Blind scan renders duplicate channels

W

WilburSmith

New member
I installed today a Quad Polar Legacy 4 O/P LNB.

When I went to view channels nothing was available although channels were listed and the dish moved from satellite to satellite. I did a rescan and the channels came back. But for some odd reason they come in duplicate. This happens with both my Edison receiver and Koqit receiver. This is strange.

At first I was thinking that I was getting SD & HD versions of the same channel but this isn't the case.

Has anyone seen this beofre? What's this called? Can it be fixed?

Thanks!
 
Yes I did. I think the problem is being caused by quad lbn because when I had a universal lnb in place no issue. When I changed then both Edison and koqit stbs were effected with same issue.
 
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It's just a guessing game without some decent information about the lnb and the way the receiver(s) are setup.

What is the make/model of the lnb? A google search of Quad Polar Legacy 4 O/P LNB is useless.
https://www.google.com/search?q=Qua...gAfEBqgEDMi0xuAEDyAEA-AEC-AEB&sclient=gws-wiz

What polarity is being duplicated? One? Both? or do you know?
What particular satellite has this problem? An example satellite would help.
A channel scan log is created for each scan if you are running a TNAP image on the Edision. The scan log is designed to assist in problems such as this and can be found by default in the /tmp folder of receiver files. It would help to post this file as it contains lots of information, but don't confuse it with the blindscan transponder log which is also in the /tmp folder.

What are the antenna settings in the receiver?
Not much of a way to help you without knowing this information besides guessing. A screencap or screenshot can be taken with the Edision that shows the antenna settings in the receiver. This is easy and only takes a couple of minutes to do. You may list the antenna settings as an alternate to a screenshot.

What is installed between the receiver and lnb? Switches? Ground blocks? Other?
A brief, precise description of what is installed between the receiver and lnb helps. It also helps to know if you are trying to run two receivers off the same lnb.
 
Hi, Below are the answers for your questions.

What is the make/model of the lnb?

Invacom Quad QPH-031 KU LNB 2 Linear & Polar Outputs
LO 10.76/11.25

What polarity is being duplicated? One? Both? or do you know?

Both 'V' parity is being duplicated. I confirmed this via transponder info menu.


When blind scanning polarisation set to:

Per 77W

Verticle and horizontal = I get duplicates of each tv channel but not radio
Verticle = I get duplicates of each tv channel but not radio
Horizontal = No Transponders were found (Probably because no H transponders exist)


What particular satellite has this problem? An example satellite would help.

77W See above



A channel scan log is created for each scan if you are running a TNAP image on the Edision. The scan log is designed to assist in problems such as this and can be found by default in the /tmp folder of receiver files. It would help to post this file as it contains lots of information, but don't confuse it with the blindscan transponder log which is also in the /tmp folder.

There was no channel scan log to be found. I'm using OpenATV 7.3 but this is the blindscan.xml in case.



<?xml version="1.0" encoding="iso-8859-1"?>

<!--
File created on Friday, 13 of October 2023, 12:14:56
using osmio4kplus receiver running Enigma2 image, version 7.3,
build 20231007, with the blindscan plugin

Search parameters:
Tuner A: Availink AVL6261 (DVB-S2X)
Satellite: 101.0W Ku-band T9S/T16 & SES 1
Start frequency: 10700MHz
Stop frequency: 12750MHz
Polarization: vertical and horizontal
Lower symbol rate: 2000
Upper symbol rate: 45000
Only save unknown tranponders: no
Filter out adjacent satellites: up to 3 degrees
Scan duration: 257 seconds
-->

<satellites>
<sat name="101.0W Ku-band T9S/T16 & SES 1" flags="0" position="2590">
<transponder frequency="10705000" symbol_rate="3650000" polarization="1" fec_inner="3" system="1" modulation="1" />
<transponder frequency="10906000" symbol_rate="5000000" polarization="1" fec_inner="0" system="0" modulation="1" />
<transponder frequency="10933000" symbol_rate="5000000" polarization="1" fec_inner="0" system="0" modulation="1" />
<transponder frequency="11001000" symbol_rate="20000000" polarization="1" fec_inner="0" system="0" modulation="1" />
<transponder frequency="11756000" symbol_rate="5000000" polarization="1" fec_inner="0" system="0" modulation="1" />
<transponder frequency="11783000" symbol_rate="5000000" polarization="1" fec_inner="0" system="0" modulation="1" />
<transponder frequency="11850000" symbol_rate="20000000" polarization="1" fec_inner="0" system="0" modulation="1" />
</sat>
</satellites>


What are the antenna settings in the receiver?

