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=-1.9 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_40_50,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 tBCCCtr6013945 for ; Sat, 12 Dec 2015 13:12:55 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1a7iyJ-0005ZA-OU for rs_out_1@blacksheep.org; Sat, 12 Dec 2015 12:08:19 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1a7iyJ-0005Z1-EJ for rsgb_lf_group@blacksheep.org; Sat, 12 Dec 2015 12:08:19 +0000 Received: from mail-wm0-f45.google.com ([74.125.82.45]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.86) (envelope-from ) id 1a7ixF-00013C-53 for rsgb_lf_group@blacksheep.org; Sat, 12 Dec 2015 12:08:18 +0000 Received: by mail-wm0-f45.google.com with SMTP id l68so47489795wml.0 for ; Sat, 12 Dec 2015 04:06:54 -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=wW4fH1MZPNW4LjdDKx33mYlo57qxOhzt+vSIfqMiJ3s=; b=qtD+82sS4L10S3WOQ/rpPwUKs6dO37S77aoJ8SxuPlc7N774zMpXFngrxyoIUD6/Q4 2b5XDdATF8rJkGQdg84f28gU85wI2zT5gew3ajPjf1gyUlpzjSsk/mDFpVZtWHC6tcf0 biFpvm6MY490TlEk/a5v8/xDlNHtWpDKE0jUaiPO5O1zjSa7oZrFhqR8XdssnCU6V6m5 SsqEZvcnhuh1BNCxPaI8SflxUlj2MCE0FJ9vtYEyGoLKdLBee3wR3k1OvGv6ZEygfETY mTK8Vc5CGuRItEMtuFqQIzOhEfsruHGXOd8vYwHAtzMtXtk50JihVvvJ2hBIvinmr18p +2JA== MIME-Version: 1.0 X-Received: by 10.28.15.194 with SMTP id 185mr12692801wmp.9.1449922014108; Sat, 12 Dec 2015 04:06:54 -0800 (PST) Received: by 10.28.130.139 with HTTP; Sat, 12 Dec 2015 04:06:54 -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> Date: Sat, 12 Dec 2015 12:06:54 +0000 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org X-Scan-Signature: 622b0ca3461797caf37867321c193763 Subject: Re: LF: LF EbNaut test from JN80 on 137370 Content-Type: multipart/alternative; boundary=001a11469edc9a66700526b2462c 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: 5775 --001a11469edc9a66700526b2462c Content-Type: text/plain; charset=UTF-8 I've just added a fine tune to the PC prog to shift teh input frequeny by any amount specified in a text box LOtheta = Val(Tuning.Text) / Fsample LocalOsc = LocalOsc + LOtheta 'Both are normalised frequencies (Fsample = 1) LocalOsc = LocalOsc - Int(LocalOsc) theta = 2 * pi * LocalOsc IPData(DataPointer&, 0) = ipI& * Cos(theta) - ipQ& * Sin(theta) IPData(DataPointer&, 1) = ipQ& * Cos(theta) + ipI& * Sin(theta) > > On 10 December 2015 at 20:34, Paul Nicholson wrote: > >> >> In vlfrx-tools I use >> >> I = s(t) * cos( 2pi * Fo * t); >> >> Q = 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 >> -- >> >> > --001a11469edc9a66700526b2462c Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
I've just added a fine tune to the PC prog to shift te= h input frequeny by any amount specified in a text box

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 (Fs= ample =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 =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(DataPointer&, 0) =3D ipI&= *=C2=A0Cos(theta)=C2=A0- ipQ& * Sin(theta)
=C2=A0 =C2=A0 =C2= =A0 =C2=A0 =C2=A0 =C2=A0 IPData(DataPointer&, 1) =3D ipQ& *=C2=A0Co= s(theta)=C2=A0+ ipI& * Sin(theta)


=

On 10 D= ecember 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 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

=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=A0That's the only
independent source of I/Q signal that I have available
to try.

--
Paul Nicholson
--



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