Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id v9I9Hpnf027685 for ; Wed, 18 Oct 2017 11:17:54 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1e4kPJ-0000C7-IO for rs_out_1@blacksheep.org; Wed, 18 Oct 2017 10:12:57 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1e4kPJ-0000By-00 for rsgb_lf_group@blacksheep.org; Wed, 18 Oct 2017 10:12:57 +0100 Received: from mout02.posteo.de ([185.67.36.66]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1e4kPG-0003xo-29 for rsgb_lf_group@blacksheep.org; Wed, 18 Oct 2017 10:12:55 +0100 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id 22B122098D for ; Wed, 18 Oct 2017 11:12:53 +0200 (CEST) Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 3yH5tr1kV2z10H3 for ; Wed, 18 Oct 2017 11:12:52 +0200 (CEST) Message-ID: <59E71B13.9010604@posteo.de> Date: Wed, 18 Oct 2017 11:12:51 +0200 From: DK7FC User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <15f2c1f0c6c-c08-3ed7@webjas-vab156.srv.aolmail.net> In-Reply-To: <15f2c1f0c6c-c08-3ed7@webjas-vab156.srv.aolmail.net> X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Am 17.10.2017 22:55, schrieb Markus Vester: > As a crude first Approximation to the model, we might look only at > groundwave and single-hop skywave. For 230 km range, the geometrical > path difference would be 63.3 km (1.37 lambda) for 90 km reflection > height (night), and 40.3 km (0.87 lambda) for 70 km (day). [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message X-Scan-Signature: 6be9408bcc63ba5aab6f1e66e2d5b7ce Subject: Re: VLF: EbNaut on 2 frequencies Content-Type: multipart/alternative; boundary="------------090101040105090107050001" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=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 This is a multi-part message in MIME format. --------------090101040105090107050001 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Am 17.10.2017 22:55, schrieb Markus Vester: > As a crude first Approximation to the model, we might look only at > groundwave and single-hop skywave. For 230 km range, the geometrical > path difference would be 63.3 km (1.37 lambda) for 90 km reflection > height (night), and 40.3 km (0.87 lambda) for 70 km (day). Ah, so we would expect an optimum performance on 7.44 kHz during daytime and 4.74 kHz during the nights between DK7FC and DL0AO. The phase shift would be just 360 deg or 1 lambda then... For *5170 Hz* it is 1.09 lambda during the nights and 1.44 lambda during the days. That's even closer to 1 lambda or 1.5 lambda, so here we would expect an even stronger experessed day/night difference, if this propagation model is reasonable over that distance. We will check that! On 2970 Hz: 0.62 lambda at night and 0.4 lambda during daytime, so both is not really ideal. 970 Hz: 0.21 lambda at night and 0.13 lambda during daytime. That's fine! So we should prefer 970 Hz, hahaaa!! 73, Stefan --------------090101040105090107050001 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 7bit

Am 17.10.2017 22:55, schrieb Markus Vester:
As a crude first Approximation to the model, we might look only at groundwave and single-hop skywave. For 230 km range, the geometrical path difference would be 63.3 km (1.37 lambda) for 90 km reflection height (night), and 40.3 km (0.87 lambda) for 70 km (day).

Ah, so we would expect an optimum performance on 7.44 kHz during daytime and 4.74 kHz during the nights between DK7FC and DL0AO. The phase shift would be just 360 deg or 1 lambda then...

For 5170 Hz it is 1.09 lambda during the nights and 1.44 lambda during the days. That's even closer to 1 lambda or 1.5 lambda, so here we would expect an even stronger experessed day/night difference, if this propagation model is reasonable over that distance.
We will check that!

On 2970 Hz: 0.62 lambda at night and 0.4 lambda during daytime, so both is not really ideal.

970 Hz: 0.21 lambda at night and 0.13 lambda during daytime. That's fine! So we should prefer 970 Hz, hahaaa!!

73, Stefan
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