Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-ma04.r1000.mx.aol.com (Internet Inbound) with ESMTP id D8CA0380000A7; Sat, 30 Jun 2012 08:31:16 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Skwou-0006Ft-5n for rs_out_1@blacksheep.org; Sat, 30 Jun 2012 13:30:36 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Skwot-0006Fk-MT for rsgb_lf_group@blacksheep.org; Sat, 30 Jun 2012 13:30:35 +0100 Received: from relay.uni-heidelberg.de ([129.206.100.212]) by relay1.thorcom.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.77) (envelope-from ) id 1Skwor-0005hN-Hj for rsgb_lf_group@blacksheep.org; Sat, 30 Jun 2012 13:30:34 +0100 Received: from freitag.iup.uni-heidelberg.de (freitag.iup.uni-heidelberg.de [129.206.29.204]) by relay.uni-heidelberg.de (8.14.1/8.14.1) with ESMTP id q5UCUWWA007502 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Sat, 30 Jun 2012 14:30:32 +0200 Received: from [129.206.22.206] (pc206.iup.uni-heidelberg.de [129.206.22.206]) by freitag.iup.uni-heidelberg.de (8.12.11.20060308/8.11.2) with ESMTP id q5UCUWVt018362 for ; Sat, 30 Jun 2012 14:30:32 +0200 Message-ID: <4FEEF0F5.80902@iup.uni-heidelberg.de> Date: Sat, 30 Jun 2012 14:28:37 +0200 From: =?ISO-8859-15?Q?Stefan_Sch=E4fer?= User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <00a901cd563a$b02b6be0$0200a8c0@boxa> <4FEE2407.3050603@iup.uni-heidelberg.de> <4FEEC581.7020804@kabelmail.de> In-Reply-To: <4FEEC581.7020804@kabelmail.de> X-Spam-Score: -0.7 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Hi Tom. Thanks. Yes, i have the 2 V rms in mind. It was stated in the datasheet. I intend to use a series configuration of 3 antiparallel 1N4148 diodes on the input to protect the filter. At 50 Ohm, the leveles are hopefully below 2 V rms. Otherwise i will use a stepped attenuator in series of course (if clipping occurs). [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [129.206.100.212 listed in list.dnswl.org] -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message X-Scan-Signature: f64a6c8ea7591cecbecc6db95ffdd328 Subject: Re: LF: RE: Fwd: Help needed, mechanical filters Content-Type: multipart/alternative; boundary="------------000303040700030005070307" 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 x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:384063648:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d600c4feef19408a2 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. --------------000303040700030005070307 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by relay.uni-heidelberg.de id q5UCUWWA007502 Hi Tom. Thanks. Yes, i have the 2 V rms in mind. It was stated in the datasheet.=20 I intend to use a series configuration of 3 antiparallel 1N4148 diodes=20 on the input to protect the filter. At 50 Ohm, the leveles are hopefully=20 below 2 V rms. Otherwise i will use a stepped attenuator in series of=20 course (if clipping occurs). 73, Stefan Am 30.06.2012 11:23, schrieb DK1IS: > Am 29.06.2012 23:54, schrieb Stefan Sch=E4fer: >> MF, >> >> It becomes better! >> >> I just realised that this filter is perfect to protect a receiver=20 >> like the IC706 when using a BIG antenna as the MF receive antenna. It=20 >> will be easy to build a passive circuit out of a transformer 50 Ohm=20 >> -> 18 kOhm -->Filter--> 18 kOhm -> 50 Ohm. This can be put in a small=20 >> box and then there will be no problems! I remember how the 706 and=20 >> others behave on long wires, i.e. multi-band antennas... >> >> 73, Stefan >> > Hi Stefan, > > using those filters in the antenna circuit of a rx keep in mind that=20 > the maximum input voltage is rather limited due to the high internal Q=20 > of the mechanical resonators. Here I have some 200-kHz-units from RFT=20 > with maximum input voltage of 2V resp. -10 dB relative to what ever.=20 > So be careful when using them with a seperat rx antenna! > > 73, > Tom, DK1IS --------------000303040700030005070307 Content-Type: text/html; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by relay.uni-heidelberg.de id q5UCUWWA007502 Hi Tom.

Thanks. Yes, i have the 2 V rms in mind. It was stated in the datasheet. I intend to use a series configuration of 3 antiparallel 1N4148 diodes on the input to protect the filter. At 50 Ohm, the leveles are hopefully below 2 V rms. Otherwise i will use a stepped attenuator in series of course (if clipping occurs).

73, Stefan

Am 30.06.2012 11:23, schrieb DK1IS:
Am 29.06.2012 23:54, schrieb Stefan Sch=E4fer:
MF,

It becomes better!

I just realised that this filter is perfect to protect a receiver like the IC706 when using a BIG antenna as the MF receive antenna. It will be easy to build a passive circuit out of a transformer 50 Ohm -> 18 kOhm -->Filter--> 18 kOhm -> 50 Ohm. This can be put in a small box and then there will be no problems! I remember how the 706 and others behave on long wires, i.e. multi-band antennas...

73, Stefan

Hi Stefan,

using those filters in the antenna circuit of a rx keep in mind that the maximum input voltage is rather limited due to the high internal Q of the mechanical resonators. Here I have some 200-kHz-units from RFT with maximum input voltage of 2V resp. -10 dB relative to what ever. So be careful when using them with a seperat rx antenna!

73,
Tom, DK1IS
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