Return-Path: Received: from mtain-df11.r1000.mx.aol.com (mtain-df11.r1000.mx.aol.com [172.29.64.223]) by air-da09.mail.aol.com (v129.4) with ESMTP id MAILINDA094-86934d0a8e0530b; Thu, 16 Dec 2010 17:09:09 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-df11.r1000.mx.aol.com (Internet Inbound) with ESMTP id 298E3380000A1; Thu, 16 Dec 2010 17:09:06 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1PTLzj-00026U-LJ for rs_out_1@blacksheep.org; Thu, 16 Dec 2010 22:08:15 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1PTLzj-00026L-0J for rsgb_lf_group@blacksheep.org; Thu, 16 Dec 2010 22:08:15 +0000 Received: from nm17.bullet.mail.ne1.yahoo.com ([98.138.90.80]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1PTLzg-000072-PU for rsgb_lf_group@blacksheep.org; Thu, 16 Dec 2010 22:08:14 +0000 Received: from [98.138.90.57] by nm17.bullet.mail.ne1.yahoo.com with NNFMP; 16 Dec 2010 22:08:05 -0000 Received: from [98.138.88.235] by tm10.bullet.mail.ne1.yahoo.com with NNFMP; 16 Dec 2010 22:08:05 -0000 Received: from [127.0.0.1] by omp1035.mail.ne1.yahoo.com with NNFMP; 16 Dec 2010 22:08:05 -0000 X-Yahoo-Newman-Id: 619821.33970.bm@omp1035.mail.ne1.yahoo.com Received: (qmail 78363 invoked from network); 16 Dec 2010 22:08:05 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=btinternet.com; h=DKIM-Signature:Received:X-Yahoo-SMTP:X-YMail-OSG:X-Yahoo-Newman-Property:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE; b=C+xqcmDXUEKLD0T1aRi2vtB7tJHpJ1BpS7vZ1ChrusRhCiMDZo4Fy+84zgEEHBbecSl/iUnrFwHOX3DaDUQt9x46Z0L34FBn7stlkbXawY+j0o/ZCyyPw6iHqo7rcVIQsbog6fzTchAXX9Llw26nLZSWI4uphlWCFntKWrUvuf4= ; DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=btinternet.com; s=s1024; t=1292537285; bh=FPEd2ftbZV7nHeaMyiaOliIZj5XiGZa/sjPAWvR9wWs=; h=Received:X-Yahoo-SMTP:X-YMail-OSG:X-Yahoo-Newman-Property:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE; b=kA0FjY7jNwUZQClH8Kok9pAe/b4Kk8ImotaVaOnmE+JgFmy1D3uOcIYslbxSDQjH0Mw8kJClykrRORqc0yNwWmLOwgI8L1+ziDibE9ddEe6gWt3e/R3j/On4PVVB4B0eImx7V9I1QnF3/zfIJUkVG8SanvsFhFXbgdsukP0RgGs= Received: from lindavideo (ken.h.wright@86.162.64.127 with login) by smtp145.mail.mud.yahoo.com with SMTP; 16 Dec 2010 14:08:04 -0800 PST X-Yahoo-SMTP: 9Y6mUHuswBAgnrOsukIiNdFDf95uy_Dz34nY1hlg2liKgYD952sjbg-- X-YMail-OSG: UO.OSqMVM1mPSKOBt6uEQp3mDLG_KHcL_ZRfc_33J7ReUFJ 0W0aDQm8NCDykICRsIZoC3iQC5klLtIBJ8p1VBlQ.AolZU7qgj3BIOjz0HyI jaS9TW1EVOsgFgNJ.FrhfWwEGrVqVPm.LVAy3TWHd94OfuOED.B1jYLm.CZ3 9BVU9dCCDQ16k4vp4RNdu_JbfMyHD68xH0Z7CFxXXXgeZ.HaYimUSa4m6_bV TpqIjT7wlX4Y6ZnM1wT1U2Ni9Y6_lIX_flmWrlaqVj93cf8Nn70i2AlDBg.X kJDL.KeCl0MSoHrZht9.C.GqnpDk.bBSKSkoXvNwZ65ejle9h3rGlZd_ztaz 3h8T7mV41w_ofCJjFqzmuDGwlafCXRPT3_9IGJTDOPvhuiW0k X-Yahoo-Newman-Property: ymail-3 Message-ID: <618CDEB5B8894AB7BF89439D85FF042C@lindavideo> From: "Ken" To: References: <005201cb9d61$8bdf3200$0201a8c0@Clemens04> <061B7DFBCF9048E9A7F715A530E1EE96@lindavideo> <00b901cb9d68$551bdc80$0201a8c0@Clemens04> <9F4F2EB43B4846F0B88D2516CA321B66@lindavideo> <00e501cb9d6c$6a7173c0$0201a8c0@Clemens04> Date: Thu, 16 Dec 2010 22:08:02 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5994 DomainKey-Status: good (testing) X-Spam-Score: 3.4 (+++) X-Spam-Report: autolearn=disabled,FORGED_MUA_OUTLOOK=3.36,HTML_MESSAGE=0.001,UNPARSEABLE_RELAY=0.001 Subject: LF: Re: Re: Re: Re: Re: Re: Sound Card mic Impedance Content-Type: multipart/alternative; boundary="----=_NextPart_000_00B8_01CB9D6D.B4ED7C90" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: ** X-Spam-Status: No, hits=2.1 required=5.0 tests=FORGED_MUA_OUTLOOK,HTML_40_50, 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-global-disposition: G X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-m208.2 ; domain : btinternet.com DKIM : fail x-aol-sid: 3039ac1d40df4d0a8e022bc7 