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Re: [PATCH] FM1216ME_MK3 some changes




Hi,

Am Donnerstag, den 23.04.2009, 21:43 -0400 schrieb Andy Walls:
> Hi Dmitri,
> 
> Thank you for you responses.
> 
> Just a few more comments...
> 
> On Thu, 2009-04-23 at 20:36 +1000, Dmitri Belimov wrote:
> > Hi Andy
> > 
> > > Dmitri,
> > > 
> > > 
> > > On Wed, 2009-04-22 at 17:48 +1000, Dmitri Belimov wrote:
> > > > Hi All
> > > > 
> > > > 1. Change middle band. In the end of the middle band the
> > > > sensitivity of receiver not good. If we switch to higher band,
> > > > sensitivity more better. Hardware trick.
> > > 
> 
> > Several years a go your customers write some messages about bad quality of TV
> > if frequency of TV is the end of band. It can be low band or middle. Our
> > hardware engeneer make some tests with hardware TV generator and our TV tuners.
> > 
> > If we set default frequency range for low and middle band, quality of TV signal 
> > on 159MHz and 442 MHz is bad. When we make our changes with moving end of bands
> > the quality of TV much better. And our system programmer for OS Windows use changed
> > bands for drivers. Customers be happy.
> 
> OK.  A properly run experiment wins over theory every time. :)
> 
> 
> 
> > You can test it if in your placement available TV programm on 159MHz or 442MHz. This trick
> > can be usefull for other tuners.
> 
> If you look at tveeprom.c, a number of other tuners are using that tuner
> definition:
> 
> $ grep FM1216ME_MK3 tveeprom.c
> 	{ TUNER_PHILIPS_FM1216ME_MK3, 	"Philips FQ1216ME MK3"},
> 	{ TUNER_PHILIPS_FM1216ME_MK3, 	"Philips FM1216 ME MK3"},
> 	{ TUNER_PHILIPS_FM1216ME_MK3, 	"LG S001D MK3"},
> 	{ TUNER_PHILIPS_FM1216ME_MK3, 	"LG S701D MK3"},
> 	{ TUNER_PHILIPS_FM1216ME_MK3, 	"Philips FQ1216LME MK3"},
> 	{ TUNER_PHILIPS_FM1216ME_MK3, 	"TCL MFPE05 2"},
> 	{ TUNER_PHILIPS_FM1216ME_MK3, 	"TCL MPE05-2"},
> 	{ TUNER_PHILIPS_FM1216ME_MK3, 	"Philips FM1216ME MK5"},
> 
> If your change makes things bad for the other tuners, we'll probably
> have to create an alternate entry for the other tuners instead of using
> the FM1216ME_MK3 defintion.  I suspect most of them are clones of the
> FM1216ME MK3 however, so it probably won't matter.
> 
> > > > 3. Set charge pump bit
> > > 
> > > This will improve the time to initially tune to a frequency, but will
> > > likely add some noise as the PLL continues to maintain lock on the
> > > signal.  If there is no way to turn off the CP after the lock bit is
> > > set in the tuner, it's probably better to leave it off for lower
> > > noise and just live with slower tuning.
> > 
> > We discuss with our windows system programmer about it. He sad that
> > in analog TV mode noise from PLL don't give any problem.
> 
> I would be concerned about phase noise affecting the colors or any FM
> sound carriers.  If the noise isn't noticably affecting colors to the
> human eye (do color bars look OK?), or sound to the human ear, then OK.
> 
> 
> >  But in digital TV mode
> > noise from PLL decreased BER.
> 
> I thought the FM1216ME MK3 was an analog only tuner.  I guess I don't
> know DVB-T or cable in Europe well enough.

that is for sure, analog only. 

Dmitry is preparing something for the MK5 too and the FMD1216ME/I MK3
hybrid. Hmm, I wonder if Hans and Jarod do have something to improve for
the MK4 too and the others.

As said, I don't care for changes within the freq. gap and accept
everything working better there ;)

> 
> > > Leaving the CP bit set should be especially noticable ad FM noise when
> > > set to tune to FM radio stations.  From the FM1236ME_MK3 datasheet:
> > > "It is recommended to set CP=0 in the FM mode at all times."
> > > But the VHF low band control byte is also used when setting FM radio
> > > (AFAICT with a quick look at the code.)
> > 
> > Yes. You are right. We can swith CP off in FM mode.
> 
> OK.  Thank you.
> 
> > With my best regards, Dmitry.
> 
> 
> Regards,
> Andy
> 

Cheers,
Hermann


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