Blind scans

[Megatron817]

The blind scans don't always come up with channels when channels are there.
what I have to do is send my scan xml to the computer then add the found new tp's with TS-Satellite editor and go to signal finder and see if I have SNR/AGC on the newly added tp if I have signal I Then press the green button to scan and the channels are found.
It seems to find the tp's great just not the channels all the time.

[el bandido]

Some examples would help. What satellite and what transponders have this problem?
Are you blindscanning for free channels Only?

[Megatron817]

Tonight I was scanning 91w ku. some blind scans was missing some of the regular channels that are usually there like news one feeds and other channels it would find. not really any one transponder just seems to randomly miss the channels because when I look at the scan xml it seen or found the transponder just did not scan any channels on that transponder. But if I try to blind scan again the channels it missed the first time would be found. some blind scans seem to be perfect where others would not be. I have tried it both ways free channels or all and it will miss channels some times, other times not.

[Megatron817]

Blind scanning with DiSEqC switch.
Took swich out of line and did 3 back to back blind scans of 91w Ku. all 3 scans were good found transponders along with the channels.
Put a different brand switch back on "Pansat" going to see how it works out.

[Megatron817]

The different diseqc has been working great with the blind scan plugin.
If I knew it was that I would have never started this thead but if anyone else has this problem maybe this thread will help.
Also wanted to say thanks to those on this forum for all the great information in old post, been reading and learning alot.
Today I got a hauppauge 950q that I ordered preowned off of ebay for under $20
Got It set up very easy from reading this forum.
Thanks!

[el bandido]

There are some problems in the blindscan that should be fixed. But I agree that it does work pretty good as is. I will try to post some examples of blindscan problems later today or tomorrow.

[el bandido]

It does not happen often, but I have noticed that the Zero 4K will log a transponder, then delete it. I am familiar with the enigma2 blindscan plugin, and the enigma2 Service scan python files. I modified the blindscan plugin to print the transponders it finds to the telnet screen. I did not find any good transponders being deleted in the blindscan, so I modified the service scan files to print the transponders to be scanned in the telnet screen, plus count the transponders it scans. The Service scan is receiving the same number of transponders that are found in blindscan, so no transponders are being lost in the blindscan or in the Service scan.

Where are the transponders being deleted???
I dunno.
There are parts of enigma2 that I cannot see, and then there is the blindscan binary file that is located in usr/bin. The blindscan binary file is closed source and is controlled by Vu+. I suspect that there is a duplicate routine being ran in this blindscan binary that is deleting transponders that are possible duplicates. This is the only explanation that makes sense to me as I have never seen this problem in enigma2 before. The transponder that is being deleted at 101W C band is usually Heroes or Decades. These transponders are 3-4 MHZ apart, and they have about the same symbol rate. Other transponders that are being deleted appear to have a similar pattern.

Getting the Service scan to show the total number of transponders that is supposed to be scanned, then comparing that number to how many transponders are actually scanned shows how many transponders are being missed. An example is in the screencaps.

14982

14983

[Megatron817]

Another problem is the start frequency in the blind scan .xml shows 11550 even though 11700 was entered as the start frequency. The stop frequency works fine I enter 12200 instead of 12750. I Use a standard lnb with a range of 11700 -12200 . That would speed blind scans up a bit I would think to get the start frequency correct.

[el bandido]

You have to understand what is going on. Circular or 10750 lnb l.o. blindscan in enigma2 with Vu+ is a hack, similar to the 5150 C band l.o.

Enigma2 only knows one type of lnb for blindscan, which is universal, 9750-10600 l.o. frequencies. To make the Circular or 10750 l.o. work, you have to start it 150 MHz lower. If this is not done, then the first 150 MHz of the blindscan will be missed when using a 10750 lnb. The receiver is not actually scanning 11550 MHZ because the 10750 lnb is not capable of going that low.

