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[195.171.43.25]) by mx.google.com with ESMTP id cd6si10731847wjc.57.1969.12.31.16.00.00; Wed, 11 Sep 2013 08:02:28 -0700 (PDT) Received-SPF: neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) client-ip=195.171.43.25; Authentication-Results: mx.google.com; spf=neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) smtp.mail=owner-rsgb_lf_group@blacksheep.org; dkim=pass header.i=@mx.aol.com Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1VJlT1-0004vI-U4 for rs_out_1@blacksheep.org; Wed, 11 Sep 2013 15:32:27 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1VJlT1-0004v5-AR for rsgb_lf_group@blacksheep.org; Wed, 11 Sep 2013 15:32:27 +0100 Received: from omr-m01.mx.aol.com ([64.12.143.75]) by relay1.thorcom.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.77) (envelope-from ) id 1VJlSy-0001Vw-5P for rsgb_lf_group@blacksheep.org; Wed, 11 Sep 2013 15:32:26 +0100 Received: from mtaout-da01.r1000.mx.aol.com (mtaout-da01.r1000.mx.aol.com [172.29.51.129]) by omr-m01.mx.aol.com (Outbound Mail Relay) with ESMTP id 08C2A701065E8; Wed, 11 Sep 2013 10:32:20 -0400 (EDT) Received: from [192.168.1.65] (host-92-7-226-93.as43234.net [92.7.226.93]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mtaout-da01.r1000.mx.aol.com (MUA/Third Party Client Interface) with ESMTPSA id 3742FE0000CF; Wed, 11 Sep 2013 10:32:19 -0400 (EDT) Message-ID: <52307EF1.5050009@aol.com> Date: Wed, 11 Sep 2013 15:32:17 +0100 From: pat Organization: G4GVW User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130803 Thunderbird/17.0.8 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org CC: Alan Melia References: <522FF986.5010103@virginbroadband.com.au> <1378890643.59333.YahooMailNeo@web133205.mail.ir2.yahoo.com> <57D31B165A1B4B97B69CC60A4D47DB55@gnat> In-Reply-To: <57D31B165A1B4B97B69CC60A4D47DB55@gnat> x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20121107; t=1378909939; bh=us79897WcFB8+2riQasAlqDnUpD6tA7umYuVrVTk4Vs=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=BfYb46baEs5uiVltZrlD9nzsdhowb87nVG2OcRtpY7vWa6FtjmBRAi8Ua+Zm90bCb obCOeo4X4xaFFBX7WEjOjgO54mJl/wXEw7bGL5D9jHAlEjhFljvzoX6hP1RAfcmz5/ Yu089jJ7u1Pd8hPyh5E5P3nMHxNAS/fhBci7ASFI= x-aol-sid: 3039ac1d338152307ef31ea6 X-AOL-IP: 92.7.226.93 X-Spam-Score: -0.8 (/) 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: Hmmm! Interesting one. I have always assumed that the first point at which the signal(s) caused the electromagnetic field(s) to develop into voltages/currents and might then be subject to further processing occurred at the connection to the antenna or feeder. From that assumption would follow the surmise that Luxembourg/Gorky or other effects would result from the phase etc. relationships at that point and then perhaps be followed by 'distortions' etc. in non-linear stages. This thought follows from the concept that there is 'nothing' going on until the radiated field(s) of RF energy excite current flow in the antenna thus giving rise to voltages at the receiver input. Maybe this is simplistic but it is how I have understood it for more than 55 years. [...] Content analysis details: (-0.8 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [64.12.143.75 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (g4gvw[at]aol.com) -0.0 SPF_PASS SPF: sender matches SPF record -0.8 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 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: 78d45eae26b8e09cb3b944588f353c28 Subject: Re: LF: Radio signals Content-Type: multipart/alternative; boundary="------------090805090404080107040700" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_20_30,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 Status: O X-Status: X-Keywords: X-UID: 2708 This is a multi-part message in MIME format. --------------090805090404080107040700 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Hmmm! Interesting one. I have always assumed that the first point at which the signal(s) caused the electromagnetic field(s) to develop into voltages/currents and might then be subject to further processing occurred at the connection to the antenna or feeder. From that assumption would follow the surmise that Luxembourg/Gorky or other effects would result from the phase etc. relationships at that point and then perhaps be followed by 'distortions' etc. in non-linear stages. This thought follows from the concept that there is 'nothing' going on until the radiated field(s) of RF energy excite current flow in the antenna thus giving rise to voltages at the receiver input. Maybe this is simplistic but it is how I have understood it for more than 55 years. 73 On 11/09/13 10:55, Alan Melia wrote: > Hi Edgar.......Or if the receiver is operating in a linear > mode.....then straight addition, but probably only with SSB detection, > an AM demodulater diode is non-linear :-)) > If you add the signals coming from the same transmitter but over > slightly different paths which alters the phase at the receiver, you > get fading but this is only obvious is one or both path lengths changes. > Alan > G3NYK > > ----- Original Message ----- > *From:* M0FMT > *To:* rsgb_lf_group@blacksheep.org > > *Sent:* Wednesday, September 11, 2013 10:10 AM > *Subject:* Re: LF: Radio signals > > Hi > Non linearity in the first RX stage? Caused by a fault in the > stage or over driving of the stage.Or some very bad corrosion in > the joints of the antenna leads. etc etc. Check your RX, try > fitting an attenuator in the antenna lead or shorten your antenna. > Or for a more esoteric explanation > http://en.wikipedia.org/wiki/Luxemburg%E2%80%93Gorky_effect > 73 es GL Pete M0FMT IO91UX > > *From:* edgar > *To:* "600m@yahoogroups.com" <600m@yahoogroups.com>; > "rsgb_lf_group@blacksheep.org" > *Sent:* Wednesday, 11 September 2013, 6:03 > *Subject:* LF: Radio signals > > Hi Group, > > What is the mechanism for the way radio signals combine in the air? > > For example > > 1.There are two transmitters each sending out the same fixed > frequency > sine wave signal. > > 2. There are no other signals in space, and no background noise. > > 3. There are no propagation factors modifying the signals. > > e.g. buildings, ionosphere layers. > > 4. Both transmitters are the same distance from the receiver. > > 5. Both signals have the same polarisation. > > How have the signals combined when they reach a receiving antenna > at a > reasonable distance from both transmitters? > > It the process addition, multiplication or some other process? > > Regards, Edgar > Moonah, Tasmania. > > > > > > > > -- 73 de pat g4gvw es gd dx qth nr Felixstowe East Coast UK --------------090805090404080107040700 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit
Hmmm! Interesting one. I have always assumed that the first point at which the signal(s) caused the electromagnetic field(s) to develop into voltages/currents and might then be subject to further processing occurred at the connection to the antenna or feeder. From that assumption would follow the surmise that Luxembourg/Gorky or other effects would result from the phase etc. relationships at that point and then perhaps be followed by 'distortions' etc. in non-linear stages. This thought follows from the concept that there is 'nothing' going on until the radiated field(s) of RF energy excite current flow in the antenna thus giving rise to voltages at the receiver input. Maybe this is simplistic but it is how I have understood it for more than 55 years.

