Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, HTML_MESSAGE,RCVD_IN_DNSWL_MED,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: : mailn 1480; Body=2 Fuz1=2 Fuz2=2 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u1) with ESMTP id v3FDHHFB023595 for ; Sat, 15 Apr 2017 15:17:18 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1czNWx-0005uR-Kx for rs_out_1@blacksheep.org; Sat, 15 Apr 2017 14:14:23 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1czNWx-0005uF-2E for rsgb_lf_group@blacksheep.org; Sat, 15 Apr 2017 14:14:23 +0100 Received: from smtpout5.wanadoo.co.uk ([80.12.242.80] helo=smtpout.wanadoo.co.uk) by relay1.thorcom.net with esmtp (Exim 4.89) (envelope-from ) id 1czNWs-0005Xi-Tk for rsgb_lf_group@blacksheep.org; Sat, 15 Apr 2017 14:14:21 +0100 Received: from AGB ([95.150.163.2]) by mwinf5d68 with ME id 8dEH1v00F03Qyhb03dEH3q; Sat, 15 Apr 2017 15:14:18 +0200 X-ME-Helo: AGB X-ME-Date: Sat, 15 Apr 2017 15:14:18 +0200 X-ME-IP: 95.150.163.2 Message-ID: <20623F28F103422F8F6F961B025E44C1@AGB> From: "Graham" To: References: <272136023.20170415133220@gmail.com> In-Reply-To: <272136023.20170415133220@gmail.com> Date: Sat, 15 Apr 2017 14:14:17 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 X-Antivirus: Avast (VPS 170415-0, 15/04/2017), Outbound message X-Antivirus-Status: Clean X-Scan-Signature: 78d05de8a7db6bc9dc86a4eec49da9b7 Subject: Re: LF: Poor aerial connection affecting gate waveforms?? Content-Type: multipart/alternative; boundary="----=_NextPart_000_0055_01D2B5F2.91529FF0" 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-Scanned-By: MIMEDefang 2.75 Status: O X-Status: X-Keywords: X-UID: 11315 This is a multi-part message in MIME format. ------=_NextPart_000_0055_01D2B5F2.91529FF0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Chris, I assume , due to the Q any small variation , will move the tune point= about , but looking in the data base , Signals , better last night to= sv8 than the previous night , and may be up 1 db at pa7 , not to say= the noise was less , but at -10 db that level will be much higher = than the local noise level , should be a reliable indication How important are the wave forms ? 73-G, 2017-04-15 06:15:22 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -43 Op32__~43dB= 2017-04-15 05:25:22 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -44 Op32__~44dB= 2017-04-15 04:35:22 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -34 Op32_||||||= ||_~34dB 2017-04-15 03:45:20 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -30 Op32_||||||= ||||||||_~31dB 2017-04-15 02:55:22 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -33 Op32_||||||= ||||_~33dB 2017-04-15 02:05:20 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -34 Op32_||||||= ||_~34dB 2017-04-15 01:15:20 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -32 Op32_||||||= ||||||_~32dB 2017-04-14 23:35:23 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -42 Op32__~42dB= 2017-04-14 22:45:21 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -33 Op32_||||||= ||||_~33dB 2017-04-14 21:55:22 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -38 Op32__~39dB= 2017-04-14 06:05:21 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -36 Op32_||||_~= 36dB 2017-04-14 04:25:22 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -44 Op32__~44dB= 2017-04-14 03:35:21 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -38 Op32__~38dB= 2017-04-14 02:45:21 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -35 Op32_||||_~= 36dB 2017-04-14 01:55:21 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -36 Op32_||||_~= 36dB 2017-04-14 01:05:21 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -38 