[linux-dvb] HVR-1800 failing to detect any QAM256 channels

[Michael Krufky]

2008/4/30 Eric Cronin <ecronin at gizmolabs.org>:
>  I have an HP Pavilion OEM'd HVR-1800 that I'm giving a shot at getting
> working (PVR-500 and HDHR are my production analog/digital inputs).
>
>  I'm running Mythbuntu 8.04 and have tried both with the bundled version of
> v4l-dvb modules and a hg copy from April 29, and both have the same problem:
>
>  The card is detected fine and /dev/dvb/* created.  When I run 'scan
> us-Cable-Standard-center-frequencies-QAM256' it detects nothing, even on
> frequencies which I know are QAM256 from the HDHR which is 12" of coax away
> from the HVR-1800.  Here is an example from the HDHR scan:
>
>  SCANNING: 759000000 (us-cable:118, us-irc:118)
>  LOCK: qam256 (ss=90 snq=52 seq=100)
>  PROGRAM: 1: 6.1 WPVI-HD
>  PROGRAM: 2: 10.1 WCAU-DT
>  PROGRAM: 3: 6.2 WPVI-SD
>  PROGRAM: 4: 6.3 WPVI-WX
>  PROGRAM: 5: 10.2 WX-PLUS
>
>  and from 'scan -v test-chan118' which has just 759000000 in it:
>
>  scanning test-chan118
>  using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
>  >>> tune to: 759000000:QAM_256
>  >>> tuning status == 0x00
>  >>> tuning status == 0x00
>  >>> tuning status == 0x00
>  >>> tuning status == 0x00
>  >>> tuning status == 0x00
>  >>> tuning status == 0x00
>  >>> tuning status == 0x00
>  >>> tuning status == 0x00
>  >>> tuning status == 0x00
>  >>> tuning status == 0x00
>  WARNING: >>> tuning failed!!!
>  >>> tune to: 759000000:QAM_256 (tuning failed)
>  >>> tuning status == 0x00
>  >>> tuning status == 0x00
>  >>> tuning status == 0x00
>  >>> tuning status == 0x00
>  >>> tuning status == 0x00
>  >>> tuning status == 0x00
>  >>> tuning status == 0x00
>  >>> tuning status == 0x00
>  >>> tuning status == 0x00
>  >>> tuning status == 0x00
>  WARNING: >>> tuning failed!!!
>  ERROR: initial tuning failed
>  dumping lists (0 services)
>  Done.
>
>  I have checked the physical connections best I can.  Connecting the
> HVR-1800's coax to the PVR-500 sees the analog side of things fine, and the
> correct jack on the HVR-1800 is being used.
>
>  I'm not sure where to go from here debugging things, any suggestions or
> more data I can provide?  The modprobe-produced info from dmesg is at the
> end of this message.


Eric,

When you use the scan command to scan for QAM channels, you must
specify -a2, to signify that you are scanning digital cable.

Try that -- does that work?

-Mike