Curious Sunrise Fadeout Effect

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John Faulkner, Skegness
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Curious Sunrise Fadeout Effect

Post by John Faulkner, Skegness » 05 Jan 2017 13:09

This is a weird one. Does anybody know what causes this?

Sunrise is supposed to be one of the peak times for medium wave DX reception. Signals from the east fade out before those from the west, leaving less European interference to the transatlantic signals. Not here they don't. I have a block which lasts around one hour around sunrise, and this is almost nightly this winter.

Screen grabs.

https://app.box.com/s/wtzstlmph3bcpo3nmqonvnxcxln4q9fo
https://app.box.com/s/wjqbvpdjtm0n66cgg89p3ifaibp7posp

What on earth is happening?

simbeav
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Re: Curious Sunrise Fadeout Effect

Post by simbeav » 05 Jan 2017 21:10

Don't know what the reason is, but it's the same here.
I can leave for work just before 7 with NA blasting in and think there will be more and better to here on later recordings, but there is rarely much more than CHIN making it through, if that.
The sun seems to be constantly throwing things at us. I haven't a clue if that is the cause.

tvdxrools
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Re: Curious Sunrise Fadeout Effect

Post by tvdxrools » 06 Jan 2017 09:00

the sun has been playing up far too much in my opinion and looking back at some of my rec from previous years at this time i was getting good peaks at 1000 1100 and the band was open at midday at times but certainly not this season and the norm this season it seems the band is dropping out from 0830 - 0900 and tbh i am losing interest fast BUT there is not much else to listen to even 11/10m has been utter garbage but i had good fun the other day on 11m with the yagi beaming over the pacific and i was getting great back scatter sigs from southern uk with s9 signals at times , David

tvdxrools
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Re: Curious Sunrise Fadeout Effect

Post by tvdxrools » 06 Jan 2017 09:24

at 0900 this morning i stopped rec just before 0900 as hardly a TA sig there worth listening too , David

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John Faulkner, Skegness
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Re: Curious Sunrise Fadeout Effect

Post by John Faulkner, Skegness » 06 Jan 2017 13:05

Thanks Simon and David.

So you to have seen this effect in Jaguar YAS LOG. I don't get it. Sunrise gives us a peak. Not a fadeout.

I couldn't agree more David. You are rapidly LOSING interest? I have LOST interest. What is happening? The predictions are all over the place. The almost non-stop bombardment from the sun has surprised me. We should be getting better than this. I'm sure we will, but it looks like we'll have to wait one more season.

The fantastic Asiatic DX here in September and October suggested things would be MUCH better in midwinter.

There weren't any late fade-outs in Skye either. 0900 was the last usable toh.

My flag is playing up and I cannot be bothered to look at it in this bitterly cold weather. Noise levels are plaguing me too. They're not bad, but bad enough. The only things which are holding my interest in MW at the moment are the recent reports of Panama on 1350 and Lesotho on 891. It's a grab 'em while you can scenario, but I am not expecting miracles.

I'm just about done with MW this season.

Edit: One more grab from this morning. Same effect, but strange how a few frequencies are unaffected. The overall effect is clear.

https://app.box.com/s/sdpzc2wntvoq9wnuz6nwl3b530flxkm1

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John Faulkner, Skegness
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Re: Curious Sunrise Fadeout Effect

Post by John Faulkner, Skegness » 07 Jan 2017 12:24

I thought I ought to add something else to this. It's not just DX conditions. I noticed yesterday that even European signals suffer the same fade-out effect. I would love to know what causes this.

tvdxrools
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Re: Curious Sunrise Fadeout Effect

Post by tvdxrools » 07 Jan 2017 12:32

0730 0800 the usual east coast stuff were strong but the fade out started at 0830 and virtually nothing there at 0900 which is unreal for this time of year and i checked a rec from 2012 on this day and i had kjr komo cjob etc from 1000 onwards , David

Jim (Bournemouth)
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Re: Curious Sunrise Fadeout Effect

Post by Jim (Bournemouth) » 08 Jan 2017 09:28

There have been a lot of coronal holes on the Sun through this autumn and winter leading to geomagnetic disturbances - conditions often been poor.

