From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-wy0-f174.google.com ([74.125.82.174]:45137 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755615Ab1I3SFT (ORCPT ); Fri, 30 Sep 2011 14:05:19 -0400 Received: by wyg34 with SMTP id 34so1340609wyg.19 for ; Fri, 30 Sep 2011 11:05:18 -0700 (PDT) Message-ID: <4E8604DA.2070008@gmail.com> Date: Fri, 30 Sep 2011 19:05:14 +0100 From: Malcolm Priestley MIME-Version: 1.0 To: linux-media@vger.kernel.org, simon.farnsworth@onelan.com Subject: Re: Problems tuning PAL-D with a Hauppauge HVR-1110 (TDA18271 tuner) - workaround hack included References: <201109281350.52099.simon.farnsworth@onelan.com> In-Reply-To: <201109281350.52099.simon.farnsworth@onelan.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 28/09/11 13:50, Simon Farnsworth wrote: > (note - the CC list is everyone over 50% certainty from get_maintainer.pl) > > I'm having problems getting a Hauppauge HVR-1110 card to successfully > tune PAL-D at 85.250 MHz vision frequency; by experimentation, I've > determined that the tda18271 is tuning to a frequency 1.25 MHz lower > than the vision frequency I've requested, so the following workaround > "fixes" it for me. Are you sure the transmitter concerned doesn't have a VSB filter for an adjacent DVB-T digital transmitter? VSB fitlers have been used on UK(PAL-I) transmitters for some time. From downloads.bbc.co.uk/rd/pubs/whp/whp-pdf-files/WHP023.pdf "To avoid the likelihood of PAL-I interference to DTT transmissions, the proposal is to use a System B/G VSB filter which provides at least 30 dB of sideband attenuation at 1.4 MHz below the vision carrier. It is also necessary to reduce the image sidebands resulting from transmitter non-linearity, and the method is to fit a high-order bandpass filter at the transmitter output. Typically, the overall sideband response will be -2 dB at (fv - 0.75) MHz and -20 dB at (fv - 1.25) MHz, where fv is the frequency of the vision carrier."