[mythtv] Problems with Hauppauge Nova TD Dual Tuner USB Stick and Mythtv, no problems in Windows! (Another Sillyname)

Tue Apr 16 07:18:32 UTC 2013

May be useful if I just throw in my experiences with this card in 
Australia.  I have two of these cards, and for a long time they 
performed poorly, exhibiting the dreaded zero byte recordings followed 
by consistent failure for that tuner to record anything further until a 
cold restart of the card.  Given this was happening every 12-24 hours, 
it was frustrating to say the least.

I have a mast head amplifier, so most signals are pretty strong.  As 
noted elsewhere on the Internet, SBS and ABC were the channels most 
affected.

I have nearly completely resolved these issues by:

1) disabling LNA activation
2) enabling the buggy_sfn_workaround flag
3) forcing no suspension of USB devices

My /etc/modprobe.d/dib0700.conf file looks like this:

> options dvb_usb_dib0700 force_lna_activation=0
> options dib3000mc buggy_sfn_workaround=1
> options usbcore autosuspend=-1

And I modified the kernel boot options for usb autosuspend also.

Since these changes I have had one tuner lock up (with 8 tuners) in four
weeks now.

Cheers,

Charlie

On 11/04/13 20:00, mythtv-dev-request at mythtv.org wrote:
> Message: 2
> Date: Thu, 11 Apr 2013 09:39:37 +0100
> From: Another Sillyname <anothersname at googlemail.com>
> To: Development of MythTV <mythtv-dev at mythtv.org>,
> 	linux-media at vger.kernel.org
> Subject: Re: [mythtv] Problems with Hauppauge Nova TD Dual Tuner USB
> 	Stick and Mythtv, no problems in Windows!
> Message-ID:
> 	<CAOS+5GGurXPcEumPLfdDxwos2Yi41aSXfPE_zfwfLq=MWkVzAQ at mail.gmail.com>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Further to my previous E-Mail on this I've now done a LOT more
> investigation and am posting this message for feedback and to alert anyone
> interested where you might get some issues.
>
> The location where this chap is unfortunately right in a dead spot for the
> Crystal Palace transmitters.....
>
> Normally he would pull ALL his feeds from Crystal Palace on
frequencies....
>
> 482Mhz
> 490Mhz
> 506Mhz
> 514Mhz
> 545.8Mhz (HD Mux)
> 529.8Mhz
>
> However Crystal Palace does not give him a good signal on some of the
Muxes
> and I couldn't work out why, eventually (after going up to his roof) I
> realised that he didn't have clear line of site to the transmitter tower
> and incredibly although the top of the tower was just about visible
through
> a small gap in between two blocking buildings he could only see maybe the
> top 20% of the tower even then.
>
> My guess is that the different muxes are transmitting from different
> physical transmitters at slightly different heights on the tower and as a
> consequence he 'appears' to get a very strong and clear signal on some
> muxes and no lock on others.  Just to add further confusion Canary Wharf
is
> only at about a 6% offset from his line of site to the tower and his view
> of it is unobstructed so the possibility of reflected signals could exist
> (I couldn't understand why sometimes doing a tune I'd get the correct
> channels on say Channel 23 (490Mhz) and then the same channels apparently
> repeated on Channel 24 offset 1 or 2, as they had the same TID mythtv just
> couldn't identify them cleanly.
>
> This meant he had to use one of the alternate transmitters from either
> Poplar or Alexandra Palace for some signals.
>
> However after playing around yesterday I'm now starting to think that the
> Hauppauge DVB-TD Stick tuners are not great at switching from a very
strong
> signal coming in from one mux and a much weaker signal coming in from a
> different mux bloom to switch channels between.
>
> For example AlyPaly transmits on frequencies....
>
> 698Mhz
> 770Mhz
> 738Mhz (HD Mux)
>
> It has far fewer channels in it's Digital Bloom so you end up having to
mix
> and match some (that you can get) from Crystal Palace and some from
> AlyPaly, however the tuners don't seem to like changing channels across
the
> different muxes, once on a specific transmitter changing channels is
> consistent within the mux but changing to the other transmitter is a bit
> hit and miss....and I guess this is perhaps signal strength related?
>
> My supposition is that either the DVB driver or Myth is 'seeing' the lock
> and then setting a level for the expected signal strength, when the other
> transmitter comes in at a different strength the tuning gets confused and
> can't lock properly.
>
> I hope the above makes some kind of sense and would appreciate any
thoughts
> or comments people have, I may end up suggesting to him that he may have
to
> just get a better TV antenna on his roof that's raised above the blocking
> building.....
>
>
>
>
> On 28 March 2013 21:14, Another Sillyname
<anothersname at googlemail.com>wrote:
>
>> Thanks Mike, there was a bug in the original driver.......you may want
>> to read this thread
>>
>> http://www.mythtv.org/pipermail/mythtv-users/2013-February/346602.html
>>
>> I hadn't realised I've been trying to get this working now for almost 7
>> weeks.
>>
>> The bug has been fixed but not upstreamed into main yet.
>>
>> On 28 March 2013 20:40, Michael T. Dean <mtdean at thirdcontact.com> wrote:
>>> On 03/28/2013 03:51 PM, Another Sillyname wrote:
>>>> As the device isn't supported properly in Myth/Linux I had to compile
>>>> the V4L drivers, I'm running Fedora 18 x64 Kernel 3.8.4-202 and V4L
>>>> compiled last night, using Mythtv from the RPMFusion repos so
>>>> 26.0.7--18.
>>>
>>> What?  According to:
>>>
>>> http://www.linuxtv.org/wiki/index.php/DVB-T_USB_Devices
>>>
>>> the Hauppauge Nova-TD Stick is supported in Linux and has been since
>> kernel
>>> version 2.6.24 (which is pretty ancient), and MythTV has had support for
>> the
>>> Linux DVB API for ages.
>>>
>>> You're not trying to set it up as a V4L device in MythTV are you?
>>>
>>> Mike
>>>
>>> _______________________________________________
>>> mythtv-dev mailing list
>>> mythtv-dev at mythtv.org
>>> http://www.mythtv.org/mailman/listinfo/mythtv-dev
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