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[195.171.43.25]) by mx.google.com with ESMTP id n7si16138981wjy.111.2014.05.21.05.58.14 for ; Wed, 21 May 2014 05:58:15 -0700 (PDT) Received-SPF: none (google.com: owner-rsgb_lf_group@blacksheep.org does not designate permitted sender hosts) client-ip=195.171.43.25; Authentication-Results: mx.google.com; spf=neutral (google.com: owner-rsgb_lf_group@blacksheep.org does not designate permitted sender hosts) smtp.mail=owner-rsgb_lf_group@blacksheep.org; dkim=pass (test mode) header.i=@btinternet.com Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Wn5k2-0000vq-Rz for rs_out_1@blacksheep.org; Wed, 21 May 2014 13:35:30 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Wn5k2-0000vh-0T for rsgb_lf_group@blacksheep.org; Wed, 21 May 2014 13:35:30 +0100 Received: from smtpout17.bt.lon5.cpcloud.co.uk ([65.20.0.137]) by relay1.thorcom.net with esmtp (Exim 4.82) (envelope-from ) id 1Wn5k0-00016Q-2l for rsgb_lf_group@blacksheep.org; Wed, 21 May 2014 13:35:28 +0100 X-CTCH-RefID: str=0001.0A090206.537C9D8D.004C,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0 X-Junkmail-Premium-Raw: score=13/97,refid=2.7.2:2014.5.19.53621:17:13.296,ip=,rules=__HAS_MSGID, __SANE_MSGID, MSGID_32HEX_LC, INVALID_MSGID_NO_FQDN, __MSGID_32HEX, __HAS_FROM, __PHISH_FROM2, __FRAUD_WEBMAIL_FROM, __TO_MALFORMED_2, __TO_NO_NAME, __BOUNCE_CHALLENGE_SUBJ, __BOUNCE_NDR_SUBJ_EXEMPT, __MIME_VERSION, __CT, __CTYPE_MULTIPART_ALT, __CTYPE_HAS_BOUNDARY, __CTYPE_MULTIPART, __HAS_X_PRIORITY, __HAS_MSMAIL_PRI, __HAS_X_MAILER, USER_AGENT_OE, __OUTLOOK_MUA_1, __USER_AGENT_MS_GENERIC, __ANY_URI, __FRAUD_BODY_WEBMAIL, __URI_NO_WWW, __URI_NO_PATH, __C230066_P5, __FRAUD_MISC, __SUBJ_ALPHA_NEGATE, SUPERLONG_LINE, __HAS_HTML, HTML_NO_HTTP, BODYTEXTP_SIZE_3000_LESS, BODYTEXTH_SIZE_10000_LESS, __MIME_HTML, __TAG_EXISTS_HTML, __URI_NS, HTML_50_70, __PHISH_FROM, __OUTLOOK_MUA, __FRAUD_WEBMAIL, FORGED_MUA_OUTLOOK X-CTCH-Spam: Unknown Received: from gnat (86.149.131.67) by smtpout17.bt.lon5.cpcloud.co.uk (8.6.100.99.10223) (authenticated as alan.melia@btinternet.com) id 536B69E600D894CA for rsgb_lf_group@blacksheep.org; Wed, 21 May 2014 13:35:12 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=btinternet.com; s=btcpcloud; t=1400675715; bh=MyNbJvegkw5zf9HduXdZ8esD1GMsUmiJYmgd6gDie0k=; h=Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Mailer; b=SHL7Lvm2xeZaTt7STMyjWyq9fXAqg9kTAnC5KwOKlGk4vKjBCOB2rfXTL1xnJrMzndKAb7I36wH+CUFW8exnHoH2ZkGpcpmMZtBp+AfLTvl/ApS7FCNxCNW6vu/QDtJWWG0N2IKk4quxSYMatcz9n9gyXIhFJdfMgOgH+86VGkU= Message-ID: From: "Alan Melia" To: References: <537B3F53.1000301@gmail.com> <537BF4D3.6050903@gmail.com> Date: Wed, 21 May 2014 12:41:30 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Hi Stefan, The way I try to separate ground and skywave is to look at a beacon transmission during daylight hours. the groundwave strength seems to correlate quite well with the minimum in the morning and evening dips. I find tis gives similar values to those calculated by the late G3FGQ's GRNDWAV3. [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [65.20.0.137 listed in list.dnswl.org] 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 310131a5e532565f108a820138314750 Subject: Re: LF: Re: MF propagation Content-Type: multipart/alternative; boundary="----=_NextPart_000_0012_01CF74F1.FD6E5340" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: ** X-Spam-Status: No, hits=2.5 required=5.0 tests=FORGED_MUA_OUTLOOK,HTML_30_40, HTML_MESSAGE,HTML_TAG_EXISTS_TBODY 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 This is a multi-part message in MIME format. ------=_NextPart_000_0012_01CF74F1.FD6E5340 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Stefan, The way I try to separate ground and skywave is to look at a = beacon transmission during daylight hours. the groundwave strength seems = to correlate quite well with the minimum in the morning and evening = dips. I find tis gives similar values to those calculated by the late = G3FGQ's GRNDWAV3. The skywave inceases in strength to mid-day at mid path, and no there is = not much if any QSB because I think the skywave is quite stable most of = the day. Yes water does help at all frequencies in a number of ways. There is a = coast effect for station near the sea a bit like focussing. The sea is = generall less "rough" than land in terms of scattering the earth = clinging wave,and of course the loss is less I do think the daytime skywave attenuation is greater than at say 136 = but I have no sensible measrements at 470kHz .....hence the "query" = rather than "statement" :-)) I guess about half the path to Mike is = over water as he is a lot further inland than me..A few more = simultaneous reports would be very interesting. :-)) Alan ----- Original Message -----=20 From: DK7FC=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Wednesday, May 21, 2014 1:35 AM Subject: Re: LF: Re: MF propagation Hi Alan,=20 My observation is that the sky wave attenuation at daytime in summer = is in the order of 40 dB over that distance. So i think it is groundwave = exclusively. Also i can't see QSB over that distances at daytime (maybe = 1 dB). Water nearly seems to act as an amplifier at 630m :-) Could that be a = reason for the choice of the ex marine frequency? ;-) 73, Stefan Am 20.05.2014 21:02, schrieb Alan Melia:=20 Hi Stefan interesting...... at that distance could it just be = different goundwave v skywave phase at the different receivers. You = really need more thn two paths to pin that one :-)) Alan ----- Original Message -----=20 From: DK7FC=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Tuesday, May 20, 2014 12:41 PM Subject: LF: MF propagation Hi MF,=20 Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az=20 2014-05-20 10:10 PA0A 0.475698 +4 0 JO33de 1 = G3XDV IO91vt 466 253 =20 2014-05-20 10:10 PA0A 0.475702 -25 0 JO33de 1 = DK7FC JN49ik 449 157 =20 That shows the difference of MF propagation over sea water and = over land at daytime! (maybe 3 to 6 dB more background noise here?). 73, Stefan ------=_NextPart_000_0012_01CF74F1.FD6E5340 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Stefan, The way I try to separate = ground and=20 skywave is to look at a beacon transmission during daylight hours. the=20 groundwave strength seems to correlate quite well with the minimum in = the=20 morning and evening dips. I find tis gives similar values to those = calculated by=20 the late G3FGQ's GRNDWAV3.
 
