X-GM-THRID: 1210402038697719081 X-Gmail-Labels: rsgb lf X-Gmail-Received: f2f866475008862d066f9dc12c0f7f3cbf5355c0 Delivered-To: daveyxm@gmail.com Received: by 10.64.249.16 with SMTP id w16cs10022qbh; Mon, 31 Jul 2006 01:10:26 -0700 (PDT) Received: by 10.49.94.20 with SMTP id w20mr1760873nfl; Mon, 31 Jul 2006 01:10:26 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mx.gmail.com with ESMTP id q28si7303428nfc.2006.07.31.01.10.24; Mon, 31 Jul 2006 01:10:26 -0700 (PDT) Received-SPF: neutral (gmail.com: 193.82.116.20 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1G7Sma-00045Z-TC for rs_out_1@blacksheep.org; Mon, 31 Jul 2006 09:05:48 +0100 Received: from [193.82.59.130] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1G7Sma-00045Q-5b for rsgb_lf_group@blacksheep.org; Mon, 31 Jul 2006 09:05:48 +0100 Received: from bay0-omc1-s24.bay0.hotmail.com ([65.54.246.96]) by relay2.thorcom.net with esmtp (Exim 4.51) id 1G7SmU-0007IF-M9 for rsgb_lf_group@blacksheep.org; Mon, 31 Jul 2006 09:05:47 +0100 Received: from BAY124-W21 ([207.46.11.184]) by bay0-omc1-s24.bay0.hotmail.com with Microsoft SMTPSVC(6.0.3790.1830); Mon, 31 Jul 2006 01:05:36 -0700 X-Originating-IP: [203.208.238.136] X-Originating-Email: [hellozerohellozero@hotmail.com] Message-ID: MIME-Version: 1.0 From: "Laurence KL1X" To: "J. Allen" Date: Mon, 31 Jul 2006 00:05:36 -0800 X-OriginalArrivalTime: 31 Jul 2006 08:05:36.0289 (UTC) FILETIME=[1AA76110:01C6B478] X-Spam-Score: 2.2 (++) X-Spam-Report: autolearn=disabled,FORGED_HOTMAIL_RCVD=2.132,HTML_40_50=0.086,HTML_MESSAGE=0.001 Content-Type: multipart/alternative; boundary="_363e2be6-5c34-4cb0-b65c-14e0be7e4fc0_" Subject: RE: LF: Antenna or transmitter tuning X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=FORGED_HOTMAIL_RCVD,HTML_20_30, 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 Status: O X-Status: X-Keywords: X-UID: 6404 --_363e2be6-5c34-4cb0-b65c-14e0be7e4fc0_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Just statiing one of things I found was the I had probs with high local fie= lds from my own transmiiter aerial affecting the oscilloscope readings. I h= ad a load of v/m as my loop running N amps was only meters from the shack -= nothing was wrong per say but I had to take care with the screen test lead= s and add an RF filter on the AC power lead - all became clear. Ao as I ram= ped up the power, save for a small change in the waveform everything looked= fine -without the filters it looked worse and worse. Prob not your prob th= ough. =20 Laurence in rainy Singapore > From: vy1ja@northwestel.net> To: rsgb_lf_group@blacksheep.org> Date: Mon,= 31 Jul 2006 06:57:27 +0000> Subject: LF: Antenna or transmitter tuning> > = Hello again Friends,> > The single FET amp which Steve lent me has been wor= king fine, but if you > remember, during tuning the antenna system would co= me up with some weird > wave shapes. The amp uses an air core output coil.= The antenna loading > coil , its matching coil and both coils in the tran= smitter's Low Pass Filter > are air core as well. So there is no iron in t= he working system.> > Remember that when the antenna was tuned, one suggest= ion was to place a > matching transformer with TV Horizontal Ferrite core i= n the circuit. When > that was done, the waveform on the scope turned to g= arbage. (high in odd > order harmonics)> > Today, the two FET amp which Sc= ott lent me was put on the air. It has a > ferrite TV output core which I = wound and even though it was placed at the > exact length of coax from the = antenna which Steve's amp had been, it 's > output waveform is badly distor= ted.> > It is important that I run the station at the maximum allowed IERP = for the > sake of proving non-interference.> > On Scott's amp, the current = and voltage waveforms are identical and in > phase, the amp runs very stabl= e at over 300 Watts input, but the waveforms > look awful. I have decided = to switch back to Steve's transmitter and > revisit both the output of Scot= t's amp and the antenna system. I am > considering winding a air core tran= sformer for it, but am unconvinced doing > so will solve the real problem.>= > I have a scopematch, and scope, an rf source capable of 18 kHz and up.>= > Any ideas on how to approach this waveform problem?> > J.> > >=20 _________________________________________________________________ Try Live.com: where your online world comes together - with news, sports, w= eather, and much more. http://www.live.com/getstarted= --_363e2be6-5c34-4cb0-b65c-14e0be7e4fc0_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable =0A= =0A= =0A= =0A= Just statiing one of things I found was the I had probs with high loc= al fields from my own transmiiter aerial affecting the oscilloscope reading= s. I had a load of v/m as my loop running N amps was only meters= from the shack - nothing was wrong per say but I had to t= ake care with the screen test leads and add an RF filter on the AC power le= ad - all became clear. Ao as I ramped up the power, save for a small change= in the waveform everything looked fine -without the filters it looked wors= e and worse. Prob not your prob though.
 
Laurence in rainy Singapore






> From: vy1ja@northwestel.net
> To: rsgb_lf_group@blacksheep.org> Date: Mon, 31 Jul 2006 06:57:27 +0000
> Subject: LF: Antenna o= r transmitter tuning
>
> Hello again Friends,
>= ;
> The single FET amp which Steve len= t me has been working fine, but if = you 
> remember, during tuning the antenna&n= bsp;system would come up with some weird = ;
> wave shapes.  The amp uses an = air core output coil.  The antenna loadi= ng 
> coil , its matching coil and = ;both coils in the transmitter's Low Pass&nbs= p;Filter 
> are air core as well.  = ;So there is no iron in the working = ;system.
>
> Remember that when the antenn= a was tuned, one suggestion was to place=  a 
> matching transformer with TV Hori= zontal Ferrite core in the circuit.  Whe= n 
> that was done, the waveform on&nbs= p;the scope turned to garbage.  (high in=  odd 
> order harmonics)
>
> Today, = the two FET amp which Scott lent me = ;was put on the air.  It has a = ;
> ferrite TV output core which I woun= d and even though it was placed at = the 
> exact length of coax from the&nb= sp;antenna which Steve's amp had been, it&nbs= p;'s 
> output waveform is badly distorted.<= BR>>
> It is important that I run t= he station at the maximum allowed IERP f= or the 
> sake of proving non-interference.<= BR>>
> On Scott's amp, the current and&n= bsp;voltage waveforms are identical and in > phase, the amp runs very stable at&nbs= p;over 300 Watts input, but the waveforms&nbs= p;
> look awful.  I have decided to&nbs= p;switch back to Steve's transmitter and 
= > revisit both the output of Scott's amp&n= bsp;and the antenna system.  I am 
&g= t; considering winding a air core transformer = ;for it, but am unconvinced doing 
> so=  will solve the real problem.
>
> I&n= bsp;have a scopematch, and scope, an rf = source capable of 18 kHz  and up.
>= ;
> Any ideas on how to approach this&= nbsp;waveform problem?
>
> J.
>
>
> <= BR>

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