Return-Path: Received: (qmail 18922 invoked from network); 3 Feb 2004 21:54:37 -0000 Received: from unknown (HELO ptb-mxscan02.plus.net) (212.159.14.236) by ptb-mailstore03.plus.net with SMTP; 3 Feb 2004 21:54:37 -0000 Received: (qmail 51411 invoked from network); 3 Feb 2004 21:54:37 -0000 X-Filtered-by: Plusnet (hmail v1.01) X-Spam-detection-level: 11 Received: from ptb-mxcore02.plus.net (212.159.14.216) by ptb-mxscan02.plus.net with SMTP; 3 Feb 2004 21:54:36 -0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore02.plus.net with esmtp (Exim) id 1Ao8V9-000DFb-Vu for dave@picks.force9.co.uk; Tue, 03 Feb 2004 21:54:36 +0000 X-Fake-Domain: majordom Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Ao8Ts-0001Oo-1B for rs_out@blacksheep.org; Tue, 03 Feb 2004 21:53:16 +0000 Received: from [194.73.73.148] (helo=zinc.btinternet.com) by post.thorcom.com with esmtp (Exim 4.14) id 1Ao8Tr-0001Of-Gb for rsgb_lf_group@blacksheep.org; Tue, 03 Feb 2004 21:53:15 +0000 Received: from [213.122.3.235] (helo=Main) by zinc.btinternet.com with smtp (Exim 3.22 #25) id 1Ao8Tq-0002F5-00 for rsgb_lf_group@blacksheep.org; Tue, 03 Feb 2004 21:53:15 +0000 X-Bad-Message-ID: no DNS (Main) Message-ID: <001701c3eaa0$1e8670e0$6507a8c0@Main> From: "Alan Melia" To: rsgb_lf_group@blacksheep.org References: Date: Tue, 3 Feb 2004 21:52:31 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Subject: LF: Re: RE: Re: Re: G0MRF 300w Tx & DDS VFO Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Checker-Version: SpamAssassin 2.60 (1.212-2003-09-23-exp) on post.thorcom.com X-Spam-Status: No, hits=0.0 required=5.0 tests=none autolearn=no version=2.60 X-SA-Exim-Scanned: Yes Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-PN-SPAMFiltered: yes X-Spam-Rating: 2 Yes Ok Gary, I guessed it was so. I just wondered whther you had a "tight" filter. The signal out of the chip (do be carefull here) should be a logic level ..i.e. 5v p-p I would have thought (??) Cheers de Alan G3NYK ----- Original Message ----- From: "G4WGT - Gary" To: Sent: 03 February 2004 20:01 Subject: LF: RE: Re: Re: G0MRF 300w Tx & DDS VFO > Hi Alan & LF, > > Thanks for the advise, but I did realise that the input is x2 ie. 274 Khz, > it's just that when testing the DDS VFO with the scope on the bench I did > the checks at those freq's mentioned. It is still no different at 274 Khz, > in fact at its best (15Mhz) it is only producing 300mV P-P & not the > expected 1V P-P. > > The sig comes out of the DDS IC thro' a 2 pole LPF to a buffer amp IC, the > sig is even lower at the unbuffered output(before the IC). I will have to > remove it from its case to trace back thro' the components. > > I will keep you posted > > 73 > > Gary - G4WGT > > > > -----Original Message----- > From: owner-rsgb_lf_group@blacksheep.org > [mailto:owner-rsgb_lf_group@blacksheep.org]On Behalf Of Alan Melia > Sent: 02 February 2004 22:12 > To: rsgb_lf_group@blacksheep.org > Subject: LF: Re: Re: G0MRF 300w Tx & DDS VFO > > > Hi Gary Ah you need 274kHz for the feed to the EXT pin it goes to the input > of a divide by two to give square wave drive to the PA stage. Still you > should be getting more than that out of it. It sounds as though something is > not right...50mV is far too low. Is there a LPF on the output?? It may be > that there is a component problem there. > > Cheers de Alan G3NYK > >