The skywave inceases in strength to = mid-day at mid=20 path, and no there is not much if any QSB because I think the skywave is = quite=20 stable most of the day.
 
Yes water does help at all frequencies = in a number=20 of ways. There is a coast effect for station near the sea a bit like = focussing.=20 The sea is generall less "rough" than land in terms of scattering the = earth=20 clinging wave,and of course the loss is less
 
I do think the daytime skywave = attenuation is=20 greater than at say 136 but I have no sensible measrements at 470kHz = .....hence=20 the "query" rather than "statement"  :-))  I guess about half = the path=20 to Mike is over water as he is a lot further inland than me..A few more=20 simultaneous reports would be very interesting. :-))
 
Alan
----- Original Message -----
From:=20 DK7FC=20
Sent: Wednesday, May 21, 2014 = 1:35=20 AM
Subject: Re: LF: Re: MF = propagation

Hi Alan,

My observation is that the sky wave=20 attenuation at daytime in summer is in the order of 40 dB over that = distance.=20 So i think it is groundwave exclusively. Also i can't see QSB over = that=20 distances at daytime (maybe 1 dB).

Water nearly seems to act as = an=20 amplifier at 630m :-) Could that be a reason for the choice of the ex = marine=20 frequency? ;-)

73, Stefan

Am 20.05.2014 21:02, schrieb = Alan=20 Melia:=20
Hi Stefan interesting...... at that = distance=20 could it just be different goundwave v skywave phase at the = different=20 receivers. You really need more thn two paths to pin that one=20 :-))
 
Alan
-----=20 Original Message ----- From:=20 DK7FC To:=20 rsgb_lf_group@blacksheep.org Sent:=20 Tuesday, May 20, 2014 12:41 PM Subject:=20 LF: MF propagation

Hi MF,

Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az
 2014-05-20 10:10   PA0A   0.475698   +4   0   JO33de   1   G3XDV   IO91vt   466   253 
 2014-05-20 10:10   PA0A   0.475702   -25   0   JO33de   1   DK7FC   JN49ik   449   157 


That=20 shows the difference of MF propagation over sea water and over = land at=20 daytime! (maybe 3 to 6 dB more background noise here?).

73, = Stefan
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