On Thu, 2008-11-20 at 12:39 +0200, Dmitry Podyachev wrote:
> Dear Andy,
> Is any news about changes for cx18 ?

Dmitry,

For your analog front-end problem - No not yet.  I haven't had time.  I
suspect the problem is because of false horizontal sync's being declared
because the AGC is up too high when the bright signal comes in.

1. The strategy may be to check the AGC level after the AGC settles
after tuning to a channel or switching to a baseband input.  If the
level is up near the top of the AGC's range, maybe +9 dB out of the +12
dB max (0x36 or 0x37 in register 0x488) then turn on the +12 dB
amplifier for the input to get more dynamic range out of the final stage
of the amplifier.

2. Maybe you could also, after changing the channel and letting the AGC
settle, record the AGC value for that channel or input and then put the
AGC in a manual mode.

3. There are also some registers about what levels are needed for when
sync is declared that can be adjusted.
 

4. Probably the easiest thing to do first though, is to make sure you
have a clean, reasonably strong signal:

http://www.ivtvdriver.org/index.php/Howto:Improve_signal_quality

before going through all that other trouble.



> May be I can help himself ?
> have a nice day

Regards,
Andy

> with best regards, Dmitry
> 


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