Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mg02.r1000.mx.aol.com (Internet Inbound) with ESMTP id 1A49838000090; Fri, 12 Oct 2012 14:27:31 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1TMjIj-0005zz-HW for rs_out_1@blacksheep.org; Fri, 12 Oct 2012 18:45:33 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1TMjIi-0005zq-Rj for rsgb_lf_group@blacksheep.org; Fri, 12 Oct 2012 18:45:32 +0100 Received: from relay2.uni-heidelberg.de ([129.206.210.211]) by relay1.thorcom.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.77) (envelope-from ) id 1TMjIf-0004m8-TR for rsgb_lf_group@blacksheep.org; Fri, 12 Oct 2012 18:45:31 +0100 Received: from freitag.iup.uni-heidelberg.de (freitag.iup.uni-heidelberg.de [129.206.29.204]) by relay2.uni-heidelberg.de (8.13.8/8.13.8) with ESMTP id q9CHjS8Y011291 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Fri, 12 Oct 2012 19:45:29 +0200 Received: from [129.206.22.206] (pc206.iup.uni-heidelberg.de [129.206.22.206]) by freitag.iup.uni-heidelberg.de (8.12.11.20060308/8.11.2) with ESMTP id q9CHjSOG024569 for ; Fri, 12 Oct 2012 19:45:28 +0200 Message-ID: <5078572E.3070508@iup.uni-heidelberg.de> Date: Fri, 12 Oct 2012 19:45:18 +0200 From: =?ISO-8859-15?Q?Stefan_Sch=E4fer?= User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <50783F5D.60809@iup.uni-heidelberg.de> <50784744.5020705@psk31.plus.com> In-Reply-To: <50784744.5020705@psk31.plus.com> X-Spam-Score: -4.4 (----) 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 Eddie, :-) Aah, i missed that humor... Your circuit looks much more presentable than mine though! Furthermore this table is not the place where i built the circuit. That place is 20m lower in the building and the table probably looks similar to yours :-) [...] Content analysis details: (-4.4 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, medium trust [129.206.210.211 listed in list.dnswl.org] -2.1 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message X-Scan-Signature: 9cafc73d135491d75f4f47d39ed43841 Subject: Re: LF: WSPR on the 630m band Content-Type: multipart/alternative; boundary="------------010006030009000907090803" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=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-sid: 3039ac1d60ca507861121116 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. --------------010006030009000907090803 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by relay2.uni-heidelberg.de id q9CHjS8Y011291 Hi Eddie, :-) Aah, i missed that humor... Your circuit looks much more presentable than mine though! Furthermore=20 this table is not the place where i built the circuit. That place is 20m=20 lower in the building and the table probably looks similar to yours :-) BTW, sorry that i can't try to decode you now. There have been hardware=20 changes so i am limited to the range of 461...485 kHz now... We have to=20 wait these few weeks i'm afraid... Anyway, good luck!! Best 73, Stefan/DK7FC Am 12.10.2012 18:37, schrieb g3zjo: > Hi Stefan > > I see what you mean, so we have both been at it, (upsetting Mal some=20 > more). :-) > > What a beautiful clear clean bench surface you have, I had to=20 > carefully frame my pictures after pushing aside the clutter. > > http://photobucket.com/albums/dd243/radiotalk/xbmxvtr500ksml.jpg > > 73 > > Eddie G3ZJO > > > > On 12/10/2012 17:03, Stefan Sch=E4fer wrote: >> MF! >> >> Last night i built a transmit converter which allows me to transmit=20 >> *WSPR on 630m* now. >> >> Yes yes yes yes yes Mal, CW is preferred! But many OMs go to bed=20 >> quite early i find. Not so their PCs, they run over night, and so my=20 >> transmitter will do this weekend if all goes right. :-) I'm not=20 >> present in the shack anyway, so no chance for CW... >> >> I'm using _*normal WSPR*_, not the slow versions. >> >> Right now the first tests are running and i check if the system=20 >> becomes to warm. >> >> The design of this mixer is quite chaotic but i like it :-) It is a=20 >> modular system...: First, a tone of 14700 Hz is generated by the WSPR=20 >> program. Is is decoupled from anything by an audio isolating=20 >> transformer. This signal is applied to a SA612 mixer. The LO (461=20 >> kHz) in this test setup comes fom my DDS VFO which is used in the=20 >> first VLF experiments. The output looks very well as expected on the=20 >> scope. Filtering of mixing products is done in my MF meachanical=20 >> filter which is use in front of the receiver normally! I've published=20 >> the nearly perfect filter curve some weeks ago. Of course the sine=20 >> wave coming out from the filter looks very well! This sine wave is=20 >> applied to an OP AMP which is switched as a comparator. I've added a=20 >> small hysteresis (10 MOhm / 47k) to prevent an oscillating output=20 >> when there is no input signal. Works well! The output of the OP AMP=20 >> is fed to a ICL7667 (FET driver) which makes a low impedant output.=20 >> In series with 1 Ohm and 1 uF this rectanfgular waveform is applied=20 >> to a small ferrite toroid with a trifilar winding. So this output is=20 >> again galvanically decoupled from the circuit and provides an=20 >> opposite phase rectangular signal at 475.7 kHz. >> Since my PA was/is designed to have a 4f input (1900 kHz -> 475 kHz=20 >> out) i had to make a tap behind the divider, so i have to take care=20 >> to maintain the 50 % duty cycle in the new circuit. The new external=20 >> drive signal from the converter is applied by a simple headphone=20 >> jack/plug! I actually found a 3.5mm stereo-jack with dimensions 10mm=20 >> x 5mm and also found a few holes to add this on the board. So the PA=20 >> is now able to run as before and additionally with this new=20 >> converter...... >> >> The AF signal levels and the LO signal level is critical. Choosing=20 >> wrong values will change the 50% duty cycle which will quickly kill=20 >> the FETs in this PA design. So i'm using an old modified PC power=20 >> supply that will shut down quickly if the current exceeds a certain=20 >> limit... >> >> After writing this email the PA became hand warm so it looks all=20 >> fine. I will go down to 50% TX duty cycle now and even receive during=20 >> the breaks in WSPR. However the MF filter is now used for the TX so=20 >> the RX performance may be slightly lowered... >> >> *Reports about my transmissions on 475.700 kHz are very welcomed. I'm=20 >> also receiving and uploading to the WSPR database... >> Maybe i will run the test until monday :-)* >> >> Best 73, Stefan/DK7FC >> >> PS: https://dl.dropbox.com/u/19882028/MF/stuff.JPG >> >> No virus found in this message. >> Checked by AVG - www.avg.com >> Version: 2012.0.2221 / Virus Database: 2441/5327 - Release Date: 10/12= /12 >> > --------------010006030009000907090803 Content-Type: text/html; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by relay2.uni-heidelberg.de id q9CHjS8Y011291 Hi Eddie,

