Return-Path: Received: from rly-mf07.mx.aol.com (rly-mf07.mail.aol.com [172.20.29.177]) by air-mf03.mail.aol.com (v125.7) with ESMTP id MAILINMF031-96e4b03c1af3a5; Wed, 18 Nov 2009 04:43:22 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-mf07.mx.aol.com (v125.7) with ESMTP id MAILRELAYINMF074-96e4b03c1af3a5; Wed, 18 Nov 2009 04:43:12 -0500 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NAh3S-0000zm-AG for rs_out_1@blacksheep.org; Wed, 18 Nov 2009 09:42:26 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NAh3R-0000zU-4U for rsgb_lf_group@blacksheep.org; Wed, 18 Nov 2009 09:42:25 +0000 Received: from web28104.mail.ukl.yahoo.com ([217.146.182.124]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1NAh3R-00069N-0X for rsgb_lf_group@blacksheep.org; Wed, 18 Nov 2009 09:42:25 +0000 Received: (qmail 46664 invoked by uid 60001); 18 Nov 2009 09:42:19 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.co.uk; s=s1024; t=1258537339; bh=deC8kPsA8Ck/ApTe2iCrMj3g+5XgxhkGj4/mh+VuKWI=; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=iDCkkNXC5JpCpjRSaCdEV0mYsxrX+XVyNAHDrZqcO5YqK5iV4ogx6rarsMkOBHeqjYqBJy/kKs2f1AC1gscZBtKX0qcxd94Kmtm2NvD2FYxHjPRTMtCqwzwz6DY9O2yG39B4nVQNbMuYTeS8PdfjyWKUor+1FYn13/AkLPhUKgA= DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.co.uk; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=xouF5+VioMl3EL0e74TMRqwJBkttZ0IydJjzuHQRJM+Yrw7djni08Y8ijEXO8SOnGbOfMANP1U2jNKWyCB3wJruKLLdvrjAC1idaYvLBd6239oE4/s8iNrWF+H/6TRpIkuAZ9jQ2p+H2WjZoa9R3AdVt4JUodMnlBMw9mAfPEcI=; Message-ID: <477782.43526.qm@web28104.mail.ukl.yahoo.com> X-YMail-OSG: K68l9dcVM1ni97ZVZA_oi0eduBaxQqFTNPOouu9Mu_9Pt6MMJ2CQyAqtIl4NDA6QEAKf_oqYRhHjSWQhiUF3na9wKqbYDIB0qIUog0jeAK4NpYUS.JBmXAbTgqbUpwHq6YxCi8sQb05vmYpM3LexpxEHoHpGAqpNrQt0ZXdlEenaNfX58vfeBEpfErQEZ21qtioSRyYfEvcrOe0c4hiuBzuE5tGtY7C_r4bCjwmJmNfh0btK8TvvCmo9_VKvCkAp5lUwPwmU6mXi7F5hr54RqEP_tITA1Ui6_Ma7fPppnTWKb.Nvi71OeuSjpqGYllI2SlRwuhuwk4oE9w-- Received: from [86.140.72.194] by web28104.mail.ukl.yahoo.com via HTTP; Wed, 18 Nov 2009 01:42:19 PST X-Mailer: YahooMailClassic/8.1.6 YahooMailWebService/0.7.361.4 Date: Wed, 18 Nov 2009 01:42:19 -0800 (PST) From: M0FMT To: rsgb_lf_group@blacksheep.org In-Reply-To: <20091118085815.7282031E703@smtps01.kuleuven.be> MIME-Version: 1.0 X-Karma: unknown: DomainKey-Status: good (testing) Subject: Re: LF: Re: G7NKS sidebands Content-Type: multipart/alternative; boundary="0-1037354559-1258537339=:43526" 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=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-IP: 193.82.116.20 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d226.1 ; domain : yahoo.co.uk DKIM : pass --0-1037354559-1258537339=:43526 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Hi Rik and LF =A0 In Jim's case he has two sidebands indicative of AM modulation and you are= right they are about 30 odd dBs down on the carrier. Not too bad suppress= ion by 1950's standards.... hee hee. Where only one side band is reported= on the data base is probably becuase the reporting station is having the= =A0 (say) lower side band clipped by having a slightly high dial frequency= offset. =A0 I have some JPEG files for the test we did yesterday if you would like to= see them I will send off reflector. You may see something that could help= Jim solve this issue. =A0 73 petefmt --- On Wed, 18/11/09, Rik Strobbe wrote: From: Rik Strobbe Subject: Re: LF: Re: G7NKS sidebands To: "rsgb_lf_group@blacksheep.org" Date: Wednesday, 18 November, 2009, 8:58 Hello Jim, LF group, I have noticed "double receptions" of my WSPR signal from a number of=20 stations. When it occurred the ghost signal was always 100Hz higher=20 and was 33-36dB weaker. As the frequency shift and signal strength difference was the same at=20 the different RX stations I conclude that the cause was with me. I think that it is just some AM modulation in the PA caused by the=20 100Hz ripple of the PSU. 73, Rik=A0 ON7YD - OR7T At 02:13 18/11/2009, you wrote: >Dear Jim LF Group, > >Looking at the sidebands on the G7NKS WSPR signals, mains hum or other no= ise >by itself is not a sufficient explanation of what is seen. Simply adding >50Hz, 150Hz, etc. noise into the PC audio channel, then feeding the resul= t >into an SSB TX would give unwanted CW at frequencies offset from the SSB >carrier frequency by +/-50Hz, 150Hz and so on, i.e. with the carrier "dia= l >frequency" at 502.4kHz, unmodulated carriers would appear at 502.45kHz, >502.55kHz and so on, in addition to the WSPR signal at around 503.9kHz. >However, these would probably largely be removed by the SSB filter in the >rig. Instead, we see unwanted sidebands offset from the wanted WSPR signa= l >frequency by +/- 50Hz, 150Hz, with identical modulation to the wanted >signal. This requires some sort of non-linear process to cause the >intermodulation between the presumed mains noise and the WSPR signal >somewhere in the TX chain. > >One possibility is that intermodulation occurs in the PA. Jim's descripti= on >suggests that he is persuading the HF PA in the IC735 to produce output= at >500k. At this frequency, the PA linearity may well be poor due to the >impedance matching, coupling, decoupling and feedback components in the= PA >being wrong for the frequency, and high flux densities occuring in ferrit= e >components due to the low operating frequency. But this wouldn't explain= why >Jim also gets multiple received signals from a strong station with a clea= n >signal, which implies some identical noise source and distortion in the >receive path. It would also mean the mains noise getting through the >filtering in the rig somehow. > >A possibility that would explain the unwanted sidebands appearing on both= TX >and RX signals is if one of the oscillators in the system has mains noise >sidebands. The sound card clock seems unlikely, since this is just a simp= le >crystal oscillator. I see the IC735 has some sort of multi-loop PLL >synthesiser, which would certainly be prone to this type of spurious sign= al, >since any kind of mains noise getting in would modulate the VCO frequenci= es, >and would probably be the same on transmit and receive. This could be >checked by receiving a clean carrier somewhere around 500kHz, and examini= ng >the audio output using Spec Lab or Argo or similar to see if 50Hz and 150= Hz >sidebands are present on the received audio tone. > >Cheers, Jim Moritz >73 de M0BMU > > >----- Original Message ----- >From: "James Cowburn" >To: >Sent: Monday, November 16, 2009 8:26 PM >Subject: LF: rule #2 - assumption is the brother of all foul ups > > > > LF > > > > > > > > Sidebands are back!=A0 I think its caused by my TX getting hot and bot= hered > > by > > struggling at 500.=A0 From cold it txs 50 watts but this soon drops ba= ck to > > around 35, and the sidebands appear.=A0 My sigs are better so having= the > > txfr > > outside the shack and at the antenna is a vast improvement, but I now= need > > to work on the cooling. =20 --0-1037354559-1258537339=:43526 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Hi Rik and LF
 