I rum a monitor on 160m JT65 - if you go here ;
https://pskreporter.info/pskmap.html?pr ... hidepink=1#

you will see what has been coming in here over the past 3h. You can change the time range from the drop-down on the right.

The frequency is 1838khz, so should be quite representative of the upper part of the MW band.
Jim, Bournemouth, Dorset. IO90BR.

Elad FDM-S2, Perseus/FM+ and Funcube Dongle SDR Recievers 8-element OP-DES for Band 2, 12-ele ZL Special for 2m, plus wideband vertical
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Image

Rob J
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Re: Curious Sunrise Fadeout Effect

Post by Rob J » 08 Jan 2017 10:47

Thanks, Jim. I'll bookmark that and see how it shows conditions are in the late evening.

Had a quick look at 7am this morning and a fair bit of North American MW DX was coming in.
Rob.

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John Faulkner, Skegness
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Re: Curious Sunrise Fadeout Effect

Post by John Faulkner, Skegness » 08 Jan 2017 11:06

Thanks for this Jim.

I also forgot to elaborate on something else. If you haven't clicked on the links and seen this fade-out effect, it's not just a fade-out in itself, but a brief fade-out, then conditions come back up again. An unexplained temporary drop in activity, which affects European signals too.

I am going to write to QRZ and put this to them. Surely they will have noticed the same effect on top band.

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Re: Curious Sunrise Fadeout Effect

Post by John Faulkner, Skegness » 30 Nov 2017 12:04

SOLVED!

I now know what my pre-sunrise blackout periods are. I only realised this morning when I saw TWO of them. Both were due to bursts of noise. I usually get just one of these around the sunrise period, lasting between approximately 30 minutes to two hours. This morning's sunrise burst had split in two for some reason and both corresponded to my dawn fadeouts. I'll probably demonstrate this in a video at some point.

I will now reveal my middle names. I am John "get's there eventually!" Faulkner, well known for, er, getting there .... eventually! :D :lol:

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Re: Curious Sunrise Fadeout Effect

Post by daveB » 01 Dec 2017 12:07

But is the burst of noise "around sunrise" or is it that at this time of year sunrise happens to coincide with a burst of noise that occurs at a regular time during the morning?

Among other noise issues on FM, in the past I've experienced severe noise which I put down to a nearby factory turning on RF heating. It would suddenly appear at around 8 am local time and then after a period gradually fade out.

One of the reasons gave up HF Ham radio was that immediately after the 1987 storm, during a 4 hour power cut I could operate on battery power. 14 MHz was full of decent signals - then the power came back on and hardly any signals were left! It was the DX that was exciting not endlessly exchanging "u r 5 by 9, my name is Ivan, I'm running x watts to a y antenna - thank you for qso pls qsl 73's" with Russian/East Europeans - or indeed with /Spanish or Italian stations [substitute name as appropriate]..
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John Faulkner, Skegness
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Re: Curious Sunrise Fadeout Effect

Post by John Faulkner, Skegness » 01 Dec 2017 13:31

A good question Dave.

Unfortunately, it's as if the noise knows when I DX, cos it adjust itself according to the optimum conditions in the afternoon, for Asiatic DX, and in the morning, for sunrise DX. Of course, whatever it is simply follows some kind of auto-sensing for certain times of the day. It adjusts itself perfectly to kill off all peak DX times.

How's that for bad luck?

I know exactly what you mean regarding a quiet band Dave. Power cuts are annoying, but when listeners are able to DX at such times, they will be blown away when they hear what a truly quiet band sounds like. If you've never experienced the joys of DXing with a remotely situated Beverage, or somewhere in the wilds, miles from civilisation, then you just don't know what you are missing.

Ignorance is bliss!

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