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Hi, Am 14.08.2012 22:15, schrieb Reinhard Nissl:
Hi, Am 14.08.2012 14:05, schrieb Manu Abraham:My other device, a STB0899, always reports the set frequency. So it seems driver dependent whether it reports the actually locked frequency found by the zig-zag-algorithm or just the set frequency to tune to.The STV0299 blindly sets the value based on a software zigzag (due to simpler hardware), but this might not be accurate enough. On the other hand, the STB0899 internally does zig-zag in hardware for DVB-S2, and partly in software for DVB-S. In any event, the get_frontend callback should return the value that is read from the demodulator registers, rather than the cached original value that which was requested to be tuned. The stb0899 returns only the cached value IIRC. Maybe I will fix this soon, or maybe you can send a patch.See the attached patch. This is what I get after the patch: Sat. Pol. Band Freq (MHz) Set Freq (MHz) Get Delta (MHz) S19,2E H L 10744 10748,474 4,474 S19,2E H L 10773 10777,944 4,944 S19,2E H L 10832 10836,953 4,953 S19,2E H L 10861 10868,774 7,774 S19,2E H L 10920 10924,312 4,312 S19,2E H L 11023 11026,827 3,827 S19,2E H L 11170 11175,423 5,423 S19,2E H L 11243 11248,452 5,452 S19,2E H L 11302 11307,371 5,371 S19,2E H L 11361 11366,427 5,427 S19,2E H L 11420 11425,473 5,473 S19,2E H L 11464 11468,876 4,876 S19,2E H L 11493 11498,421 5,421 S19,2E H L 11523 11529,080 6,080 S19,2E H L 11582 11586,942 4,942 S19,2E H L 11611 11618,785 7,785 S19,2E H L 11641 11645,951 4,951 S19,2E H L 11670 11675,450 5,450 S19,2E H H 11719 11724,970 5,970 S19,2E H H 11758 11763,975 5,975 S19,2E H H 11797 11802,978 5,978 S19,2E H H 11836 11841,972 5,972 S19,2E H H 11875 11880,951 5,951 I'll have to let VDR "travel" across the transponders several times to see whether I get similar results for the previously mentioned transponder on the stv0299 device.
Please have a look at http://home.vrweb.de/~rnissl/test/tune2.pdfFor the topmost samples (S13.0E, Band H, Pol. V) it seems like there is an average offset of 6.7 MHz. One can see the temperature dependent drift of the LNB between night and day (ambient temperature 12.55 °C vs. 28.35 °C) by the "bars" which are created of co-located samples.
BTW: x-axis enumerates transponders (which VDR could get a lock for) in the corresponding band ordered by increasing frequency. To get all bands in one diagram, each band adds an additional offset of 10 MHz, so simply ignore the ten's digit.
While the S13.0E transponders look good besides a single transponder which shows a wider range of frequency offsets, the S19.2E transponders in the high bands show a similar wide range for several "highest" frequency transponders. I have no idea why this also happens for almost any S19.2E low band vertical transponder.
Can anyone explain that for example by driver or device limitations?I hope the offsets from 4.7 MHz to 6.7 MHz are not an issue of the STB0899 device. If I recall correctly, I had tuning issues also on my 9 year old TechniSat receiver, e. g. Pro7 on S19.2E was working in the morning but not in the evening, and adjusting diseqc settings to compensate for about 5 MHz solved the issue.
Recently I ordered a recent TechniSat receiver and it tunes awfully slow -- I'll now try to tweak diseqc settings and see if things get better ;-)
Bye. -- Dipl.-Inform. (FH) Reinhard Nissl mailto:rnissl@xxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html