In Jim's case he has two sidebands indicative of AM modulation and yo= u are right they are about 30 odd dBs down on the carrier. Not too bad sup= pression by 1950's standards.... hee hee. Where only one side band is repo= rted on the data base is probably becuase the reporting station is having= the  (say) lower side band clipped by having a slightly high dial fr= equency offset.
 
I have some JPEG files for the test we did yesterday if you would lik= e to see them I will send off reflector. You may see something that could= help Jim solve this issue.
 
73 petefmt

--- On Wed, 18/11/09, Rik Strobbe <rik.str= obbe@fys.kuleuven.be> wrote:

From: Rik Strobbe <rik.strobbe@fys.kuleuven= .be>
Subject: Re: LF: Re: G7NKS sidebands
To: "rsgb_lf_group@blac= ksheep.org" <rsgb_lf_group@blacksheep.org>
Date: Wednesday, 18 No= vember, 2009, 8:58

Hello Jim, LF group,

I have noticed "double= receptions" of my WSPR signal from a number of
stations. When it occu= rred the ghost signal was always 100Hz higher
and was 33-36dB weaker.<= BR>As the frequency shift and signal strength difference was the same at=
the different RX stations I conclude that the cause was with me.
I= think that it is just some AM modulation in the PA caused by the
100H= z ripple of the PSU.

73, Rik  ON7YD - OR7T


At 02:13= 18/11/2009, you wrote:
>Dear Jim LF Group,
>
>Looking= at the sidebands on the G7NKS WSPR signals, mains hum or other noise
&= gt;by itself is not a sufficient explanation of what is seen. Simply addin= g
>50Hz, 150Hz, etc. noise into the PC audio channel, then feeding= the result
>into an SSB TX would give unwanted CW at frequencies of= fset from the SSB
>carrier frequency by +/-50Hz, 150Hz and so on, i.= e. with the carrier "dial
>frequency" at 502.4kHz, unmodulated carriers would= appear at 502.45kHz,
>502.55kHz and so on, in addition to the WSPR= signal at around 503.9kHz.
>However, these would probably largely= be removed by the SSB filter in the
>rig. Instead, we see unwanted= sidebands offset from the wanted WSPR signal
>frequency by +/- 50Hz= , 150Hz, with identical modulation to the wanted
>signal. This requi= res some sort of non-linear process to cause the
>intermodulation be= tween the presumed mains noise and the WSPR signal
>somewhere in the= TX chain.
>
>One possibility is that intermodulation occurs= in the PA. Jim's description
>suggests that he is persuading the HF= PA in the IC735 to produce output at
>500k. At this frequency, the= PA linearity may well be poor due to the
>impedance matching, coupl= ing, decoupling and feedback components in the PA
>being wrong for= the frequency, and high flux densities occuring in ferrite
>components due to the= low operating frequency. But this wouldn't explain why
>Jim also ge= ts multiple received signals from a strong station with a clean
>sig= nal, which implies some identical noise source and distortion in the
&g= t;receive path. It would also mean the mains noise getting through the
= >filtering in the rig somehow.
>
>A possibility that would= explain the unwanted sidebands appearing on both TX
>and RX signals= is if one of the oscillators in the system has mains noise
>sideban= ds. The sound card clock seems unlikely, since this is just a simple
&g= t;crystal oscillator. I see the IC735 has some sort of multi-loop PLL
&= gt;synthesiser, which would certainly be prone to this type of spurious si= gnal,
>since any kind of mains noise getting in would modulate the= VCO frequencies,
>and would probably be the same on transmit and re= ceive. This could be
>checked by receiving a clean carrier somewhere aroun= d 500kHz, and examining
>the audio output using Spec Lab or Argo or= similar to see if 50Hz and 150Hz
>sidebands are present on the rece= ived audio tone.
>
>Cheers, Jim Moritz
>73 de M0BMU
&= gt;
>
>----- Original Message -----
>From: "James Cowbur= n" <james.cowburn= @virgin.net>
>To: <rsgb_lf_group@blacksheep.org>
>Sent:= Monday, November 16, 2009 8:26 PM
>Subject: LF: rule #2 - assumptio= n is the brother of all foul ups
>
>
> > LF
>= >
> >
> >
> > Sidebands are back!  I= think its caused by my TX getting hot and bothered
> > by
> > struggling at 50= 0.  From cold it txs 50 watts but this soon drops back to
> >= ; around 35, and the sidebands appear.  My sigs are better so having= the
> > txfr
> > outside the shack and at the antenna= is a vast improvement, but I now need
> > to work on the cooling= .



=20 --0-1037354559-1258537339=:43526--