Op32__~38dB= 2017-04-13 23:25:22 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -40 Op32__~40dB= 2017-04-13 22:35:22 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -41 Op32__~41dB= very similar at PA7EV , may be + 1 dB 2017-04-15 10:25:20 2E0ILY IO82QV PA7EY JO22JJ 503 136 -13 Op32_||= ||||||||||||||||||||||||||||||||||||||||||||||||_~13dB 2017-04-15 09:35:21 2E0ILY IO82QV PA7EY JO22JJ 503 136 -7 Op32_|||= |||||||||||||||||||||||||||||||||||||||||||||||||||||||||_~8dB 2017-04-15 08:45:20 2E0ILY IO82QV PA7EY JO22JJ 503 136 -8 Op32_|||= |||||||||||||||||||||||||||||||||||||||||||||||||||||||_~9dB 2017-04-15 07:55:20 2E0ILY IO82QV PA7EY JO22JJ 503 136 -11 Op32_||= ||||||||||||||||||||||||||||||||||||||||||||||||||||_~11dB 2017-04-15 07:05:21 2E0ILY IO82QV PA7EY JO22JJ 503 136 -10 Op32_||= ||||||||||||||||||||||||||||||||||||||||||||||||||||_~11dB 2017-04-15 06:15:19 2E0ILY IO82QV PA7EY JO22JJ 503 136 -12 Op32_||= ||||||||||||||||||||||||||||||||||||||||||||||||_~13dB 2017-04-15 05:25:20 2E0ILY IO82QV PA7EY JO22JJ 503 136 -9 Op32_|||= |||||||||||||||||||||||||||||||||||||||||||||||||||||_~10dB 2017-04-15 03:45:19 2E0ILY IO82QV PA7EY JO22JJ 503 136 -11 Op32_||= ||||||||||||||||||||||||||||||||||||||||||||||||||||_~11dB 2017-04-15 02:55:21 2E0ILY IO82QV PA7EY JO22JJ 503 136 -11 Op32_||= ||||||||||||||||||||||||||||||||||||||||||||||||||||_~11dB 2017-04-15 02:05:21 2E0ILY IO82QV PA7EY JO22JJ 503 136 -10 Op32_||= ||||||||||||||||||||||||||||||||||||||||||||||||||||||_~10dB 2017-04-15 01:15:20 2E0ILY IO82QV PA7EY JO22JJ 503 136 -9 Op32_|||= |||||||||||||||||||||||||||||||||||||||||||||||||||||||_~9dB 2017-04-15 00:25:21 2E0ILY IO82QV PA7EY JO22JJ 503 136 -9 Op32_|||= |||||||||||||||||||||||||||||||||||||||||||||||||||||_~10dB 2017-04-14 23:35:20 2E0ILY IO82QV PA7EY JO22JJ 503 136 -12 Op32_||= ||||||||||||||||||||||||||||||||||||||||||||||||_~13dB 2017-04-14 22:45:21 2E0ILY IO82QV PA7EY JO22JJ 503 136 -9 Op32_|||= |||||||||||||||||||||||||||||||||||||||||||||||||||||_~10dB 2017-04-14 21:55:20 2E0ILY IO82QV PA7EY JO22JJ 503 136 -9 Op32_|||= |||||||||||||||||||||||||||||||||||||||||||||||||||||_~10dB 2017-04-14 10:15:20 2E0ILY IO82QV PA7EY JO22JJ 503 136 -11 Op32_||= ||||||||||||||||||||||||||||||||||||||||||||||||||_~12dB 2017-04-14 09:25:21 2E0ILY IO82QV PA7EY JO22JJ 503 136 -9 Op32_|||= |||||||||||||||||||||||||||||||||||||||||||||||||||||||_~9dB 2017-04-14 08:35:20 2E0ILY IO82QV PA7EY JO22JJ 503 136 -10 Op32_||= ||||||||||||||||||||||||||||||||||||||||||||||||||||||_~10dB 2017-04-14 07:45:20 2E0ILY IO82QV PA7EY JO22JJ 503 136 -10 Op32_||= ||||||||||||||||||||||||||||||||||||||||||||||||||||_~11dB 2017-04-14 06:55:21 2E0ILY IO82QV PA7EY JO22JJ 503 136 -9 Op32_|||= |||||||||||||||||||||||||||||||||||||||||||||||||||||_~10dB 2017-04-14 06:05:19 2E0ILY IO82QV PA7EY JO22JJ 503 136 -9 Op32_|||= |||||||||||||||||||||||||||||||||||||||||||||||||||||_~10dB 2017-04-14 05:15:22 2E0ILY IO82QV PA7EY JO22JJ 503 136 -8 Op32_|||= |||||||||||||||||||||||||||||||||||||||||||||||||||||||||_~8dB 2017-04-14 04:25:19 2E0ILY IO82QV PA7EY JO22JJ 503 136 -10 Op32_||= ||||||||||||||||||||||||||||||||||||||||||||||||||||_~11dB 2017-04-14 03:35:19 2E0ILY IO82QV PA7EY JO22JJ 503 136 -13 Op32_||= ||||||||||||||||||||||||||||||||||||||||||||||||_~13dB 2017-04-14 02:45:19 2E0ILY IO82QV PA7EY JO22JJ 503 136 -17 Op32_||= ||||||||||||||||||||||||||||||||||||||||_~17dB 2017-04-14 01:55:20 2E0ILY IO82QV PA7EY JO22JJ 503 136 -13 Op32_||= ||||||||||||||||||||||||||||||||||||||||||||||_~14dB 2017-04-14 01:05:20 2E0ILY IO82QV PA7EY JO22JJ 503 136 -13 Op32_||= ||||||||||||||||||||||||||||||||||||||||||||||_~14dB 2017-04-14 00:15:21 