Return-Path: Received: (qmail 10528 invoked from network); 14 Aug 2001 15:21:51 -0000 Received: from unknown (HELO warrior-inbound.services.quay.plus.net) (212.159.14.227) by excalibur.plus.net with SMTP; 14 Aug 2001 15:21:51 -0000 Received: (qmail 10360 invoked from network); 14 Aug 2001 15:21:42 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by warrior with SMTP; 14 Aug 2001 15:21:42 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.16 #2) id 15WftI-00075A-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 14 Aug 2001 16:14:00 +0100 Received: from relay.dera.gov.uk ([192.5.29.49]) by post.thorcom.com with smtp (Exim 3.16 #2) id 15WftE-000755-00 for rsgb_lf_group@blacksheep.org; Tue, 14 Aug 2001 16:13:56 +0100 Content-Transfer-Encoding: 8bit Received: (qmail 32380 invoked from network); 14 Aug 2001 16:13:16 +0100 Received: from trtnmail.dera.gov.uk (146.80.9.56) by relay.dera.gov.uk with SMTP; 14 Aug 2001 16:13:16 +0100 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 21227 invoked from network); 14 Aug 2001 16:15:28 +0100 Received: (ofmipd 192.5.29.90); 14 Aug 2001 15:15:06 -0000 Received: by bob.dera.gov.uk; (8.8.8/1.3/10May95) id QAA30311; Tue, 14 Aug 2001 16:19:29 +0100 (BST) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: (qmail 25162 invoked from network); 14 Aug 2001 16:04:05 -0000 Received: from gauntlet.mail.dera.gov.uk (172.16.9.10) by baton.dera.gov.uk with SMTP; 14 Aug 2001 16:04:05 -0000 Received: by gauntlet.mail.dera.gov.uk; id PAA04488; Tue, 14 Aug 2001 15:50:36 GMT Received: from unknown(10.71.64.31) by gauntlet.mail.dera.gov.uk via smap (3.2) id xma004473; Tue, 14 Aug 01 15:50:27 GMT Received: from mailex.dera.gov.uk (unverified) by mailguard.dera.gov.uk (Content Technologies SMTPRS 4.1.5) with SMTP id for ; Tue, 14 Aug 2001 16:13:34 +0100 Received: (qmail 5131 invoked from network); 14 Aug 2001 15:01:01 +0100 Date: 14 Aug 2001 16:11:22 +0100 Message-ID: <7D653C9C42F5D411A27C00508BF8803D55C596@PDW-MAIL-R1> From: "Andrew Talbot" To: rsgb_lf_group@blacksheep.org X-5Received: from softdnserror (HELO cchecker.dstl.gov.uk) (192.168.248.52) by mailex.dstl.gov.uk with SMTP; 14 Aug 2001 14:01:01 -0000 X-4Received: from FRN-MAIL-R3.dstl.gov.uk (unverified) by cchecker.dstl.gov.uk (Content Technologies SMTPRS 4.1.2) with ESMTP id for ; Tue, 14 Aug 2001 15:00:41 +0100 X-3Received: by frn-mail-r3.dstl.gov.uk with Internet Mail Service (5.5.2650.21)id ; Tue, 14 Aug 2001 16:11:20 +0100 Subject: RE: LF: Radiated power at PA0SE MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2650.21) Content-Type: text/plain; charset=iso-8859-1; format=flowed Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: > ...................... > I found a FS of 370 microvolt/metre. From this follows an impressive radiated > power (EIRP) of 52 milliwatt. >I guess). what program did you use ? You don't need a programme, just work from basic theory ...... >From Ohms law E^2 / Zo (of free space = 377 ohms) = Watts / m^2 At a distance R from an omnidirectional radiator (the definition of EIRP), all the transmitted power is spread out over a sphere of surface area 4 * PI * R^2, which is equal to your measured power density in W/m^2 So EIRP of Tx = (Watts / m^2) * 4.PI.R^2 = E^2 / 4 * PI * R^2 where E isthe measured field strength in Volts / metre Then if you really want it in terms of dipole ERP, just subtract the magic figure of 2.14dB ( or divide by 1.64) , ie. the gain of a dipole. Andy G4JNT -- The Information contained in this E-Mail and any subsequent correspondence is private and is intended solely for the intended recipient(s). For those other than the recipient any disclosure, copying, distribution, or any action taken or omitted to be taken in reliance on such information is prohibited and may be unlawful.