Return-Path: X-Spam-DCC: paranoid 1233; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.4 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_MESSAGE autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id tBDDAebX016321 for ; Sun, 13 Dec 2015 14:10:40 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1a86N6-0004jF-1i for rs_out_1@blacksheep.org; Sun, 13 Dec 2015 13:07:28 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1a86N5-0004iz-9O for rsgb_lf_group@blacksheep.org; Sun, 13 Dec 2015 13:07:27 +0000 Received: from mail-wm0-f44.google.com ([74.125.82.44]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.86) (envelope-from ) id 1a86MC-0007EQ-37 for rsgb_lf_group@blacksheep.org; Sun, 13 Dec 2015 13:07:26 +0000 Received: by wmpp66 with SMTP id p66so28488228wmp.1 for ; Sun, 13 Dec 2015 05:06:15 -0800 (PST) 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=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=hXbyTKOmjDCcaXCWPGqngxfQVAqYagyjSWCu4GOtdEg=; b=RI1SmtlMSnx2Zy83N6m7QIZMiXJ1QYhaAqH4xwlrtEzOcCSrpTZ9/+rfQR3NdOTL+N ya3R73XSnMOV7Qu5nOhigfRQbpjYw46YPuoJLXWJgMrf+krnlVaNgwiQstO0v47IrNRd /D8cMu7r22dAws+we5iQ85hzSYu0/amCVe8Xe1pzbV+FjQlDnR1moCSBMLhpTzgZkEHJ 9EOfqrzeAHn7oareM3AwX1AexW4BVa73hWOQImZgJTBF+yBJKsv+JpbWW0+QpYlk95/R 52t24yjmcN9jTgaqJ9RggIjQqkRZVHKMP8JHigM9wc4ndtdiP6ZBFnxaVUUIB2oEUi/F pqDg== MIME-Version: 1.0 X-Received: by 10.28.51.135 with SMTP id z129mr18360289wmz.19.1450011975507; Sun, 13 Dec 2015 05:06:15 -0800 (PST) Received: by 10.28.130.139 with HTTP; Sun, 13 Dec 2015 05:06:15 -0800 (PST) In-Reply-To: References: <56686FA0.4050707@gmail.com> <56695B15.6010203@abelian.org> <56696950.1040300@abelian.org> <5669B7CE.1090601@freenet.de> <5669E1E3.6070008@abelian.org> <566D6597.4070901@freenet.de> Date: Sun, 13 Dec 2015 13:06:15 +0000 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org X-Scan-Signature: 4bc3491b614f043141ec87e58a12dcbf Subject: Re: LF: LF EbNaut test from JN80 on 137370 Content-Type: multipart/alternative; boundary=001a1144424eb864b50526c7387e 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 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 5791 --001a1144424eb864b50526c7387e Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable And, once again I managed to find a keyboard shortcut by mistake that sent the message too soon............ I always think only in terms of sin and cos. Real =3D =3D Inphase =3D COS Imag =3D Quadrature =3D SIN So , to shift up in frequency, Fout =3D A + B >From basic trig identities: I term =3D COS(A+B) =3D COS(A).COS(B) - SIN(A).SIN(B) Q term =3D SIN(A+B) =3D SIN(A).COS(B) + COS(A).SIN(B) with A or B replaced by the input samples Andy G4JNT On 13 December 2015 at 12:59, Andy Talbot wrote: > The terms "leading" and "lagging" are the most confusing terms I've ever > come across in AC. A waveform on a scope, to the right of another one > looks as if its leading it. But it is later in time - so its lagging. > > See my point ? > > > > On 13 December 2015 at 12:33, Wolfgang B=C3=BCscher w= rote: > >> Just to confirm (answer a bit