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[195.171.43.25]) by mx.google.com with ESMTP id bn1si16330185wib.84.2013.12.29.04.09.27 for ; Sun, 29 Dec 2013 04:09:28 -0800 (PST) Received-SPF: neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) client-ip=195.171.43.25; Authentication-Results: mx.google.com; spf=neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) smtp.mail=owner-rsgb_lf_group@blacksheep.org; dkim=pass header.i=@mx.aol.com Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1VxEl6-0003dp-Gj for rs_out_1@blacksheep.org; Sun, 29 Dec 2013 11:42:16 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1VxEl5-0003dg-R1 for rsgb_lf_group@blacksheep.org; Sun, 29 Dec 2013 11:42:15 +0000 Received: from omr-d08.mx.aol.com ([205.188.109.207]) by relay1.thorcom.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.77) (envelope-from ) id 1VxEl3-0001x7-1t for rsgb_lf_group@blacksheep.org; Sun, 29 Dec 2013 11:42:14 +0000 Received: from mtaout-mbe02.mx.aol.com (mtaout-mbe02.mx.aol.com [172.26.254.174]) by omr-d08.mx.aol.com (Outbound Mail Relay) with ESMTP id 9F56C700028EF for ; Sun, 29 Dec 2013 06:42:10 -0500 (EST) Received: from White (95-91-238-155-dynip.superkabel.de [95.91.238.155]) by mtaout-mbe02.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id F21AC38000083 for ; Sun, 29 Dec 2013 06:42:09 -0500 (EST) Message-ID: <80BAE827E26041D293D7836651E4595A@White> From: "Markus Vester" To: References: <20C550A7D07741688C6A26E73CBCF741@White> <52BF4895.8080502@iup.uni-heidelberg.de> <52BF7E2A.9000002@iup.uni-heidelberg.de> <52BFD963.8020300@freenet.de> <8C09023FA2074CB380BC9CF1E7A514E3@White> <52C00514.4030805@freenet.de> Date: Sun, 29 Dec 2013 12:42:10 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 12.0.1606 X-MimeOLE: Produced By Microsoft MimeOLE V12.0.1606 x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20121107; t=1388317330; bh=PnUXflUQkaV86oc3DlnuQWtIklKJPOlFHq2Uj2WcTFM=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=APBpIFgGAecFa3NvSnwaxUwFB0FFfg5nGkp3CXml2XrSxiJEgXgMZqRvt9VLpjrDT IyMSEGWfcwuynAGpe8A21NCvyeWOkE7vizg6jtKm1eBhLLoAcdIfI/O7FdZoY68df+ efE/cqng32slxeEgtVkCRkc5Di5mo4pAE5vQCmIE= x-aol-sid: 3039ac1afeae52c00a911cc3 X-AOL-IP: 95.91.238.155 X-Spam-Score: 0.6 (/) 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: Ok Wolf, you're right. That is a simpler solution, requiring only minimal hardware changes for Stefan. One channel sends a continuous uninterrupted 17.94 kHz tone to the divider, the other channel conveys modulated Opera at an arbitrary frequency to a VOX rectifier. [...] Content analysis details: (0.6 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [205.188.109.207 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (markusvester[at]aol.com) -0.0 SPF_PASS SPF: sender matches SPF record -0.4 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid 1.0 FREEMAIL_REPLY From and body contain different freemails X-Scan-Signature: a1fa904463615545653fc893de869d24 Subject: Re: LF: VLF exciter Content-Type: multipart/alternative; boundary="----=_NextPart_000_000E_01CF0493.644EE770" 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_MESSAGE, MISSING_OUTLOOK_NAME 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 Status: O X-Status: X-Keywords: X-UID: 3166 Dies ist eine mehrteilige Nachricht im MIME-Format. ------=_NextPart_000_000E_01CF0493.644EE770 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ok Wolf, you're right. That is a simpler solution, requiring only minimal = hardware changes for Stefan. One channel sends a continuous = uninterrupted 17.94 kHz tone to the divider, the other channel conveys = modulated Opera at an arbitrary frequency to a VOX rectifier. Wolf, I'm looking forward to learn more details about your modulator and = MF PA setup when it's ready! Best 73, Markus From: wolf_dl4yhf=20 Sent: Sunday, December 29, 2013 12:18 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: VLF exciter Hello Markus, Ok .. i had assumed the problem was the