Tuner setup - Advanced setting

Configuration mode: Advanced
Satellite: 77W

LNB = LNB 1 OR 2 OR 3 (because you have 3 lnb’s)
Priority = Auto
Type of LNB/Device = Universal LNB
Voltage mode = Polarization
Tone mode = Band
Increased voltage = No
DiSEqC mode = 1.2
Fast DiSEqC = No
Yone Burst = None
DiSEqC 1.0 command = Port B
DiSEqC 1.1 command = None
Sequence repeat = No
Use USALS for this sat = Yes
000.000
West
000.000
North
Extra motor options = No
Force Legacy Signal stats = No


What is installed between the receiver and lnb? Switches? Ground blocks? Other?

Pansat 4X1 DiSEqC Switch
LNB 1 Port B
LNB 2 Port A
LNB 3 Port C

Priority switch


It also helps to know if you are trying to run two receivers off the same lnb.

I use a priority switch and more than one receiver can't be used at same time.



Other:

Satelite moves from satelite to satellite normally
 
TNAP is the only image that currently makes a channel scan log.

The l.o. for that lnb is 10750 MHz for linear. Apparently you are using Universal settings.

Your information is confusing. The blindscan log you provided is for 101w ku, but you say this is for 77w???

Anyway, try using the Circular LNB setting instead of Universal in the Edision antenna settings and you should be fine. Delete what you have and re-scan.
 
I solved my issue!

On my Koqit I change the universal frequency to 10750. As soon as I did that all my previous scans were restored and the duplicates could be deleted.

On my Edison you are not allowed to change the setting to Circular LNB, especially when that's NOT what we are dealing with. It must remain as Universal LNB!

Doing the blind scan is another matter. Here I kept the the Scan from frequency as 10700 and the Scan stop frequency as 11700 (formerly 12750). My reasoning was based on this:

When scanning for FTA (Free-to-Air) satellites in North America, the frequency range typically covered by a standard LNB is from 11,700 MHz to 12,200 MHz. However, there are universal LNBs that cover a broader range from 10,700 MHz to 12,750 MHz. This universal range is divided into two bands, and a 22kHz signal is used to switch between these two bands. Some satellites that are receivable in North America use the lower band, which ranges from 10,700 MHz to 11,700 MHz source.

I scanned 77WEST and now the duplicate channels disappeared.

I guess a good question to ask now is what percentage of North American satellites can be found within: 10,700 MHz to 11,700 MHz source.
 
PS. In the advanced options the 'Type of LNB' can be changed to USER DEFINED

Then these settings need to change. Currrently they are:

LOF/L 09750
LOF/H 10500
Threshold 11700

Could these be changed to

LOF/L 10700
LOF/H 11700
Threshold

What should threshold be then?

If changes are applied here then they effect all satellites system wide, whereas under blind scan its more specific to a certain satellite if a change made there.
 
Correct, Change all three to 10750 Or as I said earlier, use Circular.

We can look at the file where these settings are managed in the link below.
https://github.com/openatv/enigma2/blob/master/lib/python/Components/NimManager.py

Lines 466-469 show how Circular lnb is set in enigma2 for OpenATV:
elif currLnb.lof.value == "circular_lnb":
sec.setLNBLOFL(10750000)
sec.setLNBLOFH(10750000)
sec.setLNBThreshold(10750000)
Click to expand...

So all three to 10750 or use Circular. Either one should do the same thing unless OpenATV has changed their blindscan coding.

Other lnb settings will work, and it does not matter what you use as long as you are satisfied with the results.
 
