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ASUSTeK Tiger LNA Hybrid Capture Device - signal unstable.

Hi,

Ra.M. schrieb:
> Hartmut Hackmann wrote:
>> Hm, the LNA has such a high gain... i dont think that a additional
>>  amplifier
>> will give improvement. Please do the following: set the options debug=1
>>  for
>> the modules tuner and tda827x. and send me the kernel log of driver load
>> and tuning attempts.
>> The card i had in hands had no sensitivity problems. But is was a
>>  'early
>> sample' You might decide to play with the antenna switch config
>>  entry
>> in saa7134-dvb.c.
>>
>> Hartmut
>>
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>>   
> 
> 
> I have enabled debug=1 for modules tuner and tda827x; this is the
> kernel log:
> 
> ----------------------- driver load ------------------------
> 
> Mar 17 02:28:34 darkstar kernel: tuner 2-004b: chip at addr 4b is a tda8290
> Mar 17 02:28:34 darkstar kernel: tuner 2-004b: Setting mode_mask to 0x0e
> Mar 17 02:28:34 darkstar kernel: tuner 2-004b: Calling set_type_addr for
> type=54, addr=0xff, mode=0x04, config=0x02
> Mar 17 02:28:34 darkstar kernel: tuner 2-004b: set addr for type -1
> Mar 17 02:28:34 darkstar kernel: tuner 2-004b: defining GPIO callback
> Mar 17 02:28:34 darkstar kernel: tuner 2-004b: saa7133[0] tuner I2C addr
> 0x96 with type 54 used for 0x0e
> Mar 17 02:28:34 darkstar kernel: tuner 2-004b: defining GPIO callback
> Mar 17 02:28:34 darkstar kernel: tuner 2-004b: saa7133[0] tuner I2C addr
> 0x96 with type 54 used for 0x0e
> Mar 17 02:28:34 darkstar kernel: tda827x: tda827x_attach:
> Mar 17 02:28:34 darkstar kernel: tda827x: tda827xa tuner found
> Mar 17 02:29:09 darkstar kernel: tuner 2-004b: Cmd VIDIOC_S_STD accepted
> for analog TV
> Mar 17 02:29:09 darkstar kernel: tuner 2-004b: switching to v4l2
> Mar 17 02:29:09 darkstar kernel: tuner 2-004b: tv freq set to 400.00
> Mar 17 02:29:09 darkstar kernel: tuner 2-004b: setting tda8290 to system B
> Mar 17 02:29:09 darkstar kernel: tuner 2-004b: tda827xa config is 0x02
> Mar 17 02:29:09 darkstar kernel: tuner 2-004b: setting LNA to high gain
> Mar 17 02:29:09 darkstar kernel: tuner 2-004b: AGC2 gain is: 0
> Mar 17 02:29:09 darkstar kernel: tuner 2-004b: setting LNA to low gain
> Mar 17 02:29:09 darkstar kernel: tuner 2-004b: tda8290 not locked, no
> signal?
> Mar 17 02:29:09 darkstar last message repeated 2 times
> Mar 17 02:29:09 darkstar kernel: tuner 2-004b: adjust gain, step 1. Agc:
> 75, ADC stat: 0, lock: 0
> Mar 17 02:29:10 darkstar kernel: tuner 2-004b: adjust gain, step 2. Agc:
> 231, lock: 0
> Mar 17 02:29:10 darkstar kernel: tuner 2-004b: adjust gain, step 3. Agc: 75
> Mar 17 02:29:10 darkstar kernel: tuner 2-004b: Cmd TUNER_SET_STANDBY
> accepted for analog TV
> 
> ------------------------- tuning attempts ---------------------------
> 
> Mar 17 02:30:40 darkstar kernel: tda827x: tda8275a AGC2 gain is: 0
> Mar 17 02:31:11 darkstar last message repeated 3 times
> Mar 17 02:32:13 darkstar last message repeated 12 times
> Mar 17 02:32:51 darkstar last message repeated 10 times
> Mar 17 02:34:32 darkstar last message repeated 14 times
> Mar 17 02:34:39 darkstar last message repeated 2 times
> Mar 17 02:37:13 darkstar kernel: tda827x: tda8275a AGC2 gain is: 0
> Mar 17 02:38:16 darkstar last message repeated 10 times
> 
> 
> Last night, for about 5 minutes, some channels have become perfectly
> stable;
> probably, signal fluctuation?
> 
Maybe, but see below.
I just noticed that one of the changes i made is not good. It depends
on the module load order whether it works or not. On your board, it is
important that the "analog tuner" is in standby mode when dvb-t is running.
In your case, it seems to have worked but i am not sure. So if in doubt,
please try to load an analog tv application before using DVB-T until i
found a better solution.
The other point: there is a high signal amplitude at the antenna input.
But due to its principle, the tuner "sees" strong transmitters on other
frequencies. Do you have a strong transmitter nearby? Is your antenna
cable properly shielded?
When you try to tune to a station, what does tzap tell you?


Hartmut

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