[linux-dvb] Fine tuning app ?

Glenn McGrath glenn.l.mcgrath at gmail.com
Thu Sep 4 07:04:11 CEST 2008


On Thu, Sep 4, 2008 at 12:01 AM, Michael Krufky <mkrufky at linuxtv.org> wrote:
> Glenn McGrath wrote:
>> It would be really useful to have a fine tuning app that can use a
>> table of hard coded frequency values  for different countries and fine
>> tune it until the error rate is minimal.
>
> w_scan -- http://wirbel.htpc-forum.de/
>
> ...now with ATSC / QAM Annex-B tuning support!

I didnt realise w_scan did fine tuning... ill try and describe my
situation some more.

First off, w_scan didnt find any channels, i realised it was looking
at the wrong frequencies, so i modified w_scan to check the center
frequency specified by Australian (where i live) regulations, w_scan
only found 1 or 5 station.

I did a lot of digging and found i need to check somewhere within
125kHz of the center frequency (usually center +125kHz is best), if i
just check the center frequency my tv card doesnt even get a lock.

A nice piece of info i found from
http://www.acma.gov.au/webwr/_assets/main/lib100059/geninfo.pdf
---
The centre frequency of the digital television channel is shown in the
service listings in this
book. It should be noted that for implementation reasons, broadcasters
may choose to operate
with a +/- 125 kHz offset from the nominal channel centre frequency.
---

I am still confused about w_scan vs scan, if i do w_scan -x and then
use scan, is scan supposed to do some fine tuning ?  I so see it
trying different frequencies (sometimes very strange frequencies), no
quite sure whats going on.

Also, is this the best place to talk about w_scan or is there a
specific project list ?


Thanks

Glenn



More information about the linux-dvb mailing list