Return-Path: Received: (qmail 25385 invoked from network); 28 Jan 2002 00:05:34 -0000 Received: from unknown (HELO warrior.services.quay.plus.net) (212.159.14.227) by excalibur-qfe1-smtp-plusnet.harl.plus.net with SMTP; 28 Jan 2002 00:05:34 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 3075 invoked from network); 28 Jan 2002 00:05:33 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by warrior.services.quay.plus.net with SMTP; 28 Jan 2002 00:05:33 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 16UzFU-0006Tb-00 for rsgb_lf_group-outgoing@blacksheep.org; Mon, 28 Jan 2002 00:02:12 +0000 Received: from imo-d07.mx.aol.com ([205.188.157.39]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 16UzFT-0006TR-00 for rsgb_lf_group@blacksheep.org; Mon, 28 Jan 2002 00:02:11 +0000 Received: from G0MRF@aol.com by imo-d07.mx.aol.com (mail_out_v31_r1.26.) id l.d6.11498bf0 (4257) for ; Sun, 27 Jan 2002 19:00:45 -0500 (EST) From: G0MRF@aol.com Message-ID: Date: Sun, 27 Jan 2002 19:00:45 EST Subject: Re: LF: Jason Tests / PSK31 To: rsgb_lf_group@blacksheep.org MIME-Version: 1.0 Content-Type: text/html; charset=windows-1252 X-Mailer: AOL 6.0 for Windows UK sub 10510 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Content-transfer-encoding: 8bit In a message dated 1/27/02 4:34:34 PM GMT Standard Time, DL4YHF@aol.com writes:

Hello Jim and David,

I have modified the PSK31 core in Spectrum Lab a bit so it can now produce an on/off keyed "audio carrier" with a few kHz which only needs to be rectified to have the raw phase keying information.

What I did not understand completely is how Jim produces the amplitude shaping. I think the PA supply voltage is variable, but where does the "envelope" signal come from ? One could (with a bit more programming work and more CPU power) deliver the "pulse shaping envelope" on the second channel of a stereo card.

73 Wolf DL4YHF.

Hello Wolf.

Not sure about Jim's system. Best let him answer.
However, The SM6LKM/G0MRF DDS has an input pin that allows a DC voltage to control the output level and phase. ( A balanced modulator using 2 diodes)
With half the supply rail (lets say 6 Volts) on the pin, the RF output is zero.
As the voltage is increased towards 12V the output increases in proportion.
If the voltage is decreased from 6V towards zero then the RF output also increases in proportion, but with the opposite phase.

So 6V = no output.
> 6 V = phase 0 degrees
< 6V = -180 degrees

A potentially good idea when we designed it, but lacking an application.

Thanks

David G0MRF