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=-2.0 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_30_40,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 t7GJUUUE018616 for ; Sun, 16 Aug 2015 21:30:30 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ZR3an-0002UM-H1 for rs_out_1@blacksheep.org; Sun, 16 Aug 2015 20:27:41 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ZR3an-0002UD-4R for rsgb_lf_group@blacksheep.org; Sun, 16 Aug 2015 20:27:41 +0100 Received: from mail-wi0-f182.google.com ([209.85.212.182]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.86) (envelope-from ) id 1ZR3Zb-0006wm-Me for rsgb_lf_group@blacksheep.org; Sun, 16 Aug 2015 20:27:39 +0100 Received: by wicja10 with SMTP id ja10so63932973wic.1 for ; Sun, 16 Aug 2015 12:26:06 -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=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=DAICUwOU4t3B4btANt5R4th5FrhiaB6nmEEg8pNA5M4=; b=Kuxj93Uho6g7TDtT5aTsmckzHai0MQQK1ixHa+o0nb7fGHbtgq3p+Jtf3QqbMZaEcG 42Exn3wENDy+GFDBGn+GLAYIydIcPraalMIAXjyeiOKANXaXTtBtRtDY7uljI+DBY9hm Cy3vlkDAqj92p2/ugVR5Jef/TP6TCRK72lUZeH9T4oC4D+zpaGbPmV0OvZpuh6wIXF7B A1THFbFnS24MdKiqQjTgUebbBlbkaJ2F/Ks6T8ZserTzhxQ1qv57/d01KncFO7JaDZJz L5S15gfgCccelZbrzStVxYexBjA641Brm/biPLEMlhXvzxacvTqeKiGNGk2KcanvqKjN 2U6g== MIME-Version: 1.0 X-Received: by 10.180.208.81 with SMTP id mc17mr26510735wic.93.1439753166658; Sun, 16 Aug 2015 12:26:06 -0700 (PDT) Received: by 10.28.98.6 with HTTP; Sun, 16 Aug 2015 12:26:06 -0700 (PDT) In-Reply-To: <08B4603A596D4233A7376DF32DF26E65@AGB> References: <69624027609740299A8700F6BD23175F@AGB> <55CF747D.6040909@posteo.de> <55CFA62B.5010301@posteo.de> <524DB27F17C843798472D2E9E7BA820B@AGB> <55D0D89A.3080400@posteo.de> <08B4603A596D4233A7376DF32DF26E65@AGB> Date: Sun, 16 Aug 2015 20:26:06 +0100 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org X-Scan-Signature: ebcef237b0394d499a293e835099e25a Subject: Re: LF: Some LF again Content-Type: multipart/alternative; boundary=001a11c33bb01022f1051d72a8d2 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: 3901 --001a11c33bb01022f1051d72a8d2 Content-Type: text/plain; charset=UTF-8 6dB per bit 'jnt On 16 August 2015 at 20:19, Graham wrote: > That's one of those urban things :) > > Sure the abs range is 3 dB per bit + 3 > > But the reference point is floating , or else how to measure uV > changes , that's under the control of the software , which puts the > devices on the 'that's handy list' , there is a myth that dB are > directly linked to $$ > > Some conditioning , B/W and gain , may be 10 dB should render the > device quite usable , noting you loose one mixer and oscillator , in > the process : ) what's the gain compression in the mixer ? all my Hf > Rx have high wattage drive to the first mixer , switching fet ring , > something like 5<>7 watts , with 100 + range > > If it works , then something more exotic could be connected to the > out put of the conditioning amp, the air-spy group have 'hinted that > direct access to the a/d is provided , while at the same time > marketing a up convertor ... at least there being honest .. but that > is 24 bit , 72 + 3 = 75 dB , still 30 dB well short of the racal > mixer , dating from 1972 , but with the right software , will do > much better > > 73-G, > > > > -------------------------------------------------- > From: "DK7FC" > Sent: Sunday, August 16, 2015 7:38 PM > To: > Subject: Re: LF: Some LF again > > Hello G, >> >> As far as i know, the dynamic range of these dongles is not suitable. 60 >> dB may be nice for playing arround but if you want to have a real RX for >> weak signal detection, something serious which is running 24/7, like Gary's >> grabber, you better spend the time and a bit of money and build something >> with 100 dB dynamic range. Or, if you don't like building your own stuff, >> buy some ready to use equipment, which is however just half of the hobby, >> in my opinion ;-) >> But designs covering a whole band (VLF/LF/MF) are up to date i find. Not >> the SSB and dial stuff. >> >> 73, Stefan >> >> Am 16.08.2015 18:48, schrieb Graham: >> >>> Thanks Stefan, >>> >>> Gary sent a copy of his cct , Im wondering what one of the usb >>> dongles would make of it , pre-amp and band pass filters ... >>> >>> 73-G, >>> >>> -------------------------------------------------- >>> From: "DK7FC" >>> Sent: Saturday, August 15, 2015 9:50 PM >>> To: >>> Subject: Re: LF: Some LF again >>> >>> Hi G, >>>> >>>> No, i've made to many modifications from time to time. There is no up >>>> to date schematic. >>>> But, it is a typical design. A suitable band pass filter, impedance >>>> converter matching to a SBL-3 mixer. The LO is 125 kHz, down-divided by a >>>> CMOS 4060 and a 4 MHz xtal. Then an IF-LPF. That's all. You may need an >>>> additional amp stage, depending on the incoming signal level... >>>> >>>> 73, Stefan >>>> >>>> Am 15.08.2015 21:16, schrieb Graham: >>>> >>>>> Hi Stefan >>>>> Do you have a link to the CCT for the soundcard Rx ? >>>>> >>>>> Tnx-G >>>>> >>>>> http://myweb.tiscali.co.uk/wgtaylor/136SCRX.jpg >>>>> >>>>> -------------------------------------------------- >>>>> From: "DK7FC" >>>>> Sent: Saturday, August 15, 2015 6:18 PM >>>>> To: >>>>> Subject: LF: Some LF again >>>>> >>>>> Hi LF, >>>>>> >>>>>> I'm back there is WSPR-15 for some time. The power is reduced by 4 >>>>>> dB, unfortunately. >>>>>> >>>>>> Maybe someone can catch a trace anyway :-) >>>>>> >>>>>> 73, Stefan/DK7FC >>>>>> >>>>>> >>>>> >>>> >>> >> > --001a11c33bb01022f1051d72a8d2 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
6dB per bit

