X-GM-THRID: 1234186425068528496 X-Gmail-Labels: rsgb lf Delivered-To: daveyxm@gmail.com Received: by 10.115.73.6 with SMTP id a6cs689032wal; Thu, 19 Apr 2007 12:44:56 -0700 (PDT) Received: by 10.78.142.14 with SMTP id p14mr356178hud.1177011895636; Thu, 19 Apr 2007 12:44:55 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mx.google.com with ESMTP id 72si3476299ugb.2007.04.19.12.44.52; Thu, 19 Apr 2007 12:44:55 -0700 (PDT) Received-SPF: neutral (google.com: 193.82.116.20 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) DomainKey-Status: bad (test mode) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1HecSl-0001bV-1T for rs_out_1@blacksheep.org; Thu, 19 Apr 2007 20:38:39 +0100 Received: from [193.82.59.130] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1HecSk-0001bM-H4 for rsgb_lf_group@blacksheep.org; Thu, 19 Apr 2007 20:38:38 +0100 Received: from web86402.mail.ird.yahoo.com ([217.146.188.119]) by relay2.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1HecSj-0005A0-7x for rsgb_lf_group@blacksheep.org; Thu, 19 Apr 2007 20:38:38 +0100 Received: (qmail 93513 invoked by uid 60001); 19 Apr 2007 19:38:28 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=btinternet.com; h=X-YMail-OSG:Received:Date:From:Subject:To:MIME-Version:Content-Type:Content-Transfer-Encoding:Message-ID; b=tM/vuE1M3HclL55VDV+nVspcKVJ1G6KsSQ48pnT6GGbWDQPGdf8cG+QJdTBy8WwaCb88pXcfvfMjT9N+JY6cTkUNZxW+iY/NhlmYIKRtLCJ6w/Lb0+XmC4/lmO5EwtsubWyousrndF12R/fHZr0585PjXIi6x5aC0VxkGZTKR0Q=; X-YMail-OSG: 8qB_s3wVM1mvGsXI.e_IfLywyItO3dgSqxn_rLkUS0.euyMYizhva0is5D7Vr56piKwo4D6cI6OVzweZt8JXqoPFPb8_yPEXu4evRxBFYraW2ajm Received: from [80.6.40.58] by web86402.mail.ird.yahoo.com via HTTP; Thu, 19 Apr 2007 20:38:28 BST Date: Thu, 19 Apr 2007 20:38:28 +0100 (BST) From: CHRISTOPHER OSBORN To: LF group MIME-Version: 1.0 Message-ID: <791814.92220.qm@web86402.mail.ird.yahoo.com> DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: LF: RX Sensitivity on 500 kHz Content-Type: multipart/alternative; boundary="0-593754440-1177011508=:92220" Content-Transfer-Encoding: 8bit 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 Status: O X-Status: X-Keywords: X-UID: 1873 --0-593754440-1177011508=:92220 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Dear LF, I have just calibrated my 500 kHz DC RX using an AF-derived agc and s-meter. The agc / s-meter are driven after a narrow audio filter. I used a signal generator and a switched attenuator. Attaching my receive loop aerial rotated for minimum local QRM I have a usual noise level of about 7 dB (uV) - S 4 - 5 (assuming S9 = 50 uV) The main station end fed wire aerial gives a noise level of 16 dB (uV) - S6 !! At times the local noise level is significantly worse. My apologies to those who have called me and have not been heard. The RX internal noise with aerials disconnected is well below 0 dB (uV). Assuming there's no flaw in my calibration method I have registered the following stations' readings, using the loop rotated for optimum signal: G3KEV 32 dB (uV) G3ROO 25 " G3GRO 19 " G3UNT 18 " Any comments or suggestions are welcome. Is there a list of 500 kHz operators ? To date I have registered 19 of whom I have worked 14. 73 Chris G3XIZ --------------------------------- Yahoo! Mail is the world's favourite email. Don't settle for less, sign up for your freeaccount today. --0-593754440-1177011508=:92220 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Dear LF,

I have just calibrated my 500 kHz DC RX using an AF-derived agc and s-meter.
The agc / s-meter are driven after a narrow audio filter.
I used a signal generator and a switched attenuator.

Attaching my receive loop aerial rotated for minimum local QRM I have a usual noise level of about 7 dB (uV) - S 4 - 5  (assuming S9 = 50 uV)
The main station end fed wire aerial gives a noise level of 16 dB (uV) - S6  !!
At times the local noise level is significantly worse.
My apologies to those who have called me and have not been heard.

The RX internal noise with aerials disconnected is well below 0 dB (uV).

Assuming there's no flaw in my calibration method I have registered the following
stations' readings, using the loop rotated for optimum signal:

G3KEV     32  dB (uV)
G3ROO    25    "
G3GRO    19    "
G3UNT     18    "

Any comments or suggestions are welcome.

Is there a list of 500 kHz operators ?
To date I have registered 19 of whom I have worked 14.

73 Chris G3XIZ




Yahoo! Mail is the world's favourite email. Don't settle for less, sign up for your free account today. --0-593754440-1177011508=:92220--