Return-Path: Received: from rly-mf02.mx.aol.com (rly-mf02.mail.aol.com [172.20.29.172]) by air-mf03.mail.aol.com (v123.4) with ESMTP id MAILINMF032-94449cde2db1fd; Sat, 28 Mar 2009 04:42:11 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-mf02.mx.aol.com (v123.4) with ESMTP id MAILRELAYINMF022-94449cde2db1fd; Sat, 28 Mar 2009 04:42:05 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1LnU68-0003Dn-WD for rs_out_1@blacksheep.org; Sat, 28 Mar 2009 08:41:00 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1LnU68-0003De-IL for rsgb_lf_group@blacksheep.org; Sat, 28 Mar 2009 08:41:00 +0000 Received: from imo-m25.mx.aol.com ([64.12.137.6] helo=imo-m25.mail.aol.com) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1LnU66-0006ux-DU for rsgb_lf_group@blacksheep.org; Sat, 28 Mar 2009 08:41:00 +0000 Received: from MarkusVester@aol.com by imo-m25.mx.aol.com (mail_out_v39.1.) id l.c24.59af079b (37518) for ; Sat, 28 Mar 2009 04:41:02 -0400 (EDT) Received: from Silver (g229123176.adsl.alicedsl.de [92.229.123.176]) by cia-ma08.mx.aol.com (v123.3) with ESMTP id MAILCIAMA083-928e49cde28950; Sat, 28 Mar 2009 04:40:48 -0400 Message-ID: <02803F019014433F8238BE62E2FC3BAD@Silver> From: "Markus Vester" To: References: <8bf118410903270647t5ebb0cedi82b96e2ea73075bd@mail.gmail.com> <20090327162720.6et0xg2farr40g0c@webmail4.kuleuven.be> Date: Sat, 28 Mar 2009 08:40:39 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5512 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Spam-Flag:NO X-Karma: unknown: X-Spam-Score: 3.4 (+++) X-Spam-Report: autolearn=disabled,FORGED_MUA_OUTLOOK=3.36,HTML_MESSAGE=0.001 Subject: LF: Miles per Watt? Content-Type: multipart/alternative; boundary="----=_NextPart_000_0003_01C9AF80.DFA1D710" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: ** X-Spam-Status: No, hits=2.4 required=5.0 tests=FORGED_MUA_OUTLOOK,HTML_30_40, 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_0003_01C9AF80.DFA1D710 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Gentlemen, sorry, but in my humble opinion a figure like "miles per watt" just doesn't=20= make any sense. Fieldstrength goes with the square root of power, but decays at least propor= tional to inverse distance. Anyone could claim 1000 lightyears (1E16 km !) p= er watt, simply by feeding -165 dBm into a pair of 144 MHz dipoles spaced by= 0.3 m and a QRSS3 receiver. A more appropiate figure would be km/sqrt(watt). Best regards, Markus (DF6NM) ----- Original Message -----=20 From: Rik Strobbe=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Friday, March 27, 2009 3:27 PM Subject: Re: LF: Lazy Man's CW made it to Venus and back Dave, If I got it right their ran 5kW into a 20m dish at 2.4GHz. The dish gain should be about 50dBd. 50dB =3D 100000 times power gain, thus ERP =3D +/- 500MW The distance to Venus (today) is 0.281 AU =3D 42 milion km =3D 26.1 milion= miles Total distance is 82 milion km / 52.2 milion miles, what makes it +/- 0.1=20= miles per Watt. That value is not spectacular at all, but take into account that Venus is=20= a pretty bad reflector and the signal has to go twice trough the atmoshpere=20= and ionospere. 73, Rik ON7YD Quoting Dave Pick : > How many miles per Watt is that?!! > > Dave 'YXM ------=_NextPart_000_0003_01C9AF80.DFA1D710 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Gentlemen,
 
sorry, but in my humble opinion a figure&nb= sp;like=20 "miles per watt" just doesn't make any sense.
 
Fieldstrength goes with the square roo= t of=20 power, but decays at least proportional to inverse distance.=20 Anyone could claim 1000 lightyears (= 1E16 km=20 !) per watt, simply by feeding -165 dBm into a pair of 144 MHz=20 dipoles spaced by 0.3 m and a QRSS3 receiver.
 
A more appropiate figure would be=20 km/sqrt(watt).
 
Best regards,
Markus (DF6NM)
 
----- Original Message -----
Rik Strobbe
Sent: Friday, March 27, 2009 3:27=20 PM
Subject: Re: LF: Lazy Man's CW made= it to=20 Venus and back

Dave,

If I got it= right=20 their ran 5kW into a 20m dish at 2.4GHz.
The dish gain should be about=20 50dBd.
50dB =3D 100000 times power gain, thus ERP =3D +/- 500MW
The=20= distance=20 to Venus (today) is 0.281 AU =3D 42 milion km =3D 26.1 milion miles
Tot= al=20 distance is 82 milion km / 52.2 milion miles, what makes it +/- 0.1 m= iles=20 per Watt.
That value is not spectacular at all, but take into account t= hat=20 Venus is a pretty bad reflector and the signal has to go twice trough= =20 the atmoshpere and ionospere.

73, Rik  ON7YD

Quoti= ng=20 Dave Pick <daveyxm@google= mail.com>:

>=20 How many miles per Watt is that?!!
>
> Dave=20 'YXM
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