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0% Signal Quality Why?
Posted: Wed Sep 19, 2007 10:42 pm
by redbull86
Hello,
First of all sorry for my bad English.
I have a Pinnacle PCTV 450 USB TV card. This card has 1 year long done well. The last time i have many problems with this card. I can watch many channels but there are many channels which I can’t watch. ProgDVB indicates a Signal level around 80 and 90% and a signal quality of 0%. But when I connect my normal receiver to the same LNB then I can watch this channels and i get a signal quality around the 85 and 90%. Do you have any Idea How to solve this problem?
Posted: Thu Sep 20, 2007 12:19 pm
by redbull86
My message is moved to the category hardware problems. But this is not a hardware problem because i've changed this card 1 week ago. I had 2 year waranty on this card, so this should'nt be a hardware problem. I suggest it is a codec problem. But i don"know what.
Please help...
Posted: Thu Sep 20, 2007 1:48 pm
by Juergen
A codec won't interfere with level and quality readings at all.
So, to go systematically, do you find any stations on scanning?
If not, that's driver, software comaptibility or hardware related.
Does the original application work, that came with your card, or any other?
If not, you can forget about compatibility issues for now...
What does the level display show with no LNB connected? That's supposed to be tuner background noise and / or simply misinterpreting of a driver given scale offset or factor.
Stations you can't watch may be crypted, then that's not to be diesussed here.
But if they aren't even listed after a transponder scan, something else is wrong.
Posted: Thu Sep 20, 2007 2:44 pm
by redbull86
Juergen wrote:A codec won't interfere with level and quality readings at all.
So, to go systematically, do you find any stations on scanning?
If not, that's driver, software comaptibility or hardware related.
Does the original application work, that came with your card, or any other?
If not, you can forget about compatibility issues for now...
What does the level display show with no LNB connected? That's supposed to be tuner background noise and / or simply misinterpreting of a driver given scale offset or factor.
Stations you can't watch may be crypted, then that's not to be diesussed here.
But if they aren't even listed after a transponder scan, something else is wrong.
- When i do a scan it finds manny stations. But not every station. When i connect a normal receiver on the same LNB and i do a scan then it finds all station.
- The transponders of the original application are out of date and i don't know how to update those transponders. That's why i'm using progdvb
- When i disconnect the LNB cable the level display shows around the 50% and i hear tuner background noise
- The stations which i can't watch are not crypted
Posted: Fri Sep 21, 2007 5:34 am
by Juergen
Transponders normally are listed inside of INI files, that are named after the position angle, in east nomenclature and multiplied by ten.
F.e., 19.2°E Astra needs a transponder file named 0192.ini.
These are formatted text files, can be handled with editor / notepad.
However, on a transponder with nice level but no quality, try to manually detune the transponder frequency up to 5 MHz up and down. If that helps to get locked, correct the LOF in use for the same amount to the opposite direction.
Posted: Fri Sep 21, 2007 1:57 pm
by redbull86
The original application is Pinnacle TVCenter Pro. I looked for theese files but there ar no ini files. I think it is build in the application.
Where and how can i changes the LOF settings in ProgDVB?
P.S. sometimes when a station has 100% signal quality and i close ProgDVB and start it again then the same station has 0% signal quality. When i click two, three times on this station sometimes it works and sometimes it won't work.
Posted: Fri Sep 21, 2007 2:22 pm
by redbull86
Thanks a lot!!!
It worked i did +1 for every stations frequency. But this is takes a lot time. If you can tell me what i now should change on the LOF settings i will be very happy
The current LOF settings are:
LOF 1: 9750 Mhz
Switch: 11700
LOF 2: 10600
thanks again...
Posted: Fri Sep 21, 2007 2:41 pm
by Juergen
If you need +1 MHz in manual transponder scan, you should not store this but correct the LOF (that's used for that transponder) by -1 MHz.
That's quick and easy, and it won't touch anything else but the original source of that problem, a tiny LOF adjusting tolerance offset of that LNB (band).