2E0ILY IO82QV PA7EY JO22JJ 503 136 -13 Op32_||= ||||||||||||||||||||||||||||||||||||||||||||||||_~13dB 2017-04-13 23:25:21 2E0ILY IO82QV PA7EY JO22JJ 503 136 -13 Op32_||= ||||||||||||||||||||||||||||||||||||||||||||||||_~13dB 2017-04-13 22:35:20 2E0ILY IO82QV PA7EY JO22JJ 503 136 -9 Op32_|||= |||||||||||||||||||||||||||||||||||||||||||||||||||||||_~9dB 2017-04-13 21:45:20 2E0ILY IO82QV PA7EY JO22JJ 503 136 -14 Op32_||= ||||||||||||||||||||||||||||||||||||||||||||_~15dB -------------------------------------------------- From: "Chris Wilson" Sent: Saturday, April 15, 2017 1:32 PM To: Subject: LF: Poor aerial connection affecting gate waveforms?? > Hello LF'ers, > > A very happy Easter to everyone! > > I have a tech question tthat I am sure you more experienced > operators can answer. yesterday I mowed the lawn and found some > of my temporary earth leads connecting a square of ground wires > with 2 diaganols to 8 foot ground posts had been eaten by > rabbits and were disconnected. i re-made them and today will > finish them by blting soldered eyelt tags to the pists with > stainless bolts and covering them well with Galvafroid paint. > When I finished I had a meal and started the night's TX on > 137.550 as normal. I saw a very poor gate and drain waveform > from my W1VD style amp, the previous night they looked normal > 9and OK to me...). I assumed it was to do with my fiddling with > the grounds. My Scopematch box also showed a slight impedance > mismatch and a slight resonance mismatch. I attended to both > with the tapped matching coil outside and the variometer in the > loading coil, but the waveforms on gate and drain remained very > spiky. I risked running and signal reports seemed OK, if not as > good as the night before, using WSPR2 and OPERA. > > This morning i investigated properly and put my 500W dummy load > after the LPF bank in the shack and the gate and drain waveforms > were back to normal. I then put it outside after the matching > transformer, and although there was an impedance mismatch the > gates and drains wave forms were still fine. So i moved to the > loading coil. This has had reapirs to the lead to vertical > section of the aerial, where it goes up from the coils housing > in a big wheelie bin to where the ladder line vertical secion > goes up to meet the horizontal loop top hat. it has two "choc > bloc" screw connectors joing a new piece of wire where the old > one shorted out and burnt the insulation. They LOOKED fine, but > i decided to remove them and properly solder in the repair > section and use adhesive lined shrink tube to seal the joints. > > Hey, gates and drains now back to normal. I had also noticed the > Scopemeter was showing a peak og 13.6V when the gate and drain > waveforms were spiky, and now that was back to the normal 12.4 > or so volts. > > Finally.my question. Why would a poor or high resistance > connection on the vertical section of the antenna affect the > gate waveforms? I think I can see why the drains were affected, > but why the gates, and why the higher volts on the Scopematch > traces? Thanks, I like to try and find out WHY things have > happened, even after fixing them, so I appreciate any > instruction here. I attach links to the normal gate and drain > waveforms and a second link to how they were last night. Amp is > voltage mode Class D. > > Normal: http://www.gatesgarth.com/normal.jpg > > Last night : http://www.gatesgarth.com/spiky.jpg > > -- > Best regards, > Chris mailto:dead_fets@gmail.com > > --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ------=_NextPart_000_0055_01D2B5F2.91529FF0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Chris,
 
