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From: Antti Palosaari <crope@iki.fi>
To: Rune Evjen <rune.evjen@gmail.com>
Cc: linux-media@vger.kernel.org, Markus Rechberger <mrechberger@gmail.com>
Subject: Re: PCTV nanoStick T2 290e (Sony CXD2820R DVB-T/T2/C) - DVB-C channel scan in mythtv - missing
Date: Tue, 21 Jun 2011 00:02:35 +0300	[thread overview]
Message-ID: <4DFFB56B.3000802@iki.fi> (raw)
In-Reply-To: <BANLkTi=gdVhVKjF4tqUwy+DxFv9imUipHw@mail.gmail.com>

On 06/20/2011 11:55 PM, Rune Evjen wrote:
> 2011/6/20 Markus Rechberger<mrechberger@gmail.com>:
>> to tell the difference the amplifier is for DVB-T2, DVB-C is disabled
>> in windows because it's not reliable.
>> Technically the chip supports it but the LNA decreases the quality.
>> There are already some other PCI boards
>> out there with that chip which do not use that LNA which should have a
>> better performance with that Sony chip.
>
> Is it possible to work around this by disabling the lna or is the
> quality decreased permanently as part of the hardware design,
> independently of whether the lna is enabled or not ?
>
> I searched the linux-media list and it seems that an lna option was
> discussed as a module parameter, but modinfo for the module I use [1]
> (using the media_build git repository) doesn't show a lna parameter.
> Can the lna be disabled in another way ?

LNA is controlled by demod GPIO line. I don't remember if it is on or 
off for DVB-C currently. Look em28xx-dvb.c file, you can disable or 
enable it from there (needs re-compiling driver).

I also saw BER counter running some muxes during development, but I 
think all channels I have are still working. And I didn't even have time 
to optimal parameters for tuner / demod. I will try to examine those 
later...

regards
Antti



-- 
http://palosaari.fi/

  reply	other threads:[~2011-06-20 21:02 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-06-12  8:23 PCTV nanoStick T2 290e (Sony CXD2820R DVB-T/T2/C) - DVB-C channel scan in mythtv - missing Rune Evjen
2011-06-12 11:08 ` Antti Palosaari
2011-06-20 19:29   ` Rune Evjen
2011-06-20 19:55     ` Markus Rechberger
2011-06-20 20:55       ` Rune Evjen
2011-06-20 21:02         ` Antti Palosaari [this message]
2011-06-20 21:10           ` Markus Rechberger
2011-06-20 21:20           ` Rune Evjen
2011-06-20 21:25             ` Antti Palosaari
2011-06-20 21:29               ` Antti Palosaari
2011-06-20 23:00                 ` Rune Evjen
2011-06-20 21:04         ` Markus Rechberger
2011-06-20 21:10           ` Antti Palosaari
2011-06-20 21:17             ` Markus Rechberger

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