[linux-dvb] Preliminary support of Hauppauge Nova-T 500 Dual (take 2)

Jose Alberto Reguero jareguero at telefonica.net
Wed Sep 20 15:08:59 CEST 2006


El Miércoles, 20 de Septiembre de 2006 11:55, Patrick Boettcher escribió:
> Hi,
>
> On Wed, 20 Sep 2006, Jose Alberto Reguero wrote:
> > I made a experiment, and take the agc params from
> > dib3000p_mt2060_agc_config from  dibusb-common.c line 170 and put in
> > bristol_dib3000p_mt2060_agc_config from dib0700_devices.c line 26 except
> > ".setup" and I have much beter results. I can tune to this frquency with
> > LNA off and with LNA on with good results (similar ber, a little better
> > with LNA on).
>
> Uh la la. Never ever do that. AGC settings are (most of the time)
> determined by a process of calibration (checking for sensitivity, high
> power, backoff in different adjacent channel scenarios (Nordig, MBRAI)).
> The settings which are there are optimized for the nova-t 500 (knowing
> that there is an LNA).
>
> If you now use different settings, they may work very good for you, but
> most likely very bad for others (with other reception conditions). The AGC
> calibration is always a compromise to achieve usable reception for
> everyone.
>
> That reception is working with LNA on and off is, btw, no indicator. The
> LNA should be used, if you live in an area, where signal are very low.
> That the Nova-T 500 has only one LNA for both channels is a bit unlucky,
> that's why it is now switchable with a module parameter.
>
> So once again: unless one is not 100% sure of what he/she is doing, DO NOT
> TOUCH AGC parameters. Otherwise it will be quite impossible to support
> people reporting bad reception quality.
>
> best regards,
> Patrick.
>

I try this because I still have problems with some frecuencys with LNA off 
with your params. Other frecuencys are ok. Maybe there is something wrong in 
the AGC params?

Thanks.
Jose Alberto



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