'jnt


On 16 August 20= 15 at 20:19, Graham <g8fzk@g8fzk.fsnet.co.uk> wrote:
That's one=C2=A0 of those urban things= =C2=A0 :)

Sure the=C2=A0 abs range=C2=A0 is=C2=A0 3 dB per=C2=A0 bit + 3

But the reference=C2=A0 point is=C2=A0 floating ,=C2=A0 or=C2=A0 else how t= o measure uV=C2=A0 changes , that's under the=C2=A0 control=C2=A0 of th= e=C2=A0 =C2=A0software , which puts the=C2=A0 devices=C2=A0 on the=C2=A0 &#= 39;that's handy list' , there=C2=A0 is a=C2=A0 myth that=C2=A0 dB a= re directly linked to $$

Some=C2=A0 conditioning ,=C2=A0 B/W and=C2=A0 gain , may be=C2=A0 10 dB=C2= =A0 should=C2=A0 render the device=C2=A0 quite=C2=A0 usable ,=C2=A0 noting= =C2=A0 you=C2=A0 loose=C2=A0 one mixer and=C2=A0 oscillator , in the=C2=A0 = process : ) what's=C2=A0 the=C2=A0 gain=C2=A0 compression=C2=A0 in the= =C2=A0 mixer ? all=C2=A0 my Hf Rx have=C2=A0 high wattage=C2=A0 drive=C2=A0= to the=C2=A0 first mixer , switching=C2=A0 fet ring , something=C2=A0 like= =C2=A0 =C2=A05<>7 watts , with=C2=A0 100=C2=A0 + range