flipflop (or binary frequency = divider) which would be in an unpredictable state when not fed with a = phase-coherent signal "in the gaps" (zeroes in the Opera- or whatever = amplitude keyed signal). This could be solved by providing the auxiliary output from the = soundcard (at 2 * f_tx), to keep the divider chain running. Depending on the MOSFET gate drivers, it may also be possible to feed = the 'keying signal' to an output-enable-signal, but I'm not sure if that = would put the driver output in high-impedance state (which would result = in a catastrophic 'bang' if both FET gates were left floating).=20 Anyway your suggestion with the xor gate may be the simpler variant than = using two different output signals from the soundcard. 73 and HNY, Wolf . (p.s. just managed to build a transformer for a low-voltage MF PA, which = transforms 0.6 Ohms drain load impedance to 12.5 Ohm with very low stray = inductance.. using copper foil instead of wire, and thin adhesive tape = ("Tesafilm") as insulator. But that's another story..) Am 29.12.2013 12:00, schrieb Markus Vester: Hi Wolf, I think Stefan was only trying to solve the simpler problem of = generating a dual squarewave drive for his VLF PA, and was not aiming = for amplitude modulated output yet. So when he transmits Opera we'll = just have to live with ultra-strong keyclicks, devastating the 9 kHz = band all over Europe ;-))=20 But I remember that in 2011 we discussed about transmitting = high-quality Hell piccies. As you say, the Kahn technique with a = separate AM modulator is certainly a good and efficient option. At VLF, = outphasing (aka Chireix or LINC technique) between two half-bridges = would be a valid alternative. There's some software for the purpose = (including Basic source code ;-) on=20 df6nm.bplaced.net/VLF/chirppix_outphase.zip This works in conjunction with your SndOutpt audio utility, generating = the two outphasing carriers at the left and right stereo output. Best 73, Markus (DF6NM) From: wolf_dl4yhf=20 Sent: Sunday, December 29, 2013 9:12 AM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: VLF exciter My suggestion: Use two outputs from the stereo soundcard:=20 An "amplitude" and a "phase" channel. The output from the phase = channel will be a square wave, coherent, constant amplitude, fed to the = divider chain. The "amplitude" channel delivers, well, the amplitude (as = a waveform with variable voltage) which, after rectification, drives the = final voltage via an additional mosfet. I think the software option is = already there, and iirc it has been used (by Jim ?) for an LF PA. This way, you could even use amplitude shaping if the bandwidth (from = the hard-keyed PA) was a problem - which I don't think it is, on VLF. Cheers, Wolf=20 (p.s. problem with the "very long command lines" already fixed, new = SL version will be uploaded soon). Am 29.12.2013 02:43, schrieb Stefan Sch=E4fer: Am 28.12.2013 23:33, schrieb Markus Vester:=20 [...]=20 PS Any progress on bypassing the divider in your VLF transmit = chain? Aaah, no, i forgot that. So i cannot transmit OP32 on VLF because it = would be incoherent then. So i have to key the PA via a VOX and OP32 = tones, still :-/ In this H bridge PA config, an exact 50% duty cycle isn't needed, so = i may actually remove the divider. But then i need a solid and defined = input signal wave form! How do i get an inverted signal then? A = transformer isn't possible since i like to have a wide frequency range = of the PA. So far it works from 10 Hz to > 100 kHz. With the frequency = divider, the wave form can be quite distorted, no problem unless the = peak reaches the necessary voltage level. So maybe it is better to build = the VOX circuit instead? Also i want to leave the PA circuit as it is, = for nostalgic reasons :-) Or do you have another idea? I remember that circuit with the XOR = gates... 73, Stefan/DK7FC ------=_NextPart_000_000E_01CF0493.644EE770 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Ok Wolf,
 