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none ------=_NextPart_000_00B8_01CB9D6D.B4ED7C90 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ok Thanks Clemens, I dont think we could have chosen a more interestin= g hobby if we had tried. I will post on the reflector how every things= goes over the weekend and hope to be ready for Chris's next transmiss= ions I an about 15 km line of sight from him. Many thanks for your help. 73. Ken M0KHW ----- Original Message -----=20 From: Clemens Paul=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Thursday, December 16, 2010 9:58 PM Subject: LF: Re: Re: Re: Re: Re: Sound Card mic Impedance Assuming worst case,10kOhm for the soundcard, you had a maximum mismatch loss of only 0,9dB,which is totally neglegible,particularly on LF. Sounds good! 73 Clemens DL4RAJ ----- Original Message -----=20 From: Ken=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Thursday, December 16, 2010 10:37 PM Subject: LF: Re: Re: Re: Re: Sound Card mic Impedance Hi Clemens. How about a 50 ohms in 4k out filter with the knowlege that the so= und card input Z can be anything from 4k upwards. 73. Ken M0KHW ----- Original Message -----=20 From: Clemens Paul=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Thursday, December 16, 2010 9:29 PM Subject: LF: Re: Re: Re: Sound Card mic Impedance The 50-Ohm-termination at the output of the LP filter represents= a 50-Ohm-*source* which is looking into the input impedance of the= soundcard. Hence the gross (power-)mismatch (SWR 80). For such high impedances at vlf (=3Daudio) frequencies voltage matching would be much more efficient. 73 Clemens DL4RAJ ----- Original Message -----=20 From: Ken=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Thursday, December 16, 2010 10:04 PM Subject: LF: Re: Re: Sound Card mic Impedance Hi Clements. Are you sure, shunting a 50 ohm resistor with 4k ohms reduces= it down to 49.38 ohms or am I missing something?. 73. Ken M0KHW=20 ----- Original Message -----=20 From: Clemens Paul=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Thursday, December 16, 2010 8:40 PM Subject: LF: Re: Sound Card mic Impedance Ken, >I am doing a Low Pass Filter to use with Winrad, F1, 20kHz= , F2, 30 kHz, 100kHz -80 dB (theoretical) with a >characteristic imped= ance of 50 ohms, with this high input impedance I can locate the filte= r very close to the sound >card mic input and terminate the filter out= put with a 50 ohm resistor. Assuming 4kOhm input impedance of the soundcard this will ca= use a mismatch loss of around 13dB (95% loss) which may or may not cause concern= depending of the signal level of your antenna. 73 Clemens DL4RAJ ----- Original Message -----=20 From: Ken=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Thursday, December 16, 2010 9:06 PM Subject: LF: Sound Card mic Impedance Thank you all LFs. Thank you for all the info that you sent me, it looks they= can be anything from 4k ohms upwards, this is ok for me, I am doing= a Low Pass Filter to use with Winrad, F1, 20kHz, F2, 30 kHz, 100kHz= -80 dB (theoretical) with a characteristic impedance of 50 ohms, with= this high input impedance I can locate the filter very close to the= sound card mic input and terminate the filter output with a 50 ohm re= sistor. Hopefully this will eliminate the BC intermod I was experienci= ng when trying to receive Chris G3XIZ the other day. 73 Ken M0KHW I091TV=20 ------=_NextPart_000_00B8_01CB9D6D.B4ED7C90 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Ok Thanks Clemens, I dont think we co= uld have=20 chosen a more interesting hobby if we had tried. I will post on the re= flector=20 how every things goes over the weekend and hope to be ready for Chris'= s next=20 transmissions I an about 15 km line of sight from him.
Many thanks for your help.
 
