Hi Andy
> 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.
We can make fake FM1216ME_MK3 compatible tuner for clones. And move clones to it.
After testing each clone with real compatibility with FM1216ME_MK3 we can move to real tuner.
> > > > 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.
Ok. I'll discuss about it with our system programmer.
> > 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.
Yes, you are right. This solutions used for hybrid tuners too.
> > > 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.
>
> >
>
>
> Regards,
> Andy
With my best regards, Dmitry.
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