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=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,HTML_MESSAGE,RCVD_IN_DNSWL_MED, SPF_PASS,T_DKIM_INVALID autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: EATSERVER: mailn 1166; 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 v5HDIAik027436 for ; Sat, 17 Jun 2017 15:18:11 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1dMDY9-0004H6-H3 for rs_out_1@blacksheep.org; Sat, 17 Jun 2017 14:14:01 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1dMDY9-0004Gx-4P for rsgb_lf_group@blacksheep.org; Sat, 17 Jun 2017 14:14:01 +0100 Received: from mail-qt0-x22d.google.com ([2607:f8b0:400d:c0d::22d]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1dMDXr-0000tW-9C for rsgb_lf_group@blacksheep.org; Sat, 17 Jun 2017 14:13:59 +0100 Received: by mail-qt0-x22d.google.com with SMTP id c10so86655388qtd.1 for ; Sat, 17 Jun 2017 06:13:42 -0700 (PDT) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=ICVVZndPZlWjbl9sNPpABdab6aS/ePz+muE4X4y7Qac=; b=bOBfZVBMaWxZyXkBqVFRstiatBZkonGDW1G41bT/OmUNteoF+rfTg/kyqnvBf8Qj28 IONW+Yu76WGvo4RatMXx02aKS3pbxOGzoV+flcg6XxG5VOsYvY9ilOez1PUpXeUb9KaK UNwAzM0GdTVBA5Oku5cIjD3jkLYHwG/scBY6ieePAV0TAXTadS2el6315NA3/M26SwVX TUq4iyCxh++QmdUs1qysFW+OQU2d/AwQiLi4JqZy0Yv73150ZDv/TKB2wIohBkEpqxtk Cnt6nKgdL31efd9B4Zu/2KwRA/jETUwS3IHrLodobgspV1tGc+/jFEuP4/IHKelrclWH HZvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=ICVVZndPZlWjbl9sNPpABdab6aS/ePz+muE4X4y7Qac=; b=hulhEhTdD6vm0h4Qx+kQ0dJcatBpHch28nLg4KFPK/kuDW9OpNsyGjO0VmshyVpMP0 LtO/t615kpq6x47OsSflnyegl+XRQ4a55PAX7+Xv3v7Su0DvWO6zdUP28K0RVjkk0tRo tJBbiQ7U5lFJd/AZ6Lvmcge8UDdlbYAlVXT38tMxD6kZUvJkEbhKlJ9485+ZKnPWFYIT +wMPJCJM9lXpSZVpX/USClcM7Po85B6R2H5sWXML9CIEA0udb8rveGS1ZEvvK7UViEaF KM6e+aKxAtjSPXAPmTybiVzClkd1uUWhXYwmmRETr0bsuE8NflNyLjSFr/xv1lkeVlDy IsCQ== X-Gm-Message-State: AKS2vOyRpZe7Ac78ht4UDXRqs8vdeg2KkZFTtUCBYpJoP6zwdqdZUhvc 4nhaiI2g522J0nID+de4aNwWGDvh9w== X-Received: by 10.237.44.7 with SMTP id f7mr19079843qtd.142.1497705221299; Sat, 17 Jun 2017 06:13:41 -0700 (PDT) MIME-Version: 1.0 Received: by 10.200.45.48 with HTTP; Sat, 17 Jun 2017 06:13:40 -0700 (PDT) In-Reply-To: <1508034468.20170617135238@gmail.com> References: <59451931.7040701@posteo.de> <1508034468.20170617135238@gmail.com> From: Chris Osborn Date: Sat, 17 Jun 2017 14:13:40 +0100 Message-ID: To: LF Group X-Scan-Signature: 4a8faa6952847c1ec651f883b63fc053 Subject: Re: LF: WSPR problems Content-Type: multipart/alternative; boundary="94eb2c05df90b1a294055227ab98" 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: 12003 --94eb2c05df90b1a294055227ab98 Content-Type: text/plain; charset="UTF-8" Thanks for the advice Chris. The RF in the shack is quite strong despite the TX only running 100W I've been fiddling and it looks as if it's an earth loop problem. I'll re-jig the cabling and earthing and hopefully sort it out. Thanks again for the advice chaps. 73 Chris On Sat, Jun 17, 2017 at 1:52 PM, Chris Wilson wrote: > Hello Chris, > > Is anything else picking up RF? I had a sort of similar issue ages ago > whereby using an autotransformer to impedance match to the loading > coil RF seemed to abound everywhere it shouldn't and the workshop > alarm would trigger as well as the house mains panel RCD tripping. > Then it killed the TV aerial distribution amp in the loft... The > computer broadband would go slow or just stop, lots of issues. I cured > all in one fell swoop by changing from an auto transformer impedance > match to a conventional isolation transformer. I still had the odd FET > failure at the end of a WSPR transmission when the gate signal would > go wild, that was fixed by lots of 0.1uF ceramics on the 5 and 12V > rails to any IC's in play, as near the pins as possible. Have you > considered a QRP Labs U3S as the exciter, they seem pretty immune to > anything like you see from the PC sound card if nothing else works. > Good luck! > > Saturday, June 17, 2017, 1:26:21 PM, you wrote: > > > Hi Stefan, > > > Many thanks for the prompt reply. > > I shall do as you suggest and hopefully cure the problem. > > > 73 > > Chris > > > > On Sat, Jun 17, 2017 at 12:57 PM, DK7FC wrote: > > > Hi Chris, > > > > Try a 1:1 RF ferrite decoupling trasformer, right behind the PA. > > Maybe also on the PA input. Try to use a battery for the PA, just > > for one WSPR sequence, to see if that solves the problem. If it > > does, then use common mode chokes in the PA supply cable. Avoid > > ground loops. Use shielded circuits only. > > > > 73, Stefan > > > > > Am 17.06.2017 13:20, schrieb Chris Osborn: > > > > GA LF, > > > > I have a recurring problem with my home made LF WSPR TX :- > > > > As the PC's audio signal shuts down (after the nominal 2 minute > > transmission time) it picks up RF - this is fed back to the TX > > input causing several seconds of instability. > > > > Has anyone else had this trouble and/or knows of a simple solution? > > > > I've tried putting ferrite rings around the PC's input and output > > cables which solved the problem for a while. > > > > In desperation I'm considering adding a monostable to ground the > > TX input for a few seconds after the PC's AF shuts down, but this will > be a last resort. > > > > Any useful advice or comments would be most welcome. > > > > 73 > > Chris (G3XIZ) > > > > > > -- > Best regards, > Chris mailto:dead_fets@gmail.com > > > --94eb2c05df90b1a294055227ab98 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Thanks for the advice Chris.
<= /div>The RF in the shack is quite strong despite the TX only running 100W
I've been fiddling and it looks as if it's an earth loo= p problem.
I'll re-jig the cabling and earthing and hopefully = sort it out.

