Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dl04.r1000.mx.aol.com (Internet Inbound) with ESMTP id 8B3EC380038D5; Wed, 25 Apr 2012 12:06:45 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1SN4iR-0000jb-7B for rs_out_1@blacksheep.org; Wed, 25 Apr 2012 17:05:15 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1SN4iQ-0000jS-8T for rsgb_lf_group@blacksheep.org; Wed, 25 Apr 2012 17:05:14 +0100 Received: from mout0.freenet.de ([195.4.92.90]) by relay1.thorcom.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.77) (envelope-from ) id 1SN4i3-00047a-QO for rsgb_lf_group@blacksheep.org; Wed, 25 Apr 2012 17:05:13 +0100 Received: from [195.4.92.141] (helo=mjail1.freenet.de) by mout0.freenet.de with esmtpa (ID dl4yhf@freenet.de) (port 25) (Exim 4.76 #1) id 1SN4hv-0003Dv-LS for rsgb_lf_group@blacksheep.org; Wed, 25 Apr 2012 18:04:43 +0200 Received: from localhost ([::1]:49932 helo=mjail1.freenet.de) by mjail1.freenet.de with esmtpa (ID dl4yhf@freenet.de) (Exim 4.76 #1) id 1SN4hu-0003WV-E9 for rsgb_lf_group@blacksheep.org; Wed, 25 Apr 2012 18:04:42 +0200 Received: from [195.4.92.10] (port=35932 helo=0.mx.freenet.de) by mjail1.freenet.de with esmtpa (ID dl4yhf@freenet.de) (Exim 4.76 #1) id 1SN4fM-0002SG-No for rsgb_lf_group@blacksheep.org; Wed, 25 Apr 2012 18:02:04 +0200 Received: from blfd-4db035b8.pool.mediaways.net ([77.176.53.184]:1412 helo=[192.168.178.21]) by 0.mx.freenet.de with esmtpsa (ID dl4yhf@freenet.de) (TLSv1:CAMELLIA256-SHA:256) (port 465) (Exim 4.76 #1) id 1SN4fM-0001dO-4q for rsgb_lf_group@blacksheep.org; Wed, 25 Apr 2012 18:02:04 +0200 Message-ID: <4F981FFA.20201@freenet.de> Date: Wed, 25 Apr 2012 18:02:02 +0200 From: wolf_dl4yhf User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:11.0) Gecko/20120327 Thunderbird/11.0.1 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: In-Reply-To: X-Spam-Score: -0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Hi Roger and group, I think Stefan has already answered most of the questions. Indeed you can (should) use the same instance to lock the sampling rate to a reference, and produce a stable output signal. But there's a catch: Even if the input (A/D converter) and output (D/A converter) are in the same device ("soundcard"), their sampe rates may be slightly different even if both are configured for the same nominal SR (like 44100 or -often better- 48000 samples/second). This doesn't seem to be a common problem, but I have experienced it myself in one of my PCs. One would need a control loop (soundcard's output fed back into the input) to correct the output sampling rate, but this would make things overly complicated and thus it isn't implemented in Spectrum Lab (at least not directly). Also, if input and output sampling rate are "slightly different", it becomes a nightmare to manage the audio buffers so there is neither a sporadic input-overflow or output-underflow. Both cases of overflow cause an audible phase glitch in the output. Much easier and more reliable to build a dedicated hardware, clocked by a 10 MHz reference, using a PLL, DDS, or similar. [...] Content analysis details: (-0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [195.4.92.90 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (dl4yhf[at]freenet.de) -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message X-Scan-Signature: f82786fce13a7bdfc3036eb41b44b924 Subject: Re: LF: Generating 8970 Hz carrier with Spectrum Lab ? Content-Type: multipart/alternative; boundary="------------010302090208060405000007" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.6 required=5.0 tests=HTML_20_30, HTML_FONTCOLOR_UNSAFE,HTML_MESSAGE 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-SCORE: 0:2:441418976:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d4ad24f9821144307 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. --------------010302090208060405000007 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Hi Roger and group, I think Stefan has already answered most of the questions. Indeed you can (should) use the same instance to lock the sampling rate to a reference, and produce a stable output signal. But there's a catch: Even if the input (A/D converter) and output (D/A converter) are in the same device ("soundcard"), their sampe rates may be slightly different even if both are configured for the same nominal SR (like 44100 or -often better- 48000 samples/second). This doesn't seem to be a common problem, but I have experienced it myself in one of my PCs. One would need a control loop (soundcard's output fed back into the input) to correct the output sampling rate, but this would make things overly complicated and thus it isn't implemented in Spectrum Lab (at least not directly). Also, if input and output sampling rate are "slightly different", it becomes a nightmare to manage the audio buffers so there is neither a sporadic input-overflow or output-underflow. Both cases of overflow cause an audible phase glitch in the output. Much easier and more reliable to build a dedicated hardware, clocked by a 10 MHz reference, using a PLL, DDS, or similar. All the best, Wolf . Am 25.04.2012 11:38, schrieb Roger Lapthorn: > Peter, > > I hope the experts like Wolf and Stefan can help. > > Another question for Wolf etc: how would one use a single PC with two > instances of SL running to (a) lock the soundcard to an 18-22kHz MSK > signal like GBZ one one instance and then (b) generate a (frequency > stable and locked) output signal for an 8.970kHz TX? > > It is some months since I have used SL and I was never what might be > called an "expert user". > > 73s > Roger G3XBM > > > > > > On 25 April 2012 10:12, PA1SDB, Peter > wrote: > > Hello VLF, > I like to do some local test here with Spectrum lab setings (and > who knows, High ERP transmissions later :-) > I have here a notebook that generates a signal with the Signal > generator in Spectrum Lab at 8970.1 Hz. > It has a Loop connected at the input and thats how it is locked to > a GDO (HWU, FTA, what is available) > I tried several, and that Lock wondow gets green, but output looks > terrible. > To radiate the signal I use a pice of wire at the notebook LS output. > Below two grab's over the same periode of time. > My localy generated signal at 8970.100 Hz and for comparison the > signal of DJ8WX at 8970.022 Hertz. > Both grab's are made with the same Spectrum Lab task. > Why does my signal look like a widband FM transmission ? > Best 73's, Peter - PA1SDB > > > > > -- > http://g3xbm-qrp.blogspot.com/ > http://www.g3xbm.co.uk > https://sites.google.com/site/sub9khz/ > http://qss2.blogspot.com/ > --------------010302090208060405000007 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Hi Roger and group,

