Page 1 of 1
Channel scan problem in Windows Vista 64Bit
Posted: Wed Nov 21, 2007 1:54 pm
by redbull86
Hello,
When i try to scan for channels in Windows Vista 64Bit ProgDVB doesn"t find any channel. When i click on Lock it shows a Signal Level of around 90% and a Signal Quality of 100% but when i click on scan on the same transponder it doesn"t find any channel. This happens only with channels with a low symbolrate. Channesl with a high symbolrate like 15555, 22500 or 24444 MHZ don't have this. When i click on the scan button then the channels are shown.
My configuration:
Windows Vista 64Bit operating system
Pinnacle PCTV 450e SAT USB (driver version 1.0.2.4)
ProgDVB 5.12
Posted: Wed Nov 21, 2007 2:10 pm
by Juergen
Perhaps your LNB's LOF(s) do have a small offset, as tuning small bandwidth signals requires more precision.
Try to tune up and down manually in steps of 1 MHz, to a maximum offset of +/- 5MHz.
Don't store anything.
If finding a lock, locate the center of the hold range for it.
If by this getting an idea about a systematical deviation, correct the LOF value for that amount, into the opposite direction.
Then rescan and store.
No idea, if your tuner has any general limitations, regarding low data rates. These days, this should not be, normally.
Posted: Wed Nov 21, 2007 4:31 pm
by redbull86
Juergen wrote:Perhaps your LNB's LOF(s) do have a small offset, as tuning small bandwidth signals requires more precision.
Try to tune up and down manually in steps of 1 MHz, to a maximum offset of +/- 5MHz.
Don't store anything.
If finding a lock, locate the center of the hold range for it.
If by this getting an idea about a systematical deviation, correct the LOF value for that amount, into the opposite direction.
Then rescan and store.
No idea, if your tuner has any general limitations, regarding low data rates. These days, this should not be, normally.
But it shows 100% signal quality when i click the lock button so it should find channels when i click the scan button
when i do + or - 1 mhz now the meter shows 0% when i click the lock button
and with the same frequency's it works in Windows XP
Posted: Wed Nov 21, 2007 8:09 pm
by Juergen
Sorry, did not recognize at once, you are talking about cable TV.
So this should read
"155.55, 225.00 or 244.44 MHz"
instead of
"15555, 22500 or 24444 MHZ"
On cable, there's no such thing an an LOF.
As I don't have cable over here, no way to proceed.
Anyone else, perhaps?
Posted: Wed Nov 21, 2007 8:20 pm
by redbull86
Juergen wrote:Sorry, did not recognize at once, you are talking about cable TV.
So this should read
"155.55, 225.00 or 244.44 MHz"
instead of
"15555, 22500 or 24444 MHZ"
On cable, there's no such thing an an LOF.
As I don't have cable over here, no way to proceed.
Anyone else, perhaps?
no no i'm not talking about Cable TV

i"m talking about Satelite TV (DVB-S)
Posted: Wed Nov 21, 2007 9:21 pm
by Juergen
So it should have been ksps (kilo symbols per second).
To be able to help in any way, it's essential, to know what we are talking about, exactly.
I won't call 15555 ksps a low data rate, it should be working fine on all equipment. Just a precise LOF is mandatory, as usual.
Now, partly depending on the hardware, the tuning frequencies are controlled by some AFC (automatic frequency control) / AFT (automatic fine tuning) logics.
Normally, they also have a locked / unlocked state, that's being talked to the software, and temporarily being set to neutral on any manual tuning attempts.
That's why I pointed towards finding a lock range and it's centre, if possibly being off center.
Under normal conditions, DVB-S transponders result i9n a hold range of +/- a few MHz, e.g. 12188 sohould work between around 12184 and 12192, before losing lock.
Else something differrent would be wrong, like data rate (which must be very precise), or general driver trouble, or whatever else.
Posted: Thu Nov 22, 2007 10:19 am
by redbull86
Juergen wrote:So it should have been ksps (kilo symbols per second).
To be able to help in any way, it's essential, to know what we are talking about, exactly.
I won't call 15555 ksps a low data rate, it should be working fine on all equipment. Just a precise LOF is mandatory, as usual.
yes you"re right it"s ksps

channels with a symbolrate 15555 and above are working fine.
And channels with a symbolrate lower as 15555 can be locked then the meter shows a signal quality of 100% but when i click scan now on that transponder ProgDVB doesn"t find any channel
Posted: Thu Nov 22, 2007 11:25 am
by Juergen
From my point of view, this must be hardware / driver related somehow.
With my hardware, I don't have any trouble, tuning into carriers with data rates of above ~ 1000 ksps (~ 1600 really tested over here).
My former model, SS1 rev. 1.3, had a minimum data rate of around 8000 ksps, with some fixes it could work up from 4000.
Level readings on SCPC are not very reliable, they tend towards displaying to high, and they may even be irritated by neighbour signals on split transponders a bit.