I assume , due to the  Q any small  variation , will  m= ove the  tune  point  about , but  looking  in the&nbs= p; data base , Signals , better last night  to  sv8 than  the&n= bsp; previous night , and  may be up  1 db at pa7  , not to say the  noise was less , but  at  -10 db  that level = will  be  much  higher  than the  local noise leve= l , should be a  reliable  indication
 
How important  are the  wave forms ?
 
73-G,

2017-04-15 06:15:22 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 1= 36 -43 Op32__~43dB
2017-04-15 05:25:22 2E0ILY IO82QV SV8RV-10 KM07KS 2.469= 136 -44 Op32__~44dB
2017-04-15 04:35:22 2E0ILY IO82QV SV8RV-10 KM07KS 2.469= 136 -34 Op32_||||||||_~34dB
2017-04-15 03:45:20 2E0ILY IO82QV SV8RV-10 KM07= KS 2.469 136 -30 Op32_||||||||||||||_~31dB
2017-04-15 02:55:22 2E0ILY IO82= QV SV8RV-10 KM07KS 2.469 136 -33 Op32_||||||||||_~33dB
2017-04-15 02:05:20= 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -34 Op32_||||||||_~34dB
2017-04= -15 01:15:20 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -32 Op32_||||||||||||_~32d= B
2017-04-14 23:35:23 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -42 Op32__~= 42dB
2017-04-14 22:45:21 2E0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -33 Op32_||||||||||_~33dB
2017-04-14 21:55:22 2E0ILY IO82QV SV8RV-10 KM07KS= 2.469 136 -38 Op32__~39dB
2017-04-14 06:05:21 2E0ILY IO82QV SV8RV-10 KM= 07KS 2.469 136 -36 Op32_||||_~36dB
2017-04-14 04:25:22 2E0ILY IO82QV SV8RV-1= 0 KM07KS 2.469 136 -44 Op32__~44dB
2017-04-14 03:35:21 2E0ILY IO82QV SV8R= V-10 KM07KS 2.469 136 -38 Op32__~38dB
2017-04-14 02:45:21 2E0ILY IO82QV SV8R= V-10 KM07KS 2.469 136 -35 Op32_||||_~36dB
2017-04-14 01:55:21 2E0ILY IO82QV = SV8RV-10 KM07KS 2.469 136 -36 Op32_||||_~36dB
2017-04-14 01:05:21 2E0IL= Y IO82QV SV8RV-10 KM07KS 2.469 136 -38 Op32__~38dB
2017-04-13 23:25:22 2E= 0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -40 Op32__~40dB
2017-04-13 22:35:22 2E= 0ILY IO82QV SV8RV-10 KM07KS 2.469 136 -41 Op32__~41dB
 
very similar  at PA7EV , may be  + 1 dB 

 2017-04-15 10:25:20  2E0ILY  IO82QV  PA7EY  JO22JJ  503  136  -13  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||_~13dB  2017-04-15 09:35:21  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -7  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||_~8d= B 
 2017-04-15 08:45:20  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -8  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||||||_~9dB&= nbsp;
 2017-04-15 07:55:20  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -11  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||_~11dB&nbs= p;
 2017-04-15 07:05:21  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -10  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||_~11dB&nbs= p;
 2017-04-15 06:15:19  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -12  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||_~13dB  2017-04-15 05:25:20  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -9  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||||_~10dB&n= bsp;
 2017-04-15 03:45:19  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -11  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||_~11dB&nbs= p;
 2017-04-15 02:55:21  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -11  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||_~11dB&nbs= p;
 2017-04-15 02:05:21  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -10  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||||_~10dB&n= bsp;
 2017-04-15 01:15:20  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -9  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||||||_~9dB&= nbsp;
 2017-04-15 00:25:21  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -9  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||||_~10dB&n= bsp;
 2017-04-14 23:35:20  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -12  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||_~13dB  2017-04-14 22:45:21  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -9  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||||_~10dB&n= bsp;
 2017-04-14 21:55:20  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -9  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||||_~10dB&n= bsp;
 2017-04-14 10:15:20  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -11  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||_~12dB =
 2017-04-14 09:25:21  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -9  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||||||_~9dB&= nbsp;
 2017-04-14 08:35:20  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -10  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||||_~10dB&n= bsp;
 2017-04-14 07:45:20  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -10  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||_~11dB&nbs= p;
 2017-04-14 06:55:21  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -9  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||||_~10dB&n= bsp;
 2017-04-14 06:05:19  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -9  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||||_~10dB&n= bsp;
 2017-04-14 05:15:22  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -8  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||_~8d= B 
 2017-04-14 04:25:19  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -10  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||_~11dB&nbs= p;
 2017-04-14 03:35:19  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -13  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||_~13dB  2017-04-14 02:45:19  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -17  Op32_||||||||||||||||||||||||||||||||||||||||||_~17dB 
 = 2017-04-14 01:55:20  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -13  Op32_||||||||||||||||||||||||||||||||||||||||||||||||_~14dB 
=  2017-04-14 01:05:20  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -13  Op32_||||||||||||||||||||||||||||||||||||||||||||||||_~14dB 
=  2017-04-14 00:15:21  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -13  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||_~13dB  2017-04-13 23:25:21  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -13  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||_~13dB  2017-04-13 22:35:20  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -9  Op32_||||||||||||||||||||||||||||||||||||||||||||||||||||||||||_~9dB&= nbsp;
 2017-04-13 21:45:20  2E0ILY  IO82QV  PA7EY  JO22JJ  503  = ;136  -14  Op32_||||||||||||||||||||||||||||||||||||||||||||||_~15dB


