Noise, Flags & K9AYs. Advice Needed.

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John Faulkner, Skegness
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Noise, Flags & K9AYs. Advice Needed.

Post by John Faulkner, Skegness » 18 Jan 2018 11:59

I have been wondering if it's worth me experimenting with another kind of antenna for medium wave. As you know, I can't sing enough praises about the flag antenna, but I am pulling my hair out regarding noise.

Yesterday, I moved my flag into different positions and different parts of the garden in a vain attempt to find the direction of my noise. It was not nullable in any direction! This might suggests that the noise could be coming from underground cables, though nothing I do points clearly to anything. The noise is simply everywhere! Perhaps somebody with more knowledge about DFing noise, etc. will be able to find the noise in seconds. I was also wondering if it was my flag is the problem as there's soemthing odd about the tuning of the resistor. But I was able to remove some of the noise yesterday by bypassing the tuning resistor. This somehow cuts the noise down by about 50%. UK/European splatter is immediately worse, but the noise is reduced.

It would also be good to secure an antenna and remove the chances of antennas blowing over in the high winds we get here. This has happened twice this week.

So, I was thinking about building a K9AY. On paper, it looks like the null is similar to that of the flag, plus I understand that it has more gain. Perhaps somebody can correct me if that is wrong. I am a disaster area when it comes to building antennas so I don't want anything too complicated. The only thing which worries me about the K9AY is its height. 25 feet for the central support is too high. I wonder if a K9AY would work if it was slightly reduced in size? I already had the housing officer visit last week asking what on earth 'that wire' was on my garden. (My flag!) She also asked if there was a wire running into the property, to which I answered "Yes". So I am expecting more trouble regarding this.

Any information, tips, advice, help, etc. would be appreciated. Or I am close to giving up medium wave DXing for good, unless my noise magically stops.

Thanks.

satnipper
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Re: Noise, Flags & K9AYs. Advice Needed.

Post by satnipper » 18 Jan 2018 15:15

I don't think swapping the Flag for a K9AY would help the noise issue. I also don't think underground cables are the culprit as the soil would grossly attenuate the noise. I may be wrong on both counts but on the balance of probabilities...

Where does the noise start and where does it end on the spectrum? Is the noise less in the HF amateur bands? If you replace the Flag with a simple long-wire or sloper is the noise the same? Can you post a sample video of the noise?

If the noise is causing reception on the amateur bands to be badly impacted as a licensed amateur you can raise a case with Ofcom directly. Worst cases are solar panels and/or VDSL - Ofcom will do nothing. Best case is a dodgy power supply which they can try and locate and speak to the owners...I heard about a case this week whereby a herb blanket (new to me as well) battery was pulsing all over HF...Swapping the cheap Chinese ps for a Slab cell cured the issue.

Good luck.

Stuart

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John Faulkner, Skegness
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Re: Noise, Flags & K9AYs. Advice Needed.

Post by John Faulkner, Skegness » 18 Jan 2018 15:49

Hello Stuart.

The noise starts at the bottom of medium wave from about 700 kHz. It's solid right up to 10 MHz. I haven't checked above 10 MHz. So amateur bands are affected. Perhaps I should reactivate some kind of amateur radio operation so I can state my case as a practising operator. Do you think that would helop my case is I reported this to OFCOM?

I posted a video of the noise some time ago. https://youtu.be/i2vOAq-YrM0

This noise peaks at certain times of the day too. The lengths of the stronger noise bursts vary, as does the duration, but there are three main daily bursts. Midday, late afternoon into early evening and sunrise.

This video demonstrates the main noise bursts. https://youtu.be/eBg7ndkfINw

There are properties with solar panels nearby but this noise is not coming from them.

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John Faulkner, Skegness
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Re: Noise, Flags & K9AYs. Advice Needed.

Post by John Faulkner, Skegness » 18 Jan 2018 15:57

Just done a quick update. Shocking! The noise overs the whole of HF and beyond!

Bear in mind the antenna I am using for this demo is a flag. https://youtu.be/nYnKl8qYkw8

satnipper
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Re: Noise, Flags & K9AYs. Advice Needed.

Post by satnipper » 18 Jan 2018 16:56

That seems to me to be a power supply type QRM. Not VDSL I think .

You HAVE to be an amateur to report directly to Ofcom. Get your 7000 set-up with a simple antenna and record the amateur bands. I'm not sure of Ofcom report link but think you can get to it from the RSGB EMC section.

Stuart

satnipper
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Re: Noise, Flags & K9AYs. Advice Needed.

Post by satnipper » 18 Jan 2018 17:21

Band II dxers prepare to have your hobby wiped-out

http://www.southgatearc.org/news/2018/j ... mDXeq5l-Ht

Nick Gilly
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Re: Noise, Flags & K9AYs. Advice Needed.

Post by Nick Gilly » 18 Jan 2018 20:20

Some more details here:

https://www.increasebroadbandspeed.co.u ... t-is-gfast

Seems that G.fast profile 1 will use 106 MHz, but in future profile 2 will use 212 MHz. That'll wipe out some people's DAB reception as well. Wasn't that supposed to be the main digital platform going forward?

Madness.
Good DX.

Nick, Whitchurch, Hampshire.

BW Broadcast RBRX Encore, Kenwood L-1000T, Yamaha T-2, Denon TU-800L, Kenwood KT-1100SD (modified), Yamaha T-85, Sony XDR-F1HD tuners, horizontal Körner 9.2 beam (Antennenland version), Yaesu G-450C rotator

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John Faulkner, Skegness
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Re: Noise, Flags & K9AYs. Advice Needed.

Post by John Faulkner, Skegness » 18 Jan 2018 23:43

You're right Stuart. Time to dust off the IC-7000.

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