Hi After reading that the Hauppauge Nova-T 500 seemed stable, I recently upgraded from a rather old Twin MiniTer DVT DVB-T card to a Nova-T 500 to get the dual tuner. However I'm experiencing some problems with the card. I'm based in Melbourne, Australia where we have 5 main digital free to air channels. 3 of them work fine (Seven, Nine, Ten), but 2 of them (ABC, SBS) cause strange and intermittent problems. Basically the channels ABC & SBS *sometimes* work perfectly fine, but other times are completely choppy and broken. Particularly strange is that you can record a program on ABC/SBS (i use mythtv), get a completely choppy and unwatchable stream and then then record another program _immediately_ after it with a 1 minute gap on the same channel, and it will be fine. It's as if the card sometimes locks badly on the signal and won't fix itself, but changing away and back to the channel again can make it fix itself. Now my initial reaction was that it's a signal problem, but a number of things suggest that's not really the case. Adding/removing a line amplifier changes the reported signal strength, but doesn't change the problem. All other 3 channels are fine, just ABC/SBS give intermittent problems still. Turning on/off the LNA setting also changes the reported signal strength, but also doesn't change the problem. In mythtv even with the LNA off the 3 normal channels work fine, just ABC/SBS have the exact same strange and intermittent problem still. I thought it might be a tuner delay issue, so I set the "DVB Tuning Delay (msec)" in mythtv to 150, but that didn't help either. Doing some more searching, I came across some interesting posts in an MCE forum. Basically it seems the MCE users in Australia were having the exact same problem with Nova-T 500 cards last year. All channels fine except ABC/SBS in Melbourne and some regional areas specifically. Now a couple of posts suggest that this was actually a DiBcom chipset driver issue: http://www.xpmediacentre.com.au/community/tuners-mce/12244-hauppage-nova-t-500-driver-bug-19.html#post118420 --- - The problem with tuning to ABC and SBS is due to the DiBcom chipset having problems with the Australian 7mHz bandwidth (most of the world use 8mHz). This affects all card brands with this cipset... its just the NovaT500 is the most popular one. - DiBcom shipped a diagnostic device to ? (New Magic?) for testing the card. Testing has been done all round Melbourne (and other cities?) and the data collected sent to DiBcom. - New Magic are currently testing an updated DiBcom firmware. It might be released soon, maybe end of the week, if a deployment process can be devised. Currently, the upgrade process is "convoluted". --- If you read in the next couple of posts on that page, you'll see that users report that an updated driver package did fix the problem for a lot of users. And there's this post from "New Magic Australia", the Nova-T 500 card distributor in Australia I believe. http://www.xpmediacentre.com.au/community/tuners-mce/12244-hauppage-nova-t-500-driver-bug-20.html#post120121 --- After many months of almost daily effort we are happy to announce that we have a release candidate update for the Nova 500 card, to fix the issues on ABC and SBS (and other services) in some parts of Melbourne and some regional areas. At this stage it's a release candidate but already many users who have been given the update for testing are reporting great results. ... For those interested the issue actually had nothing to do with Hauppauge, but rather was a chipset issue which we have identified in other tuner and set-top products. Because the issue is unique to only small parts of Australia, many users and manufacturers write the symptoms off as a reception problem. Once a final firmware/driver update is released, anyone interested in the technical details can contact me for more info. --- So basically I'm wondering if this particular problem was fixed for MCE users by an updated windows driver, but hasn't been fixed in the linux v4l code tree. If it hasn't been fixed in the linux tree, I'm wondering what the best way to try and debug and fix this is. It seems a rather annoying edge case, but obviously it's caused me a lot of headaches :) Thanks in advance Rob cc'd pboettcher@xxxxxxxxx and ademol@xxxxxxxxx as they're listed in the dib*.{h,c} files as the main authors, and patrick.boettcher@xxxxxxx from the current firmware download page in the hope they can shed some light... _______________________________________________ linux-dvb mailing list linux-dvb@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