late).. >> >> In a file recorded by SpectraVue (the software which came along with the >> SDR-IQ), with the VFO tuned to 77490 Hz, recodring DCF77 on 77500 Hz, >> produces a 'positive' 10 Hz baseband frequency in the I+Q wave file >> recorded by that software. >> And, as expectable for "I" ~ cos(omega*t) and "Q" ~ sin(omega*t), the >> phase of the signal's "I" component *leads* the "Q" component by 90 >> degrees. So, "all ok" with the files recorded by whatever software. >> >> Besides that, it's advisable *not* to tune the SDR exactly to the >> frequency of the EbNaut signal. Detune by a few Hz to avoid having the "= 0 >> Hz" component (after the downconversion, either digital or analog) insid= e >> the decoder's passband. >> >> Now back to local EbNaut testing... >> >> Have a nice sunday an a merry xmas season everyone, >> Wolf . >> >> >> Am 12.12.2015 um 13:12 schrieb Andy Talbot: >> >> Hit send too soon on the last one >> >> On 12 December 2015 at 12:06, Andy Talbot wrote: >> >>> I've just added a fine tune to the PC prog to shift teh input frequeny >>> by any amount specified in a text box >>> >>> >> >> >>> { ipI& and ipQ& are the input samples from the receiver } >>> >> >> >>> LOtheta =3D Val(Tuning.Text) / Fsample >>> LocalOsc =3D LocalOsc + LOtheta 'Both are >>> normalised frequencies (Fsample =3D 1) >>> LocalOsc =3D LocalOsc - Int(LocalOsc) 'Fractional part >>> only >>> theta =3D 2 * pi * LocalOsc >>> >>> IPData(DataPointer&, 0) =3D ipI& * Cos(theta) - ipQ& * >>> Sin(theta) ' I >>> IPData(DataPointer&, 1) =3D ipQ& * Cos(theta) + ipI& * >>> Sin(theta) ' Q >>> >>> The effect of that is for any positive freqeuncy in Hz intereed into >> Tuning.text , the spectrum plot shift positive, and conversely the displ= ay >> shifts wown for any -ve value entered >> >> Andy G4JNT >> >>> >>> >>>> >>>> On 10 December 2015 at 20:34, Paul Nicholson >>>> wrote: >>>> >>>>> >>>>> In vlfrx-tools I use >>>>> >>>>> I =3D s(t) * cos( 2pi * Fo * t); >>>>> >>>>> Q =3D s(t) * sin( 2pi * Fo * t); >>>>> >>>>> where s(t) is the incoming signal and Fo is the >>>>> local oscillator frequency. Is that right, or >>>>> should there be a minus sign in there somewhere? >>>>> >>>>> If s(t) is VO1NA at 137370.00000 and I set Fo to >>>>> 137369.9, then when I put I and Q into EbNaut, it >>>>> needs an offset of +0.1 Hz to decode as you would >>>>> expect with the LO being 0.1Hz on the low side. >>>>> >>>>> For more general mixing and frequency shift, >>>>> to select the upper sideband of the mixer output >>>>> I use >>>>> >>>>> I - j * Q >>>>> >>>>> is that the right way round? When I take I/Q data >>>>> from an RTL2832 I find I have to invert Q to get the >>>>> correct sideband, ie I + j * Q. That's the only >>>>> independent source of I/Q signal that I have available >>>>> to try. >>>>> >>>>> -- >>>>> Paul Nicholson >>>>> -- >>>>> >>>>> >>>> >>> >> >> > --001a1144424eb864b50526c7387e Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
And, once again I managed to find a keyboard shortcut= by mistake that sent the message too soon............

