Return-Path: Received: (qmail 14540 invoked from network); 10 May 2000 13:13:17 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by bells.core.plus.net.uk with SMTP; 10 May 2000 13:13:17 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 12pWBr-0001on-00 for rsgb_lf_group-outgoing@blacksheep.org; Wed, 10 May 2000 14:06:15 +0100 X-Priority: 3 X-MSMail-Priority: Normal Received: from imo15.mx.aol.com ([152.163.225.5]) by post.thorcom.com with esmtp (Exim 3.02 #1) id 12pWBo-0001oe-00 for rsgb_lf_group@blacksheep.org; Wed, 10 May 2000 14:06:13 +0100 Received: from G0MRF@aol.com by imo15.mx.aol.com (mail_out_v26.7.) id l.e6.531c011 (3890) for ; Wed, 10 May 2000 09:05:17 -0400 (EDT) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 From: G0MRF@aol.com Message-ID: Date: Wed, 10 May 2000 09:05:17 EDT Subject: Re: LF: DDS Source board (was DFCW parameters) To: rsgb_lf_group@blacksheep.org MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 8bit X-Mailer: AOL 5.0 for Windows sub 32 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: In a message dated 5/10/00 12:14:48 PM GMT Daylight Time, ACTALBOT@dera.gov.uk writes: << WINDOZE programming makes it more difficult to address PC I/O ports directly than was DOS. Dave 'MRF, when you say linear BPSK what do you mean ? There is no option to shape the waveform surely with only 0 / 180 and no signal states. >> Andy. Sorry, "linear" in this context..... A BPSK Input pin Which: When presented with a DC voltage equivalent to half the supply line voltage will result in a balanced condition producing zero RF output. Changing the voltage on the BPSK input pin slowly from eg 6V to 12V will generate a slowly increasing level of Q output which reaches a maximum at 12V. i.e. The instantaneous amplitude of the output is proportional to the instantaneous voltage on the BPSK input pin. Hence you can control the rise / fall times / waveshaping by accuratly shaping the voltage applied to the BPSK input. Changing from half rail to 0V produces the opposite phase. (not Q) Sorry this is such a long reply. I didn't have time to write a short one. 73 David