Re: LF: Re: Re: Re: Re: RE: Noise level low at 8270 :-)

["Alan Melia" <alan.melia@btinternet.com>]



Hi Markus yes I agree in this case it is unlikely to be much of a propagation effect around Europe. As I said the severity of the event was quite low. However lighning static can be propagated from a very great distance over multiple hops so a small amount of absorbtion due to electron precipitation could reduce say Southern Hemisphere static a lot. Laurence's VLF grabber does indicate attenuation of Mil signals at extreme range during geomag events. This would perhaps explain why short range signals suffer less. It might not mean that extreme propagation is better but lower local noise might compensate. It could be a case of comparing signals with noise from radically different ranges. The proper understanding and discussion like this might help to make best use of of the effect. :-))

 

Best Wishes

Alan 

----- Original Message -----

From: Markus Vester

To: rsgb_lf_group@blacksheep.org

Sent: Tuesday, February 18, 2014 1:11 PM

Subject: Re: LF: Re: Re: Re: Re: RE: Noise level low at 8270 :-)

Hi Alan, Peter,

 

I doubt that there is such a thing as "generally weak propagation" on these low frequencies, at least probably not for intra-European ranges. Of course we do see modulations of ionospheric ceiling height during SID's. But opposed to LF and MF, increased D-layer ionisation will probably not have the effect of an absorber beneath the reflecting E-layer. Looking at the grabbers, Russian Alpha and MSK signals appear no weaker than at other times. So the most likely cause for low background noise would be favourable weather with less lightning activity around Europe.

 

Best 73,

Markus (DF6NM)

 

-----Ursprüngliche Mitteilung-----
Von: Alan Melia <alan.melia@btinternet.com>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Mo, 17 Feb 2014 9:42 pm
Betreff: LF: Re: Re: Re: Re: RE: Noise level low at 8270 :-)

Hi Peter it might be that simple, or it might be a very complicated mixture :-)) yes static should be low at the moment (I havent looked at the Eu lighning charts) I could also be that your local car-repairer is off work with 'flu, though this event is obviously far wider than just local conditions, now we have a wider range of grabbers to sample for conditions. It is interesting because I would not expect the current geomagnetic conditions to have made that much difference......but it is interesting to ask the questions :-)) The only solution is try it and see if it IS better.

 

Good Luck

Alan

G3NYK

----- Original Message -----

From: PA1SDB, Peter

To: rsgb_lf_group@blacksheep.org

Sent: Monday, February 17, 2014 7:31 PM

Subject: LF: Re: Re: Re: RE: Noise level low at 8270 :-)

Hello Alan,

Tnx for info !

It is so simple, but I did not thought about this. I thought it has more to do with low lightning levels or static's.

It is still difficult for me to connect a link between audio frequency's and propagation...

 

73's, Peter.

 

----- Original Message -----

From: Alan Melia

To: rsgb_lf_group@blacksheep.org

Sent: Monday, February 17, 2014 6:54 PM

Subject: LF: Re: Re: RE: Noise level low at 8270 :-)

You need to be careful in what you interpret from this! the noise may be low because the propagation is rubbish :-))  The conditions dont necessarily support this but we have just had a minor storm Kp=5 and the Dst was depressed to -60nT.

 

I remember early on, on 136kHz when we thought that the best time for DX would be around dawn.......except it turned out that the morning and evening quiet periods were poor propagation periods as well.  You need a signal to determine S/N :-)) particularly if N is changing.

 

Alan

G3NYK

 

 

  

----- Original Message -----

From: PA1SDB, Peter

To: rsgb_lf_group@blacksheep.org

Sent: Monday, February 17, 2014 6:19 PM

Subject: LF: Re: RE: Noise level low at 8270 :-)

Hello Bob,

Interesting to see that the low noise today is at least "Europe wide" :-)

Perhaps even Worldwide ???

 

I wonder if you publish your spectogram's online somewhere ?

I think I did not see you in a 'grabber' list somewhere...

 

Unfortunately I don't see anything right now at 8270.014 in your spectogram.

I think to early to see first spikes :-)

 

First sign here today was at 16:20 UTC.

 

73's, Peter - PA1SDB

 

www.qsl.net/pa1sdb

 

 

 

 

----- Original Message -----

From: Bohuslav Coufal

To: 'rsgb_lf_group@blacksheep.org'

Sent: Monday, February 17, 2014 3:47 PM

Subject: LF: RE: Noise level low at 8270 :-)

Me too https://www.dropbox.com/s/c4wx1dukmctmhxh/Mereni-8270-last.bmp

 

73,

 

Bob., OK2BUM

 

From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of PA1SDB, Peter
Sent: Monday, February 17, 2014 4:40 PM
To: rsgb_lf_group@blacksheep.org
Subject: LF: Noise level low at 8270 :-)

 

Hi !

 

Low noise at http://www.ok2bvg.cz/vlfgrabber/ !

 

Btw, here to :-)

 

73's, Peter - PA1SDB

 

www.qsl.net/pa1sdb