73.
Ken
M0KHW
----- Original Message -----
Sent: Thursday, December 16,= 2010 9:58=20 PM
Subject: LF: Re: Re: Re: Re:= Re: Sound=20 Card mic Impedance

Assuming worst case,10kOhm for the= =20 soundcard,
you had a maximum mismatch loss of= =20 only
0,9dB,which is totally neglegible,p= articularly on=20 LF.
Sounds good!
 
73
Clemens
DL4RAJ
----- Original Message -----
From:=20 Ken
Sent: Thursday, December 16= , 2010 10:37=20 PM
Subject: LF: Re: Re: Re: Re= : Sound Card=20 mic Impedance

Hi Clemens.
How about a 50 ohms in 4k ou= t filter with=20 the knowlege that the sound card input Z can be anything from 4k= =20 upwards.
 
73.
Ken
M0KHW
----- Original Message -----
From:=20 Clemens= Paul
Sent: Thursday, December= 16, 2010=20 9:29 PM
Subject: LF: Re: Re: Re:= Sound Card=20 mic Impedance

The 50-Ohm-termination at the= output of the=20 LP filter represents a
50-Ohm-*source* which is looking into the input impedanc= e of the=20 soundcard.
Hence the gross (power-)mismatc= h (SWR=20 80).
For such high impedances at&nbs= p;vlf=20 (=3Daudio) frequencies
voltage matching would be = much more=20 efficient.
 
73
Clemens
DL4RAJ<= /DIV>
 
 
----- Original Message -----=
From:=20 Ken
Sent: Thursday, Decembe= r 16, 2010=20 10:04 PM
Subject: LF: Re: Re: So= und Card mic=20 Impedance

Hi Clements.
Are you sure, shunting a 50= ohm resistor=20 with 4k ohms reduces it down to 49.38 ohms or am I missing=20 something?.
73.
Ken
M0KHW 
----- Original Message -----=
From:=20 Cleme= ns Paul=20
Sent: Thursday, Decem= ber 16, 2010=20 8:40 PM
Subject: LF: Re: Soun= d Card mic=20 Impedance

Ken,
 
>I am doing  a Low= Pass Filter to=20 use with Winrad, F1, 20kHz, F2, 30 kHz, 100kHz -80 dB=20 (theoretical) with a >characteristic impedance of 50= ohms,=20 with this high input impedance I can locate the fi= lter very=20 close to the sound >card mic input and terminate the filt= er output=20 with a 50 ohm resistor.
 
Assuming 4kOhm input impeda= nce of the=20 soundcard this will cause a mismatch loss
of around 13dB (95% loss)= which may or=20 may not cause concern depending of the signal=20 level of
your antenna.
 
 
73
Clemens
DL4RAJ
----- Original Message ---= --
From:=20 Ken
Sent: Thursday, Dec= ember 16,=20 2010 9:06 PM
Subject: LF: Sound= Card mic=20 Impedance

Thank you all LFs.=
Thank you for all the inf= o that you=20 sent me, it looks they can be anything from 4k ohms upward= s, this is=20 ok for me, I am doing  a Low Pass Filter to use with= Winrad,=20 F1, 20kHz, F2, 30 kHz, 100kHz -80 dB (theoretical) wi= th a=20 characteristic impedance of 50 ohms, with this high input= =20 impedance I can locate the filter very close to= the sound=20 card mic input and terminate the filter output with a 50= ohm=20 resistor. Hopefully this will eliminate the BC interm= od I was=20 experiencing when trying to receive Chris G3XIZ the other= =20 day.
 
73
Ken
M0KHW  =20 I091TV 
------=_NextPart_000_00B8_01CB9D6D.B4ED7C90--