Compensating an offset means to correct to the opposite direction, due to the tuner frequency calculation method for Ku band satellite use.
The tuner itself can tune from 950 MHz to 2150 MHz, the IF range, that's coming from the LNB.
There are three independent numbers a DVB tuner needs to calculate it's internal stages for tuning to a station:
- the LOF in use (that must suit the physical one of the LNB)
- the transponder frequency from the transponder ini file for scanning
- the channel database entries for zapping
The LOF value interacts with one of the others, depending on what mode you're in.
Posted: Sat Sep 22, 2007 2:56 pm
by redbull86
Is this the screen where i can modify LOF settings?
I have changed the LOF value to 9749 is this correct?
Then i did a autoscan and it has found many station.
There are still some stations which are not working correct. For example when i click on one of this stations it works correct and when i switch to another station then it is still working but when i switch back to the other station the signal quality meter shows now 0%. When i click sometimes on this station sometimes it works but not every time. This happens with some stations not every station has this problem. Any idea how to fix this?
Posted: Sat Sep 22, 2007 8:31 pm
by Juergen
That's the correct place to correct a deviating LNBs LOF.
To find out the amount of an offset, go 'search transponder', on one with that problem and find the limits of the hold range, by stepping up and down in 1 MHz intervals, up to around +/- 5 MHz.. The centre of the hold range gives the offset to use.
Don't store there, use LNB settings instead.
Posted: Sun Sep 23, 2007 12:34 pm
by redbull86
Juergen wrote:That's the correct place to correct a deviating LNBs LOF.
To find out the amount of an offset, go 'search transponder', on one with that problem and find the limits of the hold range, by stepping up and down in 1 MHz intervals, up to around +/- 5 MHz.. The centre of the hold range gives the offset to use.
Don't store there, use LNB settings instead.
Ok...
Posted: Mon Sep 24, 2007 4:42 pm
by redbull86
I have changed the LOF Settings as follow:
LOF 1: 9749 MHZ
Switch: 11800 MHZ
LOF 2: 10599 MHZ
With this settings some stations are working. But The other stations which were working with the old settings LOF 1: 9749, Switch: 11700, LOF 2: 10599 are now not working.
So what i understand is that some stations need a Switch value of 11700 MHZ and other stations need a Switch value of 11800 MHZ. what can i do now?
Posted: Mon Sep 24, 2007 5:47 pm
by Juergen
As both of your LOFs are set 1 MHz lower than default, all transponders would be tuned this waym regardless of switch settings.
The only difference then would be, the switch decides to either use low of high band for the transponders within the possible range of 11550 to 11900 MHz.
Close to the band limits, some transponders may come in a little weaker, specially to the upper end of the (low) band, due to cable losses...
That's why in most cases it's best to set to almost the center of the overlapping range from 11550 to 11900.
However, normally a LOF offset is not identical for both bands, check that seperately.
Posted: Tue Sep 25, 2007 11:47 am
by redbull86
I have tried many combination Sometimes it works. But the next day when i start ProgDVB the same problem occurs again. So what is your advice? what should i do?
P.S. Most of the stations work all the time. Only some stations have this problem....
Posted: Tue Sep 25, 2007 7:35 pm
by Juergen
Let's not talk stations, better stay with transponders.
You may provide some examples for those not working ones.
BTW, I don't have 15°W = 345°E here.
And there's no must, the LNB deviation would be 1 MHZ, perhaps try 2 MHz instead.
Another bad chance, your LNB might be temperature sensitive as well.
To minimize thermal drift, let the LNB warm up for half an hour on a horizontal station before looking for offsets.
But don't do this at noon these days, as the thermal radiation of the sun may also interfere, as it has almost the same elevation (exactly at equinoctum).
And keep in mind, an LNB has two independent local oscillators, that may have different calibration errors and thermal drift.
We're talking on ~ +/- 100 ppm = 0.01 % precision, in a weather exposed area that's pretty close to the limits of technology...
Anyway, an LNB may even fail, like partly losing it's thermal stability. This happens quite often, if the casing breaks and dirt or water gets in.