I think Stefan has already answered most of the questions.
Indeed you can (should) use the same instance to lock the sampling rate to a reference, and produce a stable output signal.
But there's a catch:
Even if the input (A/D converter) and output (D/A converter) are in the same device ("soundcard"), their sampe rates may be slightly different even if both are configured for the same nominal SR (like 44100 or -often better- 48000 samples/second). This doesn't seem to be a common problem, but I have experienced it myself in one of my PCs. One would need a control loop (soundcard's output fed back into the input) to correct the output sampling rate, but this would make things overly complicated and thus it isn't implemented in Spectrum Lab (at least not directly). Also, if input and output sampling rate are "slightly different", it becomes a nightmare to manage the audio buffers so there is neither a sporadic input-overflow or output-underflow. Both cases of overflow cause an audible phase glitch in the output.
Much easier and more reliable to build a dedicated hardware, clocked by a 10 MHz reference, using a PLL, DDS, or similar.

All the best,
  Wolf .

Am 25.04.2012 11:38, schrieb Roger Lapthorn:
Peter,

I hope the experts like Wolf and Stefan can help.

Another question for Wolf etc: how would one use a single PC with two instances of SL running to (a) lock the soundcard to an 18-22kHz MSK signal like GBZ one one instance and then (b) generate a (frequency stable and locked)  output signal for an 8.970kHz TX?

It is some months since I have used SL and I was never what might be called an "expert user".

73s
Roger G3XBM





On 25 April 2012 10:12, PA1SDB, Peter <pa1sdb@amsat.org> wrote:
Hello VLF,
I like to do some local test here with Spectrum lab setings (and who knows, High ERP transmissions later  :-)
I have here a notebook that generates a signal with the Signal generator in Spectrum Lab at 8970.1 Hz.
It has a Loop connected at the input and thats how it is locked to a GDO (HWU, FTA, what is available)
I tried several, and that Lock wondow gets green, but output looks terrible.
To radiate the signal I use a pice of wire at the notebook LS output.
 
Below two grab's over the same periode of time.
My localy generated signal at 8970.100 Hz and for comparison the signal of DJ8WX at 8970.022 Hertz.
 
Both grab's are made with the same Spectrum Lab task.
 
Why does my signal look like a widband FM transmission ?
 
 
 
Best 73's, Peter - PA1SDB
 
 



--
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
https://sites.google.com/site/sub9khz/
http://qss2.blogspot.com/


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