73

On 11/09/13 10:55, Alan Melia wrote:
Hi Edgar.......Or if the receiver is operating in a linear mode.....then straight addition, but probably only with SSB detection, an AM demodulater diode is non-linear :-))
If you add the signals coming from the same transmitter but over slightly different paths which alters the phase at the receiver, you get fading but this is only obvious is one or both path lengths changes.
 
Alan
G3NYK
----- Original Message -----
From: M0FMT
Sent: Wednesday, September 11, 2013 10:10 AM
Subject: Re: LF: Radio signals

Hi
 
Non linearity in the first RX stage? Caused by a fault in the stage or over driving of the stage.Or some very bad corrosion in the joints of the antenna leads. etc etc. Check your RX,  try fitting an attenuator in the antenna lead or shorten your antenna.
 
73 es GL Pete M0FMT IO91UX


Hi Group,

What is the mechanism for the way radio signals combine in the air?

For example

1.There are two transmitters each sending out the same fixed frequency
sine wave signal.

2. There are no other signals in space, and no background noise.

3. There are no propagation factors modifying the signals.

e.g. buildings, ionosphere layers.

4. Both transmitters are the same distance from the receiver.

5. Both signals have the same polarisation.

How have the signals combined when they reach a receiving antenna at a
reasonable distance from both transmitters?

It the process addition, multiplication or some other process?

Regards, Edgar
Moonah, Tasmania.










-- 
73 de pat g4gvw
es gd dx
qth nr Felixstowe
East Coast UK
--------------090805090404080107040700--