Return-Path: Received: from mtain-md03.r1000.mx.aol.com (mtain-md03.r1000.mx.aol.com [172.29.96.87]) by air-mb08.mail.aol.com (v129.10) with ESMTP id MAILINMB081-a7d34db06f1339; Thu, 21 Apr 2011 13:53:23 -0400 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-md03.r1000.mx.aol.com (Internet Inbound) with ESMTP id AB01A380000A2; Thu, 21 Apr 2011 13:53:19 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1QCy2s-0000q1-MG for rs_out_1@blacksheep.org; Thu, 21 Apr 2011 18:52:02 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1QCy2s-0000ps-3M for rsgb_lf_group@blacksheep.org; Thu, 21 Apr 2011 18:52:02 +0100 Received: from mail-iw0-f171.google.com ([209.85.214.171]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1QCy2p-0006RX-Rz for rsgb_lf_group@blacksheep.org; Thu, 21 Apr 2011 18:52:02 +0100 Received: by iwn8 with SMTP id 8so2448992iwn.16 for ; Thu, 21 Apr 2011 10:51:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:date :message-id:subject:from:to:content-type; bh=odYXLip7WrNq/WdoA9sGbcKZGe/PjuCtK+Gy0pev7tw=; b=ANoiuyZsbSuDElCCofzNJgf0V7Wdv/5+CSL87ErZViapuPFF5z5emaBkIud3iUbc+/ D/pCrx24lvD5fzU/viRWNQ7YygaAitrovttDahOtO3HtDGflVEMbpvXblu9LPtSiyKG2 VAKv/vDI9VoeeDru6K1jEuNzTjqxv+7kxdyNM= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=L2HzyomRNKPLXAANQc5KCA0qGllUquqzg1WE/gjXwL4sLnMOyIrCQwzm87flOig3IH vq4nFOnhWb4hnPeruMaOStNPMjeXjUfKKIZMnTBo+R8yB25dPsGftWGWAyBqXz/gLG2G SJQxhLCgX48VoTdkiRaDMelDqEckZdYay32g8= MIME-Version: 1.0 Received: by 10.231.61.18 with SMTP id r18mr190330ibh.71.1303408313139; Thu, 21 Apr 2011 10:51:53 -0700 (PDT) Received: by 10.231.207.75 with HTTP; Thu, 21 Apr 2011 10:51:53 -0700 (PDT) In-Reply-To: References: <4DAF42C1.8010401@telus.net> <4DAF7A16.4040208@telus.net> Date: Thu, 21 Apr 2011 18:51:53 +0100 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org DomainKey-Status: good (testing) X-Spam-Score: 0.3 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,MAILTO_TO_SPAM_ADDR=0.276 Subject: Re: LF: MSK with a Class D transmitter...? Content-Type: multipart/alternative; boundary=0015174929568083f804a17165f9 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.6 required=5.0 tests=HTML_20_30, HTML_FONTCOLOR_UNSAFE,HTML_MESSAGE,MAILTO_TO_SPAM_ADDR 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-global-disposition: G X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d272.1 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d60574db06f0e36ee X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none X-Mailer: Unknown (No Version) --0015174929568083f804a17165f9 Content-Type: text/plain; charset=ISO-8859-1 WSPR isn't MSK.. (Minimum Shift Keying) Its MFSK (Multi Frequency Shift Keying) 'jnt On 21 April 2011 18:46, Rik Strobbe wrote: > Hello Scott, > > > > what kind of MSK do you want to transmit ? > > WSPR by any chance ? > > > > 73, Rik ON7YD - OR7T > > > On 21 April 2011 01:28, Scott Tilley wrote: > >> Hi Andy >> >> Holy mind bogglingness batman... >> >> Here's the parameters to make this real simple: >> - I want to generate a MSK signal out of the transmitter at 8970Hz. >> - I'm using Spectrum Lab, which allows me to create a MSK drive and at a >> baud rate I want at any frequency my sound card can generate. >> - SL allows me to output quadrature outputs. >> >> So, If I understand correctly pump said FET driver with the quadrature >> outputs from the sound card audio (squaring up the sine waves of course) and >> it should work? >> >> Thanks, >> Scott >> >> >> >> >> >> >> On 4/20/2011 2:09 PM, Andy Talbot wrote: >> >> Bin too quick to type.. >> NOt thinking straight... >> >> You need to the upconvert either the resulting doubled audio tone by twice >> the RF carrier, or upconvert first and double the final RF. Same ideas for >> frequency doubling can be used. >> >> See http://www.g4jnt.com/LFUpconv.pdf for a direct from audio >> upconverter. >> >> Must fully check before hitting SEND ! >> >> Andy >> G4JNT >> >> On 20 April 2011 21:50, Andy Talbot wrote: >> >>> I assume you are genrating the MSK from soundcard output, in which case >>> two options come to mind: >>> >>> 1) Double the frequency. Full wave rectify the audio sinusoid, pass the >>> AC part of the result into a comparator and into the divider. >>> Alternatively, as the signal bandwidth is probably quite low, square up the >>> audio to start with, feed into one inpiut of an XOR gate. Delay the >>> waveform by 90 deg and feed this into the othe side of the XOR. Output of >>> XOR to divider as before >>> >>> 2) Remove the divide by two, and replace with an inverter / buffer >>> pair to generate the out of phase drive signals. The input now needs to >>> be close to a 1:1 squarwave at output frequency. Pass the soundcard audio >>> into a comparator and make sure it gives a 50% duty cycles. >>> >>> >>> Andy >>> www.g4jnt.com >>> >>> ps. >>> or 3) Convince the software author the S/W needs modifying to give a >>> 2.F output >>> >>> >>> On 20 April 2011 21:32, Scott Tilley wrote: >>> >>>> Hi All >>>> >>>> I wonder if someone can explain to me how to feed an MSK signal into a >>>> typical Class D transmitter? >>>> >>>> I mean by typical that the TX has a 4013 type /2 system feeding two FET >>>> drivers to drive FETs in a push-pull configuration. >>>> >>>> If I understand correctly due to the fact MSK does not have amplitude >>>> component to its signal that a non-linear transmitter can be used. >>>> >>>> So, how do you do this with a Class-D TX as often used in LF/VLF? >>>> >>>> Thanks, >>>> Scott >>>> VE7TIL >>>> >>>> >>>> >>>> >>> >> >> > --0015174929568083f804a17165f9 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
WSPR isn't MSK..=A0 (Minimum Shift Keying)
Its MFSK=A0=A0 (Multi Frequency Shift Keying)
=A0
'jnt