=
--------------------------------------------------
From: "Chris Wilson" <dead.fets@gmail.com>
Sent: Saturday, April 15, 201= 7 1:32 PM
To: <rsgb_lf_group@blacksheep.org>
Subject: LF: Poor ae= rial connection affecting gate waveforms??

> Hello LF'ers,
>
>      A very happy Easter to everyone!
= >
>      I  have  a  tech = ; question  tthat I am sure you more experienced
>      operators  can answe= r. yesterday I mowed the lawn and found some
>    &n= bsp; of  my temporary earth leads connecting a square of ground wires
>      with  2  diaganols&nb= sp; to  8  foot  ground  posts had been eaten by
>      rabbits  and  were = disconnected.  i re-made them and today will
>      finish  them  by = blting  soldered  eyelt tags to the pists with
>      stainless  bolts  and&= nbsp; covering them well with Galvafroid paint.
>    &n= bsp; When  I  finished  I  had  a  meal and starte= d the night's TX on
>      137.550  as  = normal.  I  saw a very poor gate and drain waveform
>      from  my  W1VD&nbs= p; style amp, the previous night they looked normal
>      9and  OK to me...). I ass= umed it was to do with my fiddling with
>      the  grounds.  My  Scopematch box also showed a slight impedance
>      mismatch  and  a&= nbsp; slight  resonance mismatch. I attended to both
>      with  the tapped matching c= oil outside and the variometer in the
>      loading  coil, but the waveforms on gate and drain remained very
>      spiky.  I risked running an= d signal reports seemed OK, if not as
>      g= ood as the night before, using WSPR2 and OPERA.
>
>      This  morning i investigated properly and put my 500W dummy load
>      a= fter the LPF bank in the shack and the gate and drain waveforms
>      were  back  to&nb= sp; normal. I then put it outside after the matching
>      transformer,  and = although  there was an impedance mismatch the
>      gates  and  drains wave= forms were still fine. So i moved to the
>    &nb= sp; loading  coil.  This  has  had  reapirs  to t= he lead to vertical
>      section  of&nbs= p; the aerial, where it goes up from the coils housing
>      in  a  big  wh= eelie bin to where the ladder line vertical secion
>      goes  up  to  m= eet the horizontal loop top hat. it has two "choc
>      bloc"  screw  connect= ors joing a new piece of wire where the old
>    &nbs= p; one  shorted out and burnt the insulation. They LOOKED fine, but
>      i  decided  to  remove  them  and  properly solder in the repair
>      section and use adhesive lined= shrink tube to seal the joints.
>
>    &nb= sp; Hey, gates and drains now back to normal. I had also noticed the
>      Scopemeter  was  showin= g a peak og 13.6V when the gate and drain
>     = waveforms  were  spiky, and now that was back to the normal 12.4
>      or so volts.
>
>      Finally.my  question.  Why  would  a  poor  or  high  resistance
>      connection  on  = the  vertical  section of the antenna affect the
>      gate  waveforms? I think I c= an see why the drains were affected,
>      but  why  the  gates, and why the higher volts on the Scopematch
>      traces?    = Thanks,  I  like  to try and find out WHY things have
>      happened,   even   after   fixing  them,  so  I = ; appreciate  any
>      instruction = ; here.  I  attach links to the normal gate and drain
>      waveforms  and a second li= nk to how they were last night. Amp is
>      volt= age mode Class D.
>
>      Normal:  = http://www.gatesgarth.com/normal.jpg
>
>      Last night : http://www.gatesgarth.com/spiky.jpg
>
> --
> Best regards,
> Chris           &nbs= p;            &= nbsp; mailto:dead_fets@gmail.com
>
>

Virus-= free. www.avast.com
------=_NextPart_000_0055_01D2B5F2.91529FF0--