[linux-dvb] SkyStar HD2 issues, signal sensitivity, etc.

David Lister foceni at gmail.com
Mon Apr 20 22:46:08 CEST 2009


Hello all,

I took my time with this reply to gather verified data and information.
I wanted to be sure of my facts and have pristine HW for testing (you
mentioned the possibility of broken/fake HW).

1) My cards are 100% genuine - confirmed by Twinhan.
2) I had one of the cards replaced for tests using new mantis-v4l S2API
3) Testing was conducted using mantis-v4l exclusively, with a single
card and with both cards connected (same results).

Manu Abraham wrote:
> Manu Abraham wrote:
>> Dave Lister wrote:
>>>> On Sat, Apr 11, 2009 at 5:47 AM, Dave Lister <foceni at gmail.com> wrote:
>>>>> RESULTS (using "s2" dvb-apps):
>>>>> - scanning DVB-S works
>>>>> - scanning DVB-S2 doesn't work
>>>>> - zapping DVB-S is fast
>>>>>
>>> For other SkyStar HD2 users, this is a summary as of 2009.04.14:
>>>   - kernel 2.6.29 + mantis-v4l works (except DiSEqC as far as I can tell)
>>
>> Diseqc works fine over here, with the VP-1041 and other cards, using
>> the mantis-v4l tree.

You were right, DiSEqC is working. The reason was forgotten loop through
my STB. Once removed from the cable, DiSEqC started working.

>> The s2-liplianin tree doesn't use an updated tree for the mantis
>> based devices unfortunately. It is stuck with older changesets of
>> the mantis tree.

Driver mantis-v4l suffers from the same issues as s2-liplianin (see the
next paragraph).

>>> Common issues:
>>>   - zapping DVB-S2 channel causes tuner HW lockup (loss of signal until reboot)
>>>   - zap DVB-S2 channel => AWFUL ultra-high pitched noise emitted from
>>> the card (capacitors or coils?) - makes your head hurt in about 30mins
>>>   - very poor TS (picture data) quality; signal = 95%, SNR = 70%,
>>> STB/TV gives superb picture, but SkyStar/PC picture is corrupted every
>>> few seconds, sound glitches, etc. (as if the signal was like 40% on
>>> STB) - confirmed in VDR (Xine), MythTV, mplayer.

- Unusable DVB-S2 is a fact. It locks up the card and prevents further
usage. Some S2 transponders cannot be locked even after reboot, which
means this card is basically just DVB-S. There are MANY better supported
DVB-S and even DVB-S2 cards out there.

- High-pitched noise is NOT present with the new card + mantis-v4l. That
might have been HW or s2-liplianin issue.

- Poor TS quality is a fact. This card doesn't even have freq. shielding
on the board, which might be the reason on its own.

>> * If you had those changes on your hardware and your card was
>> susceptible to such issues, then that could be a possible reason.
>> * There are quite some hardware pirates, as noted here ..

Not possible, I have a new card (verified by Twinhan as genuine), which
has been used with mantis-v4l only and has the same issues.

>> In any of your cases, If you have hardware related issues please
>> contact to your supplier to have it checked/replaced by them.

My problems are not caused by defective or fake HW. This has been
confirmed above all suspicions.

>> NOTE: Always try to stick with a tree that's a mainline tree or the
>> development tree, rather than tree's with unknown changes.

When there are 3-4 different driver trees of various maturity, none of
which is working properly, one has no other alternative than to try
everything. Not to mention that mantis-v4l was first uploaded several
day AFTER I began installations. Back then, s2-liplianin was the only
S2API choice.

My signal is now at 95-99% and SNR reported by the STB is 70%. With
SkyStar I can see these numbers:

# femon -a0
FE: STB0899 Multistandard (DVBS)
Problem retrieving frontend information: Operation not supported
status  CVYL | signal 014c | snr 006b | ber 00000000 | unc 00000000 |
FE_HAS_LOCK
Problem retrieving frontend information: Operation not supported
status  CVYL | signal 014c | snr 006b | ber 00000000 | unc 00000000 |
FE_HAS_LOCK
Problem retrieving frontend information: Operation not supported
status  CVYL | signal 014c | snr 006a | ber 00000000 | unc 00000000 |
FE_HAS_LOCK



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