Thanks again for the advice chaps.

73
<= /div>Chris

On Sat, Jun 17, 2017 at 1:52 PM, Chris Wilson <dead.fets@gmail.com> wrote:
Hello Chris,

Is anything else picking up RF? I had a sort of similar issue ages ago
whereby using an autotransformer to impedance match to the loading
coil RF seemed to abound everywhere it shouldn't and the workshop
alarm would trigger as well as the house mains panel RCD tripping.
Then it killed the TV aerial distribution amp in the loft... The
computer broadband would go slow or just stop, lots of issues. I cured
all in one fell swoop by changing from an auto transformer impedance
match to a conventional isolation transformer. I still had the odd FET
failure at the end of a WSPR transmission when the gate signal would
go wild, that was fixed by lots of 0.1uF ceramics on the 5 and 12V
rails=C2=A0 to=C2=A0 any=C2=A0 IC's=C2=A0 in=C2=A0 play, as near the pi= ns as possible. Have you
considered=C2=A0 a=C2=A0 QRP Labs U3S as the exciter, they seem pretty immu= ne to
anything=C2=A0 like=C2=A0 you=C2=A0 see from the PC sound card if nothing e= lse works.
Good luck!

Saturday, June 17, 2017, 1:2= 6:21 PM, you wrote:

> Hi Stefan,

> Many thanks for the prompt reply.
> I shall do as you suggest and hopefully cure the problem.

> 73
> Chris


> On Sat, Jun 17, 2017 at 12:57 PM, DK7FC <selberdenken@posteo.de> wrote:

> Hi Chris,
>
>=C2=A0 Try a 1:1 RF ferrite decoupling trasformer, right behind the PA.=
> Maybe also on the PA input. Try to use a battery for the PA, just
> for one WSPR sequence, to see if that solves the problem. If it
> does, then use common mode chokes in the PA supply cable. Avoid
> ground loops. Use shielded circuits only.
>
>=C2=A0 73, Stefan

>
>=C2=A0 Am 17.06.2017 13:20, schrieb Chris Osborn:
>
>=C2=A0 GA LF,
>
>=C2=A0 I have a recurring problem with my home made LF WSPR TX=C2=A0 :-=
>
>=C2=A0 As the PC's audio signal shuts down (after the nominal 2 min= ute=C2=A0
> transmission time) it picks up RF=C2=A0 -=C2=A0 this is fed back to th= e TX
> input causing several seconds of instability.
>
>=C2=A0 Has anyone else had this trouble and/or knows of a simple soluti= on?
>
>=C2=A0 I've tried putting ferrite rings around the PC's input a= nd output
> cables which solved the problem for a while.
>
>=C2=A0 In desperation I'm considering adding a monostable to ground= the
> TX input for a few seconds after the PC's AF shuts down, but this = will be a last resort.
>
>=C2=A0 Any useful advice or comments would be most welcome.
>
>=C2=A0 73
>=C2=A0 Chris (G3XIZ)





--
Best regards,
=C2=A0Chris=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 mailto:dead_fets@gmail.com



--94eb2c05df90b1a294055227ab98--