Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id w6ACWwmP030238 for ; Tue, 10 Jul 2018 14:33:01 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1fcrkX-0001mC-PM for rs_out_1@blacksheep.org; Tue, 10 Jul 2018 13:28:09 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1fcrkQ-0001m3-8g for rsgb_lf_group@blacksheep.org; Tue, 10 Jul 2018 13:28:02 +0100 Received: from mout01.posteo.de ([185.67.36.65]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91_59-0488984) (envelope-from ) id 1fcrkN-00018G-Rt for rsgb_lf_group@blacksheep.org; Tue, 10 Jul 2018 13:28:01 +0100 Received: from submission (posteo.de [89.146.220.130]) by mout01.posteo.de (Postfix) with ESMTPS id 2511620F2F for ; Tue, 10 Jul 2018 14:27:57 +0200 (CEST) X-DKIM-Result: Domain=posteo.de Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.de; s=2017; t=1531225678; bh=6vTT86RkapYkFUjuCvCKENCueBrssnG8op/ZHuu1dfU=; h=Date:From:To:Subject:From; b=N3KAM+hxlnyyNHGvtgs1n59NvOKAKo8f8W9iv6v691RtBR2pZgarbRk/kg0P9IZd6 TJz4S7dDM/jLlFyBAbLs2pVbYV/OWrKbXouVnHBritWgv8v/Y4IyeZGx9TE5NYHE8v D5Vb6/GSkdMM0M1hcJjnh1/GCsPDeqt+1jIW8CQo9nw//yKkLN29L1OL+3mp1RkVl9 +uUCuGdqBpiKG9YGTIURUZGyzhTRBOyleA8bfh6jOr2rHvFJXXAqQyYLRyWuVLNe/F F7Ld50uDT+Ch8/g8kmM46luVGd/KkPWsxAb6SWvM3DNg3JWOS2GzeMWuUUmMNsTLTY fNwjrYNnUq/4w== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 41Q1gb2XVxz9rxT for ; Tue, 10 Jul 2018 14:27:54 +0200 (CEST) Message-ID: <5B44A64A.1070307@posteo.de> Date: Tue, 10 Jul 2018 14:27:54 +0200 From: DK7FC 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: <09a39510-37a4-06dc-5fc8-05fe24d4e681@n1bug.com> In-Reply-To: <09a39510-37a4-06dc-5fc8-05fe24d4e681@n1bug.com> X-Spam-Score: -2.3 (--) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see @@CONTACT_ADDRESS@@ for details. Content preview: Hi Paul, It strongly depends on how your front end is designed. Am 10.07.2018 14:04, schrieb N1BUG: > Now I have a pair of back to back 1N4148 diodes across the receiver > front end but I don't think this offers real protection because they > allow too high voltage before conducting. I don't think so. They work until several 100 MHz so they are extremely fast. Further you can switch a small R (depending on the design) in front of the diodes. This also builds a RC lowpass which can help to rise the performance. [...] Content analysis details: (-2.3 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, medium trust [185.67.36.65 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: e90dcb17768c7e768f13e0721cc1c0c7 Subject: Re: LF: Receiver protection Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit 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=none 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 Hi Paul, It strongly depends on how your front end is designed. Am 10.07.2018 14:04, schrieb N1BUG: > Now I have a pair of back to back 1N4148 diodes across the receiver > front end but I don't think this offers real protection because they > allow too high voltage before conducting. I don't think so. They work until several 100 MHz so they are extremely fast. Further you can switch a small R (depending on the design) in front of the diodes. This also builds a RC lowpass which can help to rise the performance. I'm also using 1N4148 diodes but not back to back, rather one against ground, the other against +, while the center is at V/2. > Also there is a preamp > after the didoes which can bring the RF to dangerous levels! > How? The output voltage of the preamp can't be higher than the supply voltage. 73, Stefan