If it=C2=A0 works , then something=C2=A0 more=C2=A0 exotic=C2=A0 could be= =C2=A0 connected=C2=A0 to the out put of the=C2=A0 conditioning=C2=A0 amp, = the=C2=A0 air-spy=C2=A0 =C2=A0group=C2=A0 have=C2=A0 'hinted that direc= t=C2=A0 access=C2=A0 to the=C2=A0 a/d=C2=A0 is=C2=A0 provided ,=C2=A0 while= =C2=A0 at the=C2=A0 same=C2=A0 time marketing=C2=A0 a=C2=A0 up convertor ..= .=C2=A0 at least there=C2=A0 being=C2=A0 honest .. but that is=C2=A0 =C2=A0= 24 bit ,=C2=A0 72 + 3 =3D 75 dB , still=C2=A0 30 dB=C2=A0 well=C2=A0 short = of the=C2=A0 =C2=A0racal mixer , dating=C2=A0 from=C2=A0 1972 , but=C2=A0 w= ith the=C2=A0 right software , will=C2=A0 =C2=A0do=C2=A0 much better

73-G,



--------------------------------------------------
From: "DK7FC" <selberdenken@posteo.de>
Sent: Sunday, August 16, 2015 7:38 PM
To: <r= sgb_lf_group@blacksheep.org>
Subject: Re: LF: Some LF again

Hello G,

As far as i know, the dynamic range of these dongles is not suitable. 60 dB= may be nice for playing arround but if you want to have a real RX for weak= signal detection, something serious which is running 24/7, like Gary's= grabber, you better spend the time and a bit of money and build something = with 100 dB dynamic range. Or, if you don't like building your own stuf= f, buy some ready to use equipment, which is however just half of the hobby= , in my opinion ;-)
But designs covering a whole band (VLF/LF/MF) are up to date i find. Not th= e SSB and dial stuff.

73, Stefan

Am 16.08.2015 18:48, schrieb Graham:
Thanks=C2=A0 Stefan,

Gary=C2=A0 sent a copy=C2=A0 of his=C2=A0 =C2=A0cct ,=C2=A0 =C2=A0Im wonder= ing=C2=A0 what=C2=A0 one=C2=A0 of the=C2=A0 usb dongles=C2=A0 would=C2=A0 m= ake of it ,=C2=A0 pre-amp=C2=A0 and=C2=A0 band pass filters=C2=A0 ...

73-G,

--------------------------------------------------
From: "DK7FC" <selberdenken@posteo.de>
Sent: Saturday, August 15, 2015 9:50 PM
To: <r= sgb_lf_group@blacksheep.org>
Subject: Re: LF: Some LF again

Hi G,

No, i've made to many modifications from time to time. There is no up t= o date schematic.
But, it is a typical design. A suitable band pass filter, impedance convert= er matching to a SBL-3 mixer. The LO is 125 kHz, down-divided by a CMOS 406= 0 and a 4 MHz xtal. Then an IF-LPF. That's all. You may need an additio= nal amp stage, depending on the incoming signal level...

73, Stefan

Am 15.08.2015 21:16, schrieb Graham:
Hi Stefan
Do you=C2=A0 have=C2=A0 a=C2=A0 link=C2=A0 to=C2=A0 the=C2=A0 CCT=C2=A0 for= =C2=A0 the=C2=A0 soundcard=C2=A0 Rx ?

Tnx-G

http://myweb.tiscali.co.uk/wgtaylor/136SCRX.jpg
--------------------------------------------------
From: "DK7FC" <selberdenken@posteo.de>
Sent: Saturday, August 15, 2015 6:18 PM
To: <r= sgb_lf_group@blacksheep.org>
Subject: LF: Some LF again

Hi LF,

I'm back there is WSPR-15 for some time. The power is reduced by 4 dB, = unfortunately.

Maybe someone can catch a trace anyway :-)

73, Stefan/DK7FC







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