,

Replying to your post at http://30cw.wikidot.com/forum/t-16142817/ant-for-30m:end-fed-half-wave-efhw#post-6143798 I thought I'd reply here as it seems the right thread on the topic of your ANTs and experiments.

I'll share a few observations, and I'm by no means an expert, but as I understand it!

The better propagation into Europe around 11Z, I'd expect this, as the F2 layer has now strengthened from the sun. Early in the morning, you can still get propagation to the west where it has all but decayed, but overhead and to the east it will be worse as it has decayed more. After some hours of sunshine it is back strengthened and will refract higher angles again.

I would indeed expect your dipole to probably be better than the EFLW because it is resonant at 30m, whereas your EFLW is an EFHW at 40m and will be resonant on 20m etc, but not on 30m. So making it match so the radio sees 50 Ohms but perhaps it is then not efficient as would be an EFHW, so you'd likely be better off with a shorter one that is a resonant EFHW on 30m.

Also I'm not sure about your dipole from looking at the photos. I think there are two things that could be improved and would make things much better. One, it does need to go higher, whether or not you have to remove the beam, I'd stick some pole above that and raise it up as high as I could. If you can get it above 10m that'd be great. Also I think it would help for it to be straighter without a sharp angle in the middle, depending on its orientation which would be most useful more North-South than East-West so you can get Europe, North America and Asia.

If the issue is that you cannot fit it into your garden in a straight line, could you fit it in by bending the ends instead? Because it is the middle of the dipole that is important (and also with EFHW the same, the middle, not the ends) for radiation. The middle should be as high and straight as possible (for a lower take-off angle and a more uniform azimuth pattern), the ends really do not matter but the centre does very much.

So for example if you have only 10m room in a straight line from the tower (5m either side) as an example just 10m but the length is 15m, then you can bend 2.5m at each end straight down, or sideways and this would still be good as little to no radiation occurs at the ends of the dipole.

OM SI G0FOZ 30CW344 has I believe a full 40m long EFHW for 80m up 10m almost all the way, even with a bend in it, and that's going to be resonant on all bands up including 30m, and he does get excellent result with it. I think the additional 3m height, plus resonance, will help a lot.

On 40m such antennae for the same height are electrically lower, but, appear to perform better, because you can get so many inter-G contacts on 40m with NVIS, not so on 30m where skip will be longer, NVIS less frequent, and also there's less activity.

Last edited on 08 Jul 2023 12:23 by G4OJW Show more

Re: Testing the band and my aerial

MI0WWB (30CW367) 08 Jul 2023 14:31

Thanks Al, yes I do have room, I can just squeeze in a 40/80 trapped dipole. I need to have a long think and work on my DIY skills, which are limited. Thanks for all the advice, this forum is a good reference point to visit.

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Will de mi0wwb

Re: Testing the band and my aerial

G4OJW 08 Jul 2023 16:14

You're not the only one :-) my DIY skills are very limited, my XYL is far better at DIY!

I got thinking about the RBN reports, as far as I understand it, I think the SNR dB given are how much signal is above the noise level, which obviously can vary substantially from RBN location to location. If that is the case, then we can't necessarily use the reports as actual signal strength, but they're still a good indication of getting out and offer a good degree of comparison over time.

WSPR is also very effective but needs a WSPR TX that is stable and accurate clock. I have used the QCX successfully for that in the past but also failed with a QCX Mini.

Re: Testing the band and my aerial

MI0WWB (30CW367) 08 Jul 2023 16:20

Ha ha my XYL is exactly the same, would not see me in her way! Your link to HFKits is excellent, some good instructional videos that even I can follow. You have got me hooked.

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Will de mi0wwb

Re: Testing the band and my aerial

G4OJW 08 Jul 2023 16:39

Exactly the same! She grew up following her father everywhere who was fantastic at DIY, even building houses, deep wells… so I'm in the way when she is fixing things, you know it :)

So I surprised myself building several QCX and QCX Mini, every time with success, although I blew most of them up later (broken ANT high SWR, static from a storm, high voltage 19V DC). The key was the impeccable step by step instructions that even I could follow!

The same with making a 49:1 UNUN. I always felt this was a difficult thing, and I used the QSL.net NF4RC PDF out of that list of links because I had a FT114-43 Toroid, and the windings are different. I even did it a little different, putting both a BNC and an SO-239 connecter on it. And it works great and looks great, I really surprised myself even though it took me days to build and now would probably take me an hour or two next time around.

What is funny is that I actually put the connections in the wrong way around plus I also bypassed the entire thing placing an extra wire in the wrong place, but realized it and fixed it myself without external help!

If you make an UNUN yourself though I'd recommend using a larger toroid as the FT114 is small and can only handle max about 35W CW. Or use more than one toroid on top of each other. I plan to buy larger ones and make more, and also to start making chokes (line isolators) as I have so many wires picking up RF. So I collected lots of information and links and glad it is helpful.

I've always liked making dipoles and doublets, but have always gone about things (except when I made commercial antennas at one stage, then I did things more professionally) in a "temporary" fashion and they always end up being not temporary, as you also alluded to in your recent post :-) then later I always regret not taking more effort the first time, e.g. with a proper centre piece rather than just twisting wires together that aren't protected.

I'll even start using baluns, chokes, and earth where appropriate, at least that's my intention, I think in large part helped by the fact of age and that whatever I put up is better to last rather than needing frequent repairs!

Last edited on 08 Jul 2023 16:41 by G4OJW Show more

Re: Testing the band and my aerial

MI0WWB (30CW367) 08 Jul 2023 17:42

I even went to our local hardware shop to buy a step drill to make the large opening for the bulkhead 259 socket, and I even used it correctly ;-).

Earlier today I had a QSO with an English station, so the skip must have been shorter than usual. It was funny, after the first over he keyed SRI and disappeared. He came back ten minutes later to my CQ call and said he had to take a phone call!

The signals were quite good in both directions.

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Will de mi0wwb

Re: Testing the band and my aerial

G4OJW 08 Jul 2023 18:28

There's also QRMX — see my list of abbreviations at https://qrz.com/db/g4ojw :-)

Re: Testing the band and my aerial

MI0WWB (30CW367) 08 Jul 2023 20:43

Ha ha, that’s a new one on me. How many know what it means, I didn’t, had to look it up.

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Will de mi0wwb