=A0
On 21 April 2011 18:46, Rik Strobbe <Rik.Strobbe@fy= s.kuleuven.be> wrote:
Hello Scott,

=A0

what kind of MSK do you want to transm= it ?

WSPR by any chance ?

=A0

73, Rik=A0 ON7YD - OR7T


=A0
On 21 April 2011 01:28, Scott Tilley <sthed= 475@telus.net> wrote:
Hi Andy

Holy mind bogglingness batman...
Here's the parameters to make this real simple:
- I want to= generate a MSK signal out of the transmitter at 8970Hz.
- I'm usin= g Spectrum Lab, which allows me to create a MSK drive and at a baud rate= I want at any frequency my sound card can generate.
- SL allows me to output quadrature outputs.

So, If I understand co= rrectly pump said FET driver with the quadrature outputs from the sound ca= rd audio (squaring up the sine waves of course) and it should work?
Thanks,
Scott=20






On 4/20/2011 2:09 PM, Andy Talbot wrote:=20
Bin too quick to type..
NOt thinking straight...
=A0
You need to the upconvert either the resulting doubled audio tone by= twice the RF carrier, or upconvert first and double the final RF.=A0 Same= ideas for frequency doubling can be used.
=A0
See h= ttp://www.g4jnt.com/LFUpconv.pdf=A0 for a direct from audio upconverte= r.
=A0
Must fully check before hitting SEND !
=A0
Andy
G4JNT

On 20 April 2011 21:50, Andy Talbot <and= y.g4jnt@gmail.com> wrote:
I assume you are genrating the MSK=A0from soundcard output, in which= case two options come to mind:
=A0
1)=A0 Double the frequency.=A0 Full wave rectify the audio sinusoid,= pass the AC part of the result into a comparator and into=A0the divider.= =A0 Alternatively,=A0as the signal bandwidth is probably quite low, square= up the audio to start with, feed into one inpiut of an XOR gate.=A0 Delay= the waveform by 90 deg and feed this into the othe side of the XOR.=A0=A0= =A0 Output of XOR to divider as before
=A0
2)=A0=A0 Remove the=A0 divide by two, and replace with an inverter /= buffer pair to generate the out of phase drive signals.=A0=A0 The=A0=A0in= put now needs to be close to a 1:1 squarwave at output frequency.=A0=A0 Pa= ss the soundcard audio into a comparator and make sure it gives a 50% duty= cycles.
=A0
=A0
Andy
=A0
ps.=20
or 3)=A0=A0=A0 Convince the software author the S/W needs modifying= to give a 2.F output
=A0
=A0
On 20 April 2011 21:32, Scott Tilley <sthed= 475@telus.net> wrote:
Hi All

I= wonder if someone can explain to me how to feed an MSK signal into a typi= cal Class D transmitter?

I mean by typical that the TX has a 4013 type /2 system feeding two FE= T drivers to drive FETs in a push-pull configuration.

If I understa= nd correctly due to the fact MSK does not have amplitude component to its= signal that a non-linear transmitter can be used.

So, how do you do this with a Class-D TX as often used in LF/VLF?
<= br>Thanks,
Scott
VE7TIL




=




--0015174929568083f804a17165f9--