you're right. That=20 is a simpler solution, requiring only minimal hardware changes for = Stefan. One=20 channel sends a continuous uninterrupted 17.94 kHz tone to the = divider, the=20 other channel conveys modulated Opera at an arbitrary = frequency to=20 a VOX rectifier.
 
Wolf, I'm looking forward to learn more = details=20 about your modulator and MF PA setup when it's ready!
 
Best 73,
Markus
 
 

Sent: Sunday, December 29, 2013 12:18 PM
Subject: Re: LF: VLF exciter

Hello Markus,

Ok .. i had assumed = the problem=20 was the flipflop (or binary frequency divider) which would be in an=20 unpredictable state when not fed with a phase-coherent signal "in the = gaps"=20 (zeroes in the Opera- or whatever amplitude keyed signal).
This could = be=20 solved by providing the auxiliary output from the soundcard (at 2 * = f_tx), to=20 keep the divider chain running.
Depending on the MOSFET gate drivers, = it may=20 also be possible to feed the 'keying signal' to an output-enable-signal, = but I'm=20 not sure if that would put the driver output in high-impedance state = (which=20 would result in a catastrophic 'bang' if both FET gates were left = floating).=20

Anyway your suggestion with the xor gate may be the simpler = variant than=20 using two different output signals from the soundcard.

73 and=20 HNY,
  Wolf .

(p.s. just managed to build a transformer = for a=20 low-voltage MF PA, which transforms 0.6 Ohms drain load impedance to = 12.5 Ohm=20 with very low stray inductance.. using copper foil instead of wire, and = thin=20 adhesive tape ("Tesafilm") as insulator. But that's another=20 story..)


Am 29.12.2013 12:00, schrieb Markus = Vester:
Hi Wolf,
 
I think Stefan was only trying to = solve the=20 simpler problem of generating a dual squarewave drive for his VLF PA, = and was=20 not aiming for amplitude modulated output yet. So when he transmits = Opera=20 we'll just have to live with ultra-strong keyclicks, devastating the 9 = kHz=20 band all over Europe ;-)) 
 
But I remember that in 2011 we = discussed about=20 transmitting high-quality Hell piccies. As you say, the Kahn = technique with a separate AM modulator is certainly a good and = efficient=20 option. At VLF, outphasing (aka Chireix or LINC technique) = between two=20 half-bridges would be a valid alternative. There's some software for = the=20 purpose (including Basic source code ;-) on
df6nm.bplaced.net/VLF/chirppix_outphase.zip<= /FONT>
This works in conjunction = with your SndOutpt=20 audio utility, generating the two outphasing carriers at the left and = right=20 stereo output.
 
Best 73,
Markus (DF6NM)

From: wolf_dl4yhf
Sent: Sunday, December 29, 2013 9:12 AM
To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: VLF exciter

My suggestion:

Use two outputs = from the=20 stereo soundcard:
An "amplitude" and a "phase" channel. The output = from=20 the phase channel will be a square wave, coherent, constant amplitude, = fed to=20 the divider chain. The "amplitude" channel delivers, well, the = amplitude (as a=20 waveform with variable voltage) which, after rectification, drives the = final=20 voltage via an additional mosfet. I think the software option is = already=20 there, and iirc it has been used (by Jim ?) for an LF PA.
This way, = you=20 could even use amplitude shaping if the bandwidth (from the hard-keyed = PA) was=20 a problem - which I don't think it is, on = VLF.

Cheers,
  Wolf=20

 (p.s. problem with the "very long command lines" already = fixed,=20 new SL version will be uploaded soon).

Am 29.12.2013 02:43, = schrieb=20 Stefan Sch=E4fer:

Am 28.12.2013 23:33, schrieb Markus Vester:=20
[...]=20
 
PS Any progress on bypassing the = divider in=20 your VLF transmit chain?

Aaah, no, i forgot that. So i cannot transmit OP32 = on VLF=20 because it would be incoherent then. So i have to key the PA via a = VOX and=20 OP32 tones, still :-/

In this H bridge PA config, an exact = 50% duty=20 cycle isn't needed, so i may actually remove the divider. But then i = need a=20 solid and defined input signal wave form! How do i get an inverted = signal=20 then? A transformer isn't possible since i like to have a wide = frequency=20 range of the PA. So far it works from 10 Hz to > 100 kHz. With = the=20 frequency divider, the wave form can be quite distorted, no problem = unless=20 the peak reaches the necessary voltage level. So maybe it is better = to build=20 the VOX circuit instead? Also i want to leave the PA circuit as it = is, for=20 nostalgic reasons :-)
Or do you have another idea? I remember = that=20 circuit with the XOR gates...

73,=20 = Stefan/DK7FC


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