Return-Path: Received: (qmail 2793 invoked from network); 27 Jul 2002 09:04:30 -0000 Received: from murphys.services.quay.plus.net (212.159.14.225) by mailstore with SMTP; 27 Jul 2002 09:04:30 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 22112 invoked from network); 27 Jul 2002 09:04:31 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from post.thorcom.com (193.82.116.70) by murphys.services.quay.plus.net with SMTP; 27 Jul 2002 09:04:31 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 17YNS9-00049S-00 for rsgb_lf_group-outgoing@blacksheep.org; Sat, 27 Jul 2002 10:01:33 +0100 Received: from cmailenv1.svr.pol.co.uk ([213.218.77.53]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 17YNS9-00049N-00 for rsgb_lf_group@blacksheep.org; Sat, 27 Jul 2002 10:01:33 +0100 Received: from [62.21.150.138] (helo=w8k3f0.freeler.nl) by cmailENV1.svr.pol.co.uk with esmtp (Exim 3.35 #1) id 17YNS6-000082-00 for rsgb_lf_group@blacksheep.org; Sat, 27 Jul 2002 09:01:31 +0000 Message-ID: <5.1.0.14.0.20020727104300.00a2ae30@POP3.freeler.nl> X-Sender: FRE0000086604@POP3.freeler.nl X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Sat, 27 Jul 2002 11:03:30 +0200 To: "LF-Group" From: "Dick Rollema" Subject: LF: Power of Donebach 153kHz TX MIME-Version: 1.0 Content-Type: text/html; charset=windows-1252 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Content-transfer-encoding: 8bit To All from PA0SE,

Sorry to bother you again with a field strength story. But the delete key is within easy reach...

The Deutschlandfunk Donebach transmitter at 153kHz is on again. At 0840 UTC today I measured its field strength as 5.6millivolt/metre.
Using the CCIR groundwave propagation curve that produces plausible results on DCF39 and M0BMU the Effective Monopole Radiated Power (EMRP) comes out as 157kW.

On the Internet I found transmitter power is 500kW. But there are two 363m high aerial masts. This suggests a directive array. As the transmissions are probably not meant for the Netherlands we may get only part of the full blast.

Measuring with the SPM-12 in 25Hz bandwidth the reading moved up and down a bit with the modulation. Perhaps some power (and money) saving controlled carrier system is used. It could also be that some of the lowest modulation frequency components are passed by the 25Hz  I.F. filter. But other BC stations on LF do not show the effect.

73, Dick, PA0SE