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=-2.2 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_50_60,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 t7GJXVgS018626 for ; Sun, 16 Aug 2015 21:33:31 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ZR3e7-0002Zz-Ow for rs_out_1@blacksheep.org; Sun, 16 Aug 2015 20:31:07 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ZR3e6-0002Zg-TF for rsgb_lf_group@blacksheep.org; Sun, 16 Aug 2015 20:31:06 +0100 Received: from smtpout2.wanadoo.co.uk ([80.12.242.42] helo=smtpout.wanadoo.co.uk) by relay1.thorcom.net with esmtp (Exim 4.86) (envelope-from ) id 1ZR3d0-0006z7-3B for rsgb_lf_group@blacksheep.org; Sun, 16 Aug 2015 20:31:05 +0100 Received: from AGB ([95.150.81.248]) by mwinf5d30 with ME id 5XVi1r0065MTV1K03XViet; Sun, 16 Aug 2015 21:29:42 +0200 X-ME-Helo: AGB X-ME-Date: Sun, 16 Aug 2015 21:29:42 +0200 X-ME-IP: 95.150.81.248 Message-ID: <0BE5E6C9B3A340C09567CEE7317CBADA@AGB> From: "Graham" To: References: <69624027609740299A8700F6BD23175F@AGB><55CF747D.6040909@posteo.de><55CFA62B.5010301@posteo.de><524DB27F17C843798472D2E9E7BA820B@AGB><55D0D89A.3080400@posteo.de><08B4603A596D4233A7376DF32DF26E65@AGB> In-Reply-To: Date: Sun, 16 Aug 2015 20:29:42 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 X-Scan-Signature: 84ab60ecdd4473835b39687102047368 Subject: Re: LF: Some LF again Content-Type: multipart/alternative; boundary="----=_NextPart_000_0061_01D0D862.4805F910" 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: 3902 This is a multi-part message in MIME format. ------=_NextPart_000_0061_01D0D862.4805F910 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable voltage=20 From: Andy Talbot=20 Sent: Sunday, August 16, 2015 8:26 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: Some LF again 6dB per bit=20 '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 =3D 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 ------=_NextPart_000_0061_01D0D862.4805F910 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
voltage

Sent: Sunday, August 16, 2015 8:26 PM
Subject: Re: LF: Some LF again

6dB per bit=20

'jnt


On 16 August 2015 at 20:19, Graham <g8fzk@g8fzk.fsnet.co.uk> wrote:
That's one  of those urban things  = :)

Sure=20 the  abs range  is  3 dB per  bit + 3

But = the=20 reference  point is  floating ,  or  else how to = measure=20 uV  changes , that's under the  control  of the =20  software , which puts the  devices  on the  = 'that's handy=20 list' , there  is a  myth that  dB are directly linked = to=20 $$

Some  conditioning ,  B/W and  gain , may = be  10=20 dB  should  render the device  quite  usable = , =20 noting  you  loose  one mixer and  oscillator , in = the  process : ) what's  the  gain  = compression  in=20 the  mixer ? all  my Hf Rx have  high wattage  = drive =20 to the  first mixer , switching  fet ring , something =20 like   5<>7 watts , with  100  + = range

If=20 it  works , then something  more  exotic  could = be =20 connected  to the out put of the  conditioning  amp, = the =20 air-spy   group  have  'hinted that direct =20 access  to the  a/d  is  provided ,  = while  at=20 the  same  time marketing  a  up convertor = ...  at=20 least there  being  honest .. but that is   24 bit = , =20 72 + 3 =3D 75 dB , still  30 dB  well  short of = the =20  racal mixer , dating  from  1972 , but  with = the =20 right software , will   do  much=20 = better

73-G,



--------------------------------------= ------------
From:=20 "DK7FC" <selberdenken@posteo.de>
Sent: Sunday, August = 16, 2015=20 7:38 PM
To: <rsgb_lf_group@blacksheep.org>
Subject: Re: = LF: Some LF=20 again

Hello G,

As far as i know, the dynamic = range of=20 these dongles is not suitable. 60 dB may be nice for playing arround = but if=20 you want to have a real RX for weak signal detection, something = serious=20 which is running 24/7, like Gary's grabber, you better spend the = time and a=20 bit of money and build something with 100 dB dynamic range. Or, if = you don't=20 like building your own stuff, buy some ready to use equipment, which = is=20 however just half of the hobby, in my opinion ;-)
But designs = covering a=20 whole band (VLF/LF/MF) are up to date i find. Not the SSB and dial=20 stuff.

73, Stefan

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

Gary  sent a = copy =20 of his   cct ,   Im wondering  what  = one  of the  usb dongles  would  make of it = , =20 pre-amp  and  band pass filters =20 = ...

73-G,

-------------------------------------------------= -
From:=20 "DK7FC" <selberdenken@posteo.de>
Sent: Saturday, = August 15,=20 2015 9:50 PM
To: <rsgb_lf_group@blacksheep.org>
Subject: = Re: LF:=20 Some LF again

Hi G,

No, i've made to many = modifications from=20 time to time. There is no up to date schematic.
But, it is a = typical=20 design. A suitable band pass filter, impedance converter = matching to a=20 SBL-3 mixer. The LO is 125 kHz, down-divided by a CMOS 4060 and = a 4 MHz=20 xtal. Then an IF-LPF. That's all. You may need an additional amp = stage,=20 depending on the incoming signal level...

73, = Stefan

Am=20 15.08.2015 21:16, schrieb Graham:
Hi Stefan
Do you  have  a  = link  to  the  CCT  for  the =20 soundcard  Rx ?

Tnx-G

http://myweb.tiscali.co.uk/wgtaylor/136SCRX.jpg
--------------------------------------------------
From:=20 "DK7FC" <selberdenken@posteo.de>
Sent: = Saturday, August=20 15, 2015 6:18 PM
To: <rsgb_lf_group@blacksheep.org>
Subject: LF:=20 Some LF again

Hi LF,

I'm back there is WSPR-15 = for some=20 time. The power is reduced by 4 dB, = unfortunately.

Maybe=20 someone can catch a trace anyway :-)

73,=20 = Stefan/DK7FC







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