Return-Path: Received: from rly-dd09.mx.aol.com (rly-dd09.mail.aol.com [172.19.141.156]) by air-dd06.mail.aol.com (v121_r4.4) with ESMTP id MAILINDD063-b994959f4f231f; Tue, 30 Dec 2008 05:16:29 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-dd09.mx.aol.com (v121_r4.4) with ESMTP id MAILRELAYINDD093-b994959f4f231f; Tue, 30 Dec 2008 05:16:21 -0500 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1LHbdE-0002iv-Vu for rs_out_1@blacksheep.org; Tue, 30 Dec 2008 10:15:24 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1LHbdE-0002im-CZ for rsgb_lf_group@blacksheep.org; Tue, 30 Dec 2008 10:15:24 +0000 Received: from mk-filter-1-a-1.mail.uk.tiscali.com ([212.74.100.52]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1LHbdD-0003lc-4L for rsgb_lf_group@blacksheep.org; Tue, 30 Dec 2008 10:15:24 +0000 X-Trace: 124835288/mk-filter-1.mail.uk.tiscali.com/B2C/$b2c-THROTTLED-DYNAMIC/b2c-CUSTOMER-DYNAMIC-IP/88.106.111.235/None/g4wgt@tiscali.co.uk X-SBRS: None X-RemoteIP: 88.106.111.235 X-IP-MAIL-FROM: g4wgt@tiscali.co.uk X-MUA: Microsoft Office Outlook 11Produced By Microsoft MimeOLE V6.00.2900.3350 X-IP-BHB: Once X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AsUWAAuDWUlYam/r/2dsb2JhbACCQi1UhVV4gyqvPViQOgaGPg X-IronPort-AV: E=Sophos;i="4.36,301,1228089600"; d="scan'208,217";a="124835288" Received: from 88-106-111-235.dynamic.dsl.as9105.com (HELO asus) ([88.106.111.235]) by smtp.tiscali.co.uk with ESMTP; 30 Dec 2008 10:15:15 +0000 From: "Gary - G4WGT" To: References: <005a01c968ff$2a99ee10$6401a8c0@asus> <20081230001119.6500@gmx.net> Date: Tue, 30 Dec 2008 10:15:15 -0000 Message-ID: <004201c96a67$829ca710$6401a8c0@asus> MIME-Version: 1.0 X-Mailer: Microsoft Office Outlook 11 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3350 In-Reply-To: Thread-Index: AclqRjShvRn8x7MoQSmwbD1DQM2y+wAIDasg X-Karma: 0: X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: RE: LF: 500KHz QSB Content-Type: multipart/alternative; boundary="----=_NextPart_000_0043_01C96A67.829CA710" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.6 required=5.0 tests=HTML_40_50, HTML_FONTCOLOR_UNKNOWN,HTML_MESSAGE autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-AOL-IP: 193.82.116.20 ------=_NextPart_000_0043_01C96A67.829CA710 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Laurence, Dennis, LF, =20 Good discussion has emerged since my first observation. I have had many constructive comments from various LF authors on here. =20 Laurence has stated just what I have been thinking to myself that it is only now with the introduction of the wideband Softrock SDR & the software (SpecLab) that it has come to my attention visually & caused me to question what I previously had overlooked or taken for granted. I believe I am more inquisitive now than my early days in the hobby. =20 Thank you Dennis & Laurence for your input. =20 73 =20 Gary =96 G4WGT. =20 _____ =20 From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Laurence BY3A-KL1X China Sent: 30 December 2008 06:14 To: rsgb_lf_group@blacksheep.org Subject: RE: LF: 500KHz QSB =20 This was a very good write up - thanks - =20 With the advent on "spectrum analyers" and panaraomic displays with the new SDR radios they provide a very telling visual fade pattern on even narrow FSK modes on HF - as you said you could actually visualize the antiphase moving up and down in freq and having the affect on each tone. =20 I dont know but 500 seems to have some of the worse fade characteristics, not too slow and not too fast - just plain difficult for the info rate for some modes (:-) Funny but I never remembered the fading as much when I was at sea on CW/MCW... =20 As Alan has pointed out the phase/antiphase cancellation on multiple iono paths can ruin hours worth of listening on 137kHz and relatively small changes in location (a few Kms) can show diverse signal reception levels on some nights. =20 Long haul pretty good at the moment - DCF39 some 45-50dBs above my neons and other restaurant Christmas tree flashers on peak - the normal about 15-20 min fade pattern. =20 Laurence BY3A-KL1X Tanggu OM89UA ps Scott VE7TIL made it here on 40m WSPR last night :-) on the probe =20 > Date: Tue, 30 Dec 2008 01:11:19 +0100 > From: Dennis.Hennig@gmx.de > To: rsgb_lf_group@blacksheep.org > Subject: Re: LF: 500KHz QSB >=20 >=20 > Hi Gary! >=20 > Yes fading seems to be very selective.=20 >=20 > Have you ever been listening to a distant AM radio station? Give it a try :) > There it is often audible, that a "fading notch" travels through one sideband down to lower modulation frequencies, then there is a moment of often terribly distorted audio due to the notched out carrier (the remaining sidebands "virtually much overmodulated"), then the "notch" goes further through the second sideband (if this also passes your filter). >=20 > The fading is fast on shortwave, where almost all the time different skywaves "are fighting each other" , medium fast on medium wave, and in the case of longwave transmitters sometimes very slow (may take minutes).=20 >=20 > Here in Berlin this longwave radio QSB appears very nicely at dusk to the 204km away "Polskie Radio I" 225kHz transmitter. The skywave becomes stronger and seems to equal the value of the groundwave, so constructive and destructive interference takes place. >=20 > Have a nice evening :) > Dennis=20 > DL6NVC >=20 >=20 > --=20 > Psssst! Schon vom neuen GMX MultiMessenger geh=F6rt? Der kann`s mit allen: http://www.gmx.net/de/go/multimessenger >=20 _____ =20 Life on your PC is safer, easier, and more enjoyable with Windows Vista=AE. See how =20 ------=_NextPart_000_0043_01C96A67.829CA710 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Laurenc= e, Dennis, LF,