:-) Aah, i missed that humor...

Your circuit looks much more presentable than mine though! Furthermore this table is not the place where i built the circuit. That place is 20m lower in the building and the table probably looks similar to yours :-)

BTW, sorry that i can't try to decode you now. There have been hardware changes so i am limited to the range of 461...485 kHz now... We have to wait these few weeks i'm afraid...

Anyway, good luck!!

Best 73, Stefan/DK7FC

Am 12.10.2012 18:37, schrieb g3zjo:
Hi Stefan

I see what you mean, so we have both been at it, (upsetting Mal some more). :-)

What a beautiful clear clean bench surface you have, I had to carefully frame my pictures after pushing aside the clutter.

http://photobucket.com/albums/dd243/radiotalk/xbmxvtr500ksml.jpg
73

Eddie G3ZJO



On 12/10/2012 17:03, Stefan Sch=E4fer wrote:
MF!

Last night i built a transmit converter which allows me to transmit WS= PR on 630m now.

Yes yes yes yes yes Mal, CW is preferred! But many OMs go to bed quite early i find. Not so their PCs, they run over night, and so my transmitter will do this weekend if all goes right. :-) I'm not present in the shack anyway, so no chance for CW...

I'm using normal WSPR, not the slow versions.

Right now the first tests are running and i check if the system becomes to warm.

The design of this mixer is quite chaotic but i like it :-) It is a modular system...: First, a tone of 14700 Hz is generated by the WSPR program. Is is decoupled from anything by an audio isolating transformer. This signal is applied to a SA612 mixer. The LO (461 kHz) in this test setup comes fom my DDS VFO which is used in the first VLF experiments. The output looks very well as expected on the scope. Filtering of mixing products is done in my MF meachanical filter which is use in front of the receiver normally! I've published the nearly perfect filter curve some weeks ago. Of course the sine wave coming out from the filter looks very well! This sine wave is applied to an OP AMP which is switched as a comparator. I've added a small hysteresis (10 MOhm / 47k) to prevent an oscillating output when there is no input signal. Works well! The output of the OP AMP is fed to a ICL7667 (FET driver) which makes a low impedant output. In series with 1 Ohm and 1 uF this rectanfgular waveform is applied to a small ferrite toroid with a trifilar winding. So this output is again galvanically decoupled from the circuit and provides an opposite phase rectangular signal at 475.7 kHz.
Since my PA was/is designed to have a 4f input (1900 kHz -> 475 kHz out) i had to make a tap behind the divider, so i have to take care to maintain the 50 % duty cycle in the new circuit. The new external drive signal from the converter is applied by a simple headphone jack/plug! I actually found a 3.5mm stereo-jack with dimensions 10mm x 5mm and also found a few holes to add this on the board. So the PA is now able to run as before and additionally with this new converter......

The AF signal levels and the LO signal level is critical. Choosing wrong values will change the 50% duty cycle which will quickly kill the FETs in this PA design. So i'm using an old modified PC power supply that will shut down quickly if the current exceeds a certain limit...

After writing this email the PA became hand warm so it looks all fine. I will go down to 50% TX duty cycle now and even receive during the breaks in WSPR. However the MF filter is now used for the TX so the RX performance may be slightly lowered...

Reports about my transmissions on 475.700 kHz are very welcomed. I'm also receiving and uploading to the WSPR database...
Maybe i will run the test until monday :-)

Best 73, Stefan/DK7FC

PS: https://dl.dropb= ox.com/u/19882028/MF/stuff.JPG

No virus = found in this message.
Checked by AVG - = www.avg.com
Version: 2012.0.2221 / Virus Database: 2441/5327 - Release Date: 10/12/12


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