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 w07HVQx0018855 for ; Sun, 7 Jan 2018 18:31:27 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1eYEiX-00022V-Hi for rs_out_1@blacksheep.org; Sun, 07 Jan 2018 17:26:41 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1eYEiX-00022M-3K for rsgb_lf_group@blacksheep.org; Sun, 07 Jan 2018 17:26:41 +0000 Received: from mout.perfora.net ([74.208.4.194]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1eYEiT-0007Ek-JG for rsgb_lf_group@blacksheep.org; Sun, 07 Jan 2018 17:26:39 +0000 Received: from [192.168.1.127] ([72.224.254.201]) by mrelay.perfora.net (mreueus003 [74.208.5.2]) with ESMTPA (Nemesis) id 0MNs0D-1eVjsX4055-007UID for ; Sun, 07 Jan 2018 18:26:35 +0100 To: "rsgb_lf_group@blacksheep.org" From: N1BUG Message-ID: <923db48e-ca8e-67d5-e70d-3c9695277b97@n1bug.com> Date: Sun, 7 Jan 2018 12:26:33 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 Content-Language: en-US X-Provags-ID: V03:K0:PfrwYyvI/vqy/CaVmp6a3qqfKD0U35g+fIjpXKlAC0UBV7XSuiB 7L0ow1n3vC9ywkQqLMml0waCbfKdhRxvMnxtq60pCAx/htoN3htfzaYgnV1v2ZAStnReP6f U9xFBNgWpLa4RH3yy3UAQm8/qwdxLAU1awQc/hYI20q7Mi/Et+VfoQckjtUWirTt5pVY/jW i6ToMUNNOoL0idz1o4Wxg== X-UI-Out-Filterresults: notjunk:1;V01:K0:daCwNpRCrfs=:l407kO5qht/qlLv3e3bCwu 81iWYWxrgT5xf9d+KgSEP+Xp5scfhFkba4IcSR42xsyhof3P4cLjBpLtllPwq6Cry+3g8NML6 U8g5q4cfj/2OkPN3YPmtV5qmEn3G/c4l3VGeM05zqIhfph17KzOvS5azMr/ei/c/wAyMJmLcF 7ELdv6I8Kke0isPSywnbXnfQLGs9C9Aes5bvGNsz6xGoDRwTPCKMiHlYBXf6JMQXQYGnRkTCM OcaBjuO7J0+0OfrgH2hfSx56ousOBmOXCEWd3FBfMEm9VRZdDW8UfmEHCe1JYhQYwdrfg8xhc HzIjj72DMCyJ1+6qlNHt0bv5TNpzJ6hLtqdDhFb+0pUzcNvIhqfEOMMlIsASZy0ZCGyRzMQz9 wcyCLbF1i/J9zKUjF3lxlM1uOiuFZsgIOMp453XPbQDBUiyNV0MMWWnBynj6bZSL1TTyawv/N 0Mslg6gnPH6DT4fQzgKX3F/1tvjzz8Orp39vF3k+iFURFL3bv2YK1MVZ6eg+1Wd8Hfmfu1R5s inkrbipvUw1l1JDHwlNLOHID6Ml99QJAlMbRXjTt5ZetaN82ef8AePX1H2bI1n7PP6lZYDh4M A9mFNaHCi7NtLndrooVpvXR+lQF12iCWtojxRZSUBvOhdNuHEnvQx4AV9zEGl/CKmEXaeTXcY lSK38xgyGVm5OlA98zXQcIWFMh4RIaCeqE4dZ4X+k7KgpA97s1QjbsK22oNnVdLPjC/r1WbCU 7Lk+sy/VXNFKEXmzIeswRUS+RHh6eC/+N9VfujvOq3ph7lsjV7J8V2NBKtA= X-Spam-Score: 0.0 (/) 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 the administrator of that system for details. Content preview: http://n1bug.com/n1debug/ASB_LF_Amp-20171223.jpg Recall that last week I had increased turns on the output transformer from 3x5 to 3x10. That reduced heating of the FET but did not help to stabilize the PA. It would put 12 to 14W into the antenna before oscillation started. [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- X-Scan-Signature: b77892ad90d0261eaf071f4f6cf31464 Subject: LF: Progress? with the PA 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=TO_ADDRESS_EQ_REAL 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 http://n1bug.com/n1debug/ASB_LF_Amp-20171223.jpg Recall that last week I had increased turns on the output transformer from 3x5 to 3x10. That reduced heating of the FET but did not help to stabilize the PA. It would put 12 to 14W into the antenna before oscillation started. Today I changed it to 4x10 turns so it is now a 16:1 transformer. This has made a big change! The PA will now put more than 30 watts into the antenna before oscillation starts with 13V on it. For the first time I noticed some slight warming of the transformer. I think it is the core heating up, not the wire. If I put 19V on it, I briefly see almost 50 watts into the antenna but the transformer becomes hot very quickly and within just 3 or 4 seconds, power begins to drop rapidly. At this point I guess either: The core is not suitable material or not big enough... or Maybe it needs fewer turns (but this may lead to too much heat in the FET again?) At 30W output with 13V, that FET is already running quite warm with 4x10 turns. At least I finally found something that makes a change! 73, Paul N1BUG