=
I always think only in terms of=C2=A0sin and cos.

=
Real =3D =3D Inphase =3D COS
Imag =3D=C2=A0 Quadrature =3D S= IN

So , to shift up in frequency, Fout =3D A + B

From basic trig identities:
I term=C2=A0= =C2=A0 =3D =C2=A0 COS(A+B) =3D COS(A).COS(B) - SIN(A).SIN(B)
Q te= rm=C2=A0=C2=A0=3D=C2=A0=C2=A0 SIN(A+B) =3D SIN(A).COS(B) + COS(A).SIN(B)

with=C2=A0 A or B replaced by the input samples


Andy=C2=A0 G4JNT


On 13 December 2015= at 12:59, Andy Talbot <andy.g4jnt@gmail.com> wrote:
<= blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;padding-= left:1ex;border-left-color:rgb(204,204,204);border-left-width:1px;border-le= ft-style:solid">
The terms "leading" and &qu= ot;lagging" are the most confusing terms I've ever come across in = AC.=C2=A0 A waveform on a scope, to the right of another one looks as if it= s leading it.=C2=A0=C2=A0 But it is later in time - so its lagging.

See my point ?


<= div class=3D"gmail_extra">
On 13 December 201= 5 at 12:33, Wolfgang B=C3=BCscher <dl4yhf@freenet.de> wrote:=
=20 =20 =20
Just to confirm (answer a bit late)..

In a file recorded by SpectraVue (the software which came along with the SDR-IQ),=C2=A0 with the VFO tuned to 77490 Hz, recodring DCF77 on 77500 Hz, produces a 'positive' 10 Hz baseband frequency in the= I+Q wave file recorded by that software.
And, as expectable for "I" ~ cos(omega*t) and "Q" ~= sin(omega*t), the phase of the signal's "I" component *leads* the "= ;Q" component by 90 degrees. So, "all ok" with the files recorded by whatever software.

Besides that, it's advisable *not* to tune the SDR exactly to the frequency of the EbNaut signal. Detune by a few Hz to avoid having the "0 Hz" component (after the downconversion, either digita= l or analog) inside the decoder's passband.

Now back to local EbNaut testing...

Have a nice sunday an a merry xmas season everyone,
=C2=A0=C2=A0 Wolf .


Am 12.12.2015 um 13:12 schrieb Andy Talbot:
Hit send too soon on the last one

On 12 December 2015 at 12:06, Andy Talbot <andy.g4jnt@gmail.com> wrote:
I've just added a fine tune to the PC pr= og to shift teh input frequeny by any amount specified in a text box
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0
=C2=A0
=C2=A0 { =C2=A0ipI& and ipQ& are the input sam= ples from the receiver =C2=A0}
=C2=A0
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 LOtheta =3D = Val(Tuning.Text) / Fsample =C2=A0
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 LocalOsc = =3D LocalOsc + LOtheta =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 'Both are normalised frequencies (Fsa= mple =3D 1)
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 LocalOsc = =3D LocalOsc - Int(LocalOsc) =C2=A0 =C2=A0 =C2=A0'Fractional part only
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 theta =3D = 2 * pi * LocalOsc
=C2=A0=C2=A0
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 IPData(Dat= aPointer&, 0) =3D ipI& *=C2=A0Cos(theta)=C2=A0- ipQ& * Sin(theta)= =C2=A0 =C2=A0 =C2=A0 ' =C2=A0 =C2=A0I
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 IPData(Dat= aPointer&, 1) =3D ipQ& *=C2=A0Cos(theta)=C2=A0+ ipI& * Sin(theta)= =C2=A0 =C2=A0 =C2=A0' =C2=A0 Q

The effect of that is for any positive freqeuncy in Hz intereed into Tuning.text , the spectrum plot shift positive, and conversely the display shifts wown for any -ve value entered

Andy =C2=A0G4JNT



On 10 December 2015 at 20:34, Paul Nicholson <= vlf0403@abelian.org> wrote:

In vlfrx-tools I use

=C2=A0I =3D s(t) * cos( 2pi * Fo * t);

=C2=A0Q =3D s(t) * sin( 2pi * Fo * t);

where s(t) is the incoming signal and Fo is the
local oscillator frequency.=C2=A0 =C2=A0Is th= at right, or
should there be a minus sign in there somewhere?

If s(t) is VO1NA at 137370.00000 and I set Fo to
137369.9, then when I put I and Q into EbNaut, it
needs an offset of +0.1 Hz to decode as you would
expect with the LO being 0.1Hz on the low side.

For more general mixing and frequency shift,
to select the upper sideband of the mixer output
I use

=C2=A0 =C2=A0I - j * Q

is that the right way round?=C2=A0 =C2=A0When= I take I/Q data
from an RTL2832 I find I have to invert Q to get the
correct sideband, ie I + j * Q.=C2=A0 =C2=A0T= hat's the only
independent source of I/Q signal that I have available
to try.=

--
Paul Nicholson
--
=




--001a1144424eb864b50526c7387e--