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Electrode 05-12-2010 09:13 PM

Problems with DVB-S and a dual-band LNB
 
I just got my hands on a Hauppauge WinTV-Nova-HD-S2 satellite receiver card, and it seems to be working. I have been able to find signals from satellites, and even watch some of them.

I use a 10 foot dish with a dual-band feed - standard C-band and Universal Ku-band with a DiSEqC switch between them.

C-band works perfect:
Code:

electrode@belphegor:~$ dvbstream -c 1 -D 1 -f 1150000 -s 28111 -p H -o:test.ts 8192
dvbstream v0.7 - (C) Dave Chapman 2001-2004
(snip)
DISEQC SETTING SUCCEDED
Getting frontend status
Bit error rate: 0
Signal strength: 56000
SNR: 30311
UNC: 0
FE_STATUS: FE_HAS_SIGNAL FE_HAS_LOCK FE_HAS_CARRIER FE_HAS_VITERBI FE_HAS_SYNC

MAP 0, file test.ts: From -1 secs, To -1 secs, 2 PIDs -  0 8192
dvbstream will stop after -1 seconds (71582788 minutes)
Streaming 1 stream
Program n. 101, name: 'HQ1'
Program n. 102, name: 'HQ2'
Program n. 103, name: 'HQ3'
Program n. 104, name: 'HQ5'
Program n. 105, name: 'HQ5'

I can pipe that to mplayer and watch some TV - or run dvbscan to build a channels.conf and use szap. The problem arises when I try Ku-band.

Code:

electrode@belphegor:~$ dvbtune -c 1 -D 2 -f 12152000 -s 20000 -p H 
Using DVB card "Conexant CX24116/CX24118"
tuning DVB-S to L-Band:0, Pol:H Srate=20000000, 22kHz=off
polling....
Getting frontend event
FE_STATUS:
polling....
Getting frontend event
FE_STATUS: FE_HAS_SIGNAL FE_HAS_LOCK FE_HAS_CARRIER FE_HAS_VITERBI FE_HAS_SYNC
Event:  Frequency: 12152000
        SymbolRate: 20000000
        FEC_inner:  9

Bit error rate: 0
Signal strength: 51392
SNR: 38092
FE_STATUS: FE_HAS_SIGNAL FE_HAS_LOCK FE_HAS_CARRIER FE_HAS_VITERBI FE_HAS_SYNC

electrode@belphegor:~$ dvbstream -c 1 -D 2 -f 12152000 -s 20000 -p H -o:test.ts 8192
dvbstream v0.7 - (C) Dave Chapman 2001-2004
Released under the GPL.
Latest version available from http://www.linuxstb.org/
Adding whole transport stream to map n. 0
Open file test.ts
Tuning to 12152000 Hz
Using DVB card "Conexant CX24116/CX24118", freq=12152000
tuning DVB-S to Freq: 1552000, Pol:H Srate=20000000, 22kHz tone=off, LNB: 2, SLOF 11700, LOF1: 9750, LOF2: 10600
DISEQC SETTING SUCCEDED
Getting frontend status
Not able to lock to the signal on the given frequency

MAP 0, file test.ts: From -1 secs, To -1 secs, 2 PIDs -  0 8192
dvbstream will stop after -1 seconds (71582788 minutes)
Streaming 1 stream

As you can see there, I am able to tune in a transponder using dvbtune, but when I try dvbstream it is unable to locate the signal. I can run dvbscan -c while dvbtune is running and it will successfully map the stream, but szap fails to tune in the signal.

Can anyone offer some advice as to what's going on, and how to fix this? I have confirmed with an external meter that the 22 kHz tone to switch the Ku LNB to the US band is on, so that's not the problem.

Edit: it looks like, whatever the problem is, it occurs right when the tools start.

I tried running the coax to my STB and hooking the tuner card up to the STB's passthrough jack, then setting up the LNB using the STB. When the STB is on, it will pass signal from the LNB to the passthrough jack, but will block any voltage or commands coming from the slave receiver. When it's off, voltages and commands are allowed to pass from the slave to the LNB.

If I set things up with the STB, dvbstream and szap work just fine on Ku-band downlinks. If I shut the STB off while receiving (which hands control over to the tuner card), the signal stays locked and I can keep watching it until I stop the tuner app. If I subsequently try to watch another Ku-band downlink, it will not work until I set the LNB up with the STB again. dvbtune still works on Ku with the STB off, and C-band is unaffected by all this.

Edit #2: Solved, sorta. I've gotten dvbstream to work on Ku:
Code:

dvbtune -c 1 -D 2 -f 12152000 -s 20000 -p H && dvbstream -c 1 -f 12152000 -s 20000 -p H -o 8192 | mplayer -tsprog 462 -
szap still doesn't work, but I will mess with that some more later on.

brucehinrichs 05-19-2010 01:12 PM

Since it's marked solved, I'll take it off of the zero reply list. :)


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