Return-Path: Received: from mtain-dj07.r1000.mx.aol.com (mtain-dj07.r1000.mail.aol.com [172.19.187.143]) by air-db07.mail.aol.com (v129.4) with ESMTP id MAILINDB073-86494c962dfd1c8; Sun, 19 Sep 2010 11:36:29 -0400 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dj07.r1000.mx.aol.com (Internet Inbound) with ESMTP id 126DC38000095; Sun, 19 Sep 2010 11:36:27 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OxLux-0000iN-0v for rs_out_1@blacksheep.org; Sun, 19 Sep 2010 16:35:03 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OxLum-0000i8-F9 for rsgb_lf_group@blacksheep.org; Sun, 19 Sep 2010 16:34:52 +0100 Received: from mail-iw0-f171.google.com ([209.85.214.171]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OxLul-0004fR-1N for rsgb_lf_group@blacksheep.org; Sun, 19 Sep 2010 16:34:53 +0100 Received: by iwn42 with SMTP id 42so4209002iwn.16 for ; Sun, 19 Sep 2010 08:34:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:content-type; bh=VgoGa90fzi9im4UAFUBQTKY6Q/Dxyn1eJyHmgCeWalo=; b=qmqrD9dpPylLSgfwalPQynnjcG6LRfyrg6jxXjeDhlyN/xMrH3imozxMY/kf9W8BPD YA9ZGKl0OUJs0tfgC/NI1jTMvsI8JLdNmjKSoLXAQs4wI+/EP1IN8JjfTIRV2G2HuUf7 LgvampoxW/kFd+5wofHL4Q0rNIb6ERkUOAWL8= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=Wfs+DfaCQK146kJlzlxBhNzlwglziXFP7cSTiWaAhKO1rJtfkwRjAtqFy9/ow9mEvL C5rVmYz29fn7w6eSPSnpRdPE5SucvzyXi3FlVlKB/Vk92oQF2bjSixb6KDmHpy0OGFZk mQdPzlQyTX9FCr8ZmLoH+uk3oUcj+HgsvzIFg= MIME-Version: 1.0 Received: by 10.231.14.8 with SMTP id e8mr8744281iba.16.1284910489073; Sun, 19 Sep 2010 08:34:49 -0700 (PDT) Received: by 10.231.145.145 with HTTP; Sun, 19 Sep 2010 08:34:48 -0700 (PDT) In-Reply-To: <72058F817D724A7D83DC9E4758482D12@AGB> References: <4C95EEA4.20904@iup.uni-heidelberg.de> <72058F817D724A7D83DC9E4758482D12@AGB> Date: Sun, 19 Sep 2010 16:34:48 +0100 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: WSPR Beacon -RIP Content-Type: multipart/alternative; boundary=0003255765ae45026904909e895e X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.8 required=5.0 tests=HTML_30_40,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-AUTHENTICATION: mail_rly_antispam_dkim-d267.1 ; domain : googlemail.com DKIM : pass x-aol-sid: 3039cdbc9d0c4c962dfb0d74 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none X-Mailer: Unknown (No Version) --0003255765ae45026904909e895e Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable I think the metal tape is the answer. It was never there to serve any electrical purpose, but seemed ideal at the time to waterproof the gaps in the rather crude press fit construction It was the stuff designed for sealing heating and air conditioning ducts, plastic backed so definitely= did not make good electrical contact wher eit overlapped. Right at the base where the fire was at its fiercest, the residual tape is close, and was probably touching, the thick copper earthing wire that went around inside. Its quite likely it started sparking at this point and once the plastic wa= s charred, it just started absorbing more energy. Not sure what the plastic material is, but the fumes, though potent, weren= 't too bad and the smell was something like burnt polycarbonate. For the replacement, think I'll return to the plastic dustbin idea that served so well before, but make a better support inside with easier access to the variometer Andy www.g4jnt.com On 19 September 2010 13:03, Graham wrote: > Sorry to see that Andy, > > The metal tape looks suspicious, damage very intense at the lower far > corner , shelf is most probably heat damage from the fire as under the > coil looks intact ? > > I for one will be having a quick look in the shed, round the 500 atu > make sure nothing is 'too' close > > G. > > > > *From:* Andy Talbot > *Sent:* Sunday, September 19, 2010 12:22 PM > *To:* rsgb_lf_group@blacksheep.org ; jfell@tesco.net ; Julian@ygf.org.uk > *Subject:* Re: LF: WSPR Beacon -RIP > > http://www.g4jnt.com/QRO_LF_DoesThis.JPG > http://www.g4jnt.com/Melted_ATU_Cabin.JPG > > Not sure what started burning, but it was in the bottom corner by the lo= ok > of things which is well away from the high voltage stuff at the top. > > The system ran for years using a plastic dustbin as the coil housing, ev= en > at 800 Watts occasionally. But from the way the shelf has melted, it lo= oks > as if the plastic used in those B+Q sheds absorbs RF. Pity, it was goi= ng > to house HF ATU > > > > Andy > www.g4jnt.com > > > 2010/9/19 Stefan Sch=E4fer > >> Andy, >> >> QRO can be an exciting adventure! :-) >> >> 73, GL, >> >> Stefan >> >> >> >> Am 19.09.2010 12:54, schrieb Andy Talbot: >> >> Well, it was nice while it lasted. Went downstairs and smelt smoke. >> Heard a crackling noise coming from the plastic "shed" housing the ATU= . >> Opened the door, saw flames and melted plastic. >> >> Two buckets of water before they were extinguished - plastic B+Q sheds >> burn very well >> >> Goodbye antenna tuning cabin :-( >> >> The loading coil and antenna survived. My credibiilty didn't :-( >> >> Pictures will follow >> >> Andy >> www.g4jnt.com >> >> >> On 19 September 2010 11:44, Andy Talbot wrot= e: >> >>> Sinece theere were no reports of my QRP WSPR beacon last night two >>> conclusions can be drawn : >>> >>> a) No One was listening >>> b) Its too weak. >>> >>> To resolve a) ...... ?? Not a lot I can do apart from post this >>> message :-( >>> >>> But to resolve b), I've now fired up the big switchmode PA >>> http://www.g4jnt.com/137tx.pdf >>> Generating about 600 Watts this will increase ERP into the region of >>> 17dBm >>> (The WSPR message says 13dBm, but its lying. I've already run up and >>> downstairs with the PIC programmer, and don't want to do it again) >>> >>> >>> >>> Andy >>> www.g4jnt.com >>> >> >> > > > --0003255765ae45026904909e895e Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
I think the metal tape is the answer.=A0=A0 It was never there to ser= ve any electrical purpose, but seemed ideal at the time to waterproof the= gaps in the rather crude press fit construction=A0=A0 It was the stuff de= signed for sealing heating and air conditioning ducts, plastic backed so= definitely did not make good electrical contact wher eit overlapped.=A0= Right at the base where the fire was at its fiercest, the residual tape= is close, and was probably touching, the thick copper earthing wire that= =A0went around inside.=A0=A0 Its quite likely it started sparking at this= point and once the plastic was charred, it just started absorbing more en= ergy.
=A0
Not sure what the plastic material is, but the fumes, though potent,= weren't too bad and the smell was something like burnt polycarbonate.=
=A0
For the replacement, think I'll return to the plastic dustbin ide= a that served so well before, but make a better support inside with easier= access to the variometer
On 19 September 2010 13:03, Graham <g8fzk@g8fzk.fsnet.co.= uk> wrote:
Sorry to see=A0 that Andy,
=A0
The metal=A0 tape looks suspicious,= =A0damage =A0very intense at the=A0lower =A0far=A0 corner , shelf is most= probably heat damage=A0 from the=A0 fire as under the=A0 coil looks intac= t ?
=A0
I for=A0 one will=A0 be having a quic= k look in the shed, round the=A0 500 atu=A0 make=A0 sure nothing is 't= oo' close
=A0
G.
=A0
=A0