[el bandido]

Here is part of the blindscan plugin where the lnb frequencies are corrected.

def correctBugsCausedByDriver(self, tplist) :
if self.is_c_band_scan: # for some reason a c-band scan (with a Vu+) returns the transponder frequencies in Ku band format so they have to be converted back to c-band numbers before the subsequent service search
x = 0
for transponders in tplist:
if tplist[x].frequency > (4200*1000) :
tplist[x].frequency = (5150*1000) - (tplist[x].frequency - (9750*1000))
x += 1

elif self.is_circular_band_scan: # Add Standard 10750 L.O. LNB
x = 0
for transponders in tplist:
tplist[x].frequency = (150*1000) + tplist[x].frequency
x += 1

[Megatron817]

edit

[Megatron817]

I use user defined lnd settings
Lolo 10750
Lohi 10750
Threshold 11700 or 12200 makes no difference.
polarization
tone off

[el bandido]

Use what you want, but the blindscan plugin is coded for Circualr to be used with a 10750 L.O. lnb. That is why your threshold settings makes no difference in a blindscan. The thresholds that are in the plugin overrides it.

Default star/stop frequencies can be set to whatever you want in the blindscan plugin. My defaults are set to 11700 and 12225 as seen here:

self.scan_sat = ConfigSubsection()
self.scan_networkScan = ConfigYesNo(default = False)
self.blindscan_circular_band_start_frequency = ConfigInteger(default = 11700, limits = (11700, 12749))
self.blindscan_circular_band_stop_frequency = ConfigInteger(default = 12225, limits = (11701, 12750))
self.blindscan_C_band_stop_frequency = ConfigInteger(default = 4200, limits = (3001, 4200))
self.blindscan_stop_symbol = ConfigInteger(default = 45, limits = (1, 65))

I added some extra lines so my defaults automatically change for satellites over the Atlantic.

if orb < 2990:
self.blindscan_Ku_band_start_frequency = ConfigInteger(default = 11700, limits = (10700, 12749))
self.blindscan_Ku_band_stop_frequency = ConfigInteger(default = 12250, limits = (10701, 12750))
self.blindscan_C_band_start_frequency = ConfigInteger(default = 3700, limits = (3000, 4199))
if orb >= 2989:
self.blindscan_Ku_band_start_frequency = ConfigInteger(default = 10700, limits = (10700, 12749))
self.blindscan_Ku_band_stop_frequency = ConfigInteger(default = 12750, limits = (10701, 12750))
self.blindscan_C_band_start_frequency = ConfigInteger(default = 3400, limits = (3000, 4199))

You can set this stuff up anyway you want. Simply open the blindscan .py file and modify it to your liking.

[Megatron817]

I think you are right thuogh the blind scan >xml shows 11550 when it really did start at 11700. Better leave the start frequency 11700 then.
That is why it was faster because it started the scan at 11850.
Thanks!

[el bandido]

It would also be a good idea to use the correct lnb settings in Tuner configuration too.
Enigma2 NimManager defines Circular lnb as a 10750 l.o. Only C band and Circular lnb types are defined in the blindscan plugin. So the default in the blindscan plugin is universal lnb, and that is what the blindscan plugin will use unless the plugin "sees" a C band or Circular lnb type!

Here is where the blindscan plugin defines lnb types:

def SatBandCheck(self) :
pos = self.getOrbPos()
band = 'Unknown'
self.is_c_band_scan = False
self.is_circular_band_scan = False
self.is_Ku_band_scan = False
self.is_user_defined_scan = False
self.suggestedPolarisation = _("vertical & horizontal")
if band == "Unknown" and self.isLNB(pos, "c_band"):
band = 'C'
self.is_c_band_scan = True
self.suggestedPolarisation = _("vertical & horizontal")
if band == "Unknown" and self.isLNB(pos, "circular_lnb"):
band = 'circular'
self.is_circular_band_scan = True
self.suggestedPolarisation = _("circular right & circular left")
if band == "Unknown" and self.isLNB(pos, "universal_lnb"):
band = 'Ku'
self.is_Ku_band_scan = True
if band == "Unknown" and self.isLNB(pos, "user_defined"):
band = 'user_defined'
self.is_user_defined_scan = True
# if satellites.xml didn't contain any entries for this satellite check
# LNB type instead. Assumes the tuner is configured correctly for C-band.
print "[Blind scan] SatBandCheck band = %s" % (band)

[Megatron817]

I don't Know I did a blind scan 91w KU using circular found 5 Transponders 11 CH. then back to user defined found 8 Transponders 13 CH. Maybe some transponders came online during the second scan but anyway the frequencies are right both settings.

[Megatron817]

Did some more blind scans. Circular settings are working good so left if set circular. I maybe still having some diseqc hicups some scans still find more and some less but some of those signals are weak with just a 30" dish.