&n= bsp;

Good discussion has emerged since my first observation. I have had many construct= ive comments from various LF authors on here.

&n= bsp;

Laurenc= e has stated just what I have been thinking to myself that it is only now with the introduction of the wideband Softrock SDR & the software (SpecLab) t= hat it has come to my attention visually & caused me to question what I prev= iously had overlooked or taken for granted. I believe I am more inquisitive now tha= n my early days in the hobby.

&n= bsp;

Thank you Dennis & Laurence for your input.

&n= bsp;

73=

&n= bsp;

Gary &#= 8211; G4WGT.

&n= bsp;

From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Laurence BY3A-KL= 1X China
Sent: 30 December 2008 06:14<= br> To: rsgb_lf_group@blacksheep.org
Subject: RE: LF: 500KHz QSB

 

This was a very=20= good write up - thanks -
 
With the advent on "spectrum analyers" and panaraomic displays wit= h the new SDR radios they provide a very telling visual fade pattern on even narrow FSK modes on HF - as you said you could actually visualize the antiph= ase moving up and down in freq and having the affect on each tone.
 
I dont know but 500 seems to have some of the worse fade characteristics, no= t too slow and not too fast - just plain difficult for the info rate for some modes (:-) Funny but I never remembered the fading as much when I was at sea= on CW/MCW...
 
As Alan has pointed out the phase/antiphase cancellation on multiple iono pa= ths can ruin hours worth of listening on 137kHz and relatively small changes in location (a few Kms) can show diverse signal reception levels on some nights= .
 
Long haul pretty good at the moment - DCF39 some 45-50dBs above my neons and other restaurant Christmas tree flashers on peak - the normal about 15-20 mi= n fade pattern.
 
Laurence BY3A-KL1X Tanggu OM89UA
ps  Scott VE7TIL made it here on 40m WSPR last night :-) on the probe  


> Date: Tue, 30 Dec 2008 01:11:19 +0100
> From: Dennis.Hennig@gmx.de
> To: rsgb_lf_group@blacksheep.org
> Subject: Re: LF: 500KHz QSB
>
>
> Hi Gary!
>
> Yes fading seems to be very selective.
>
> Have you ever been listening to a distant AM radio station? Give it a t= ry :)
> There it is often audible, that a "fading notch" travels thro= ugh one sideband down to lower modulation frequencies, then there is a moment of often terribly distorted audio due to the notched out carrier (the remaining sidebands "virtually much overmodulated"), then the "notch&qu= ot; goes further through the second sideband (if this also passes your filter).<= br> >
> The fading is fast on shortwave, where almost all the time different skywaves "are fighting each other" , medium fast on medium wave, a= nd in the case of longwave transmitters sometimes very slow (may take minutes).=
>
> Here in Berlin this longwave radio QSB appears very nicely at dusk to t= he 204km away "Polskie Radio I" 225kHz transmitter. The skywave becom= es stronger and seems to equal the value of the groundwave, so constructive and destructive interference takes place.
>
> Have a nice evening :)
> Dennis
> DL6NVC
>
>
> --
> Psssst! Schon vom neuen GMX MultiMessenger geh=F6rt? Der kann`s mit all= en: http://www.gmx.net/de/go/multimessenger
>

Life on your PC is safer, easier, and more enj= oyable with Windows Vista=AE. See how

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