Sent: Sunday, September 19, 2010 12:22 PM
Subject: Re: LF: WSPR Beacon -RIP

Not sure what started burning, but it was in the bottom corner by the= look of things which is well away from the=A0high voltage stuff at the to= p.=A0=A0
=A0
The system ran for years using a plastic dustbin as the coil housing,= even at 800 Watts occasionally.=A0 But from the way the shelf has melted,= it looks as if the plastic used in those B+Q sheds absorbs RF.=A0=A0 Pity= , it was going to house HF ATU
=A0
=A0
2010/9/19 Stefan Sch=E4fer &l= t;scha= efer@iup.uni-heidelberg.de>
Andy,

QRO can be an exci= ting adventure! :-)

73, GL,

Stefan



Am 19.09.2= 010 12:54, schrieb Andy Talbot:=20
Well, it was nice while it lasted.=A0 Went downstairs and smelt smoke= .=A0=A0 Heard a crackling noise coming from the plastic "shed"= housing the ATU .=A0=A0 Opened the door, saw flames and melted plastic.
=A0
Two buckets of water before they were extinguished - plastic B+Q shed= s burn very well
=A0
Goodbye antenna tuning cabin :-(
=A0
The loading coil and antenna survived.=A0=A0 My credibiilty didn'= t=A0 :-(
=A0
Pictures will follow
On 19 September 2010 11:44, Andy Talbot <andy.g4jnt@googlemail.com> wrote:
Sinece theere were no reports of my QRP WSPR beacon last night two co= nclusions can be drawn :
=A0
a)=A0=A0 No One was listening
b)=A0=A0 Its too weak.
=A0
To resolve=A0=A0 a) ...... ??=A0 Not a lot I can do apart from post= this message :-(
=A0
But to resolve b), I've now fired up the big switchmode PA=A0=A0= http://www.g= 4jnt.com/137tx.pdf=A0=A0=A0=A0=A0=A0
Generating about=A0600 Watts this will increase ERP into the region= of=A0 17dBm
(The WSPR message says 13dBm, but its lying.=A0I've already run= up and downstairs with the PIC programmer, and don't want to do it ag= ain)
=A0
=A0





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