The threshold is the frequency at which the receiver tells the LNB to switch to high band, it can be anywhere from 11,500 to 11,700 (possibly a little higher, as the highest frequency on the satellite is less than 13,000).
Standard (user defined) ku lnbf's use 10750 for all 3 selections of LOF/L, LOF/H, & thresh.
Voltage changes polarization so therefore it would be set to Polarization.
If no tone switching is used for high/low band then that is set off.

Note that Polarization in the .xml has 0,1 for linear and 2.3 for circular polarization. And some of mine for C band have been modified as I've recently tried "the slab", or depolarizer.
To answer a previous question a recent scan is here. There is a bit of housekeeping to maintain the satellites.xml file.
Some copy/pasting (deleting lines in the master .xml) from the saved scan to the Tuxbox file.
If you also look. Only satellites visible in my arc are included and all others are trimmed out. It would be obvious that versus scrolling through every single sat. in the original installed list. It is better that way.
Further. There may be many "left behinds" as although transponders may be shut off. They can also be turned back on.
Much faster in Signal finder to see so. And channels on them (in TNAP and ViX) can be seen. Rather than performing a blindscan every time.
The upload privileges prevent .xml files so you can rename the extension. It's kind of a freebie blindscan file you can pick and choose from.
Always backup first.

View attachment satellites.txt
 
There are many ways to enter antenna settings in enigma2. But I think it is best to use the same settings the image was coded with, which is the same entry for all lnb frequency entries unless a dual l.o. lnb is being used. So a lnb with a single l.o. of 11250 would be entered three times in antenna settings.
Here is a NimManager sinippet:
Screenshot from 2023-10-14 13-27-32.webp
 
Changing or altering the satellites.xml files can present its own set of problems. The channel file named lamedb is tied to the satellites.xml file for satellite entries. The lamedb file may become corrupted or unusable for the most part when a new satellites.xml file is introduced, so it is a good idea to backup the lamedb file before loading a new satellites .xml file.

Different satellites.xml files and channel files can be packed as an .ipk file which the enigma2 receiver can install. These .ipk files can be added to the feeds where they can be easily accessed and installed.

1_0_1_3_2E5_0_EEEE0000_0_0_3_20231014132148.webp
 
I agree and actually had to give it a 2nd thought.
When initially installing a new image and setting up the tuner for the first time. And notice all of the sats. I never will get. I'll drag my .xml over into /etc/tuxbox. And give 'er a reboot.
That's done right after I set up the first sat. and save the config. Kind of gives me a pointer should I choose to c/p the nims lines in a saved /etc/enigma2 settings file on my pc from FTP.
Using ssl and throw it an init 4 first. Edit and save settings in Notepad++. And then a customary cold boot. A full list of tuner settings is done in a fast-setup way.
Backup first. Depending on different images and Linux versions it has crapped out once or twice before.
3rd thought, took a peek in my saved lamedb on the pc. It contains the same .xml as in tuxbox. So that's cool. I use E-Channelizer just because I do.

My .xml has a few "huh??" sat's and tp's in it. Kind of my own workspace. 131 has 2 entries. One with 131*. From back when a few tp's on it needed a bump of the dish mover to peak the channels.
So they auto-tuned (no...not like Cher or Britney) the dish to peak, sort of.
I'm still learning. Didn't want to spread bad juju.
 
The Invacom QPH-031 is a decent performing lnb on most offset satellite dishes. The QPH-031 was popular and useful some 10-15 years ago when DishNet had a few channels that were not scrambled. You will probably have a hard time finding anything useful to watch on the circular side today because everything is scrambled except maybe Dish advertisements.

The Invacom QPH-031 is a heavy lnbf, and the weight of it can become a problem where there is snow and ice. This lnb is heavy and bulky to begin with, and it gets a lot worse in the weight department when snow and ice is added. This lnb is heavy enough to distort the face of some satellite dishes, especially with ice and snow. the lnb arm may also sag or bend on some satellite dishes that are poorly supported or have no side supports for the lnb arm or feed. Homeowner satellite dishes are usually a bit flimsy and not well built. Most commercial type satellite dishes would not have any problem with the lnb weight.

Another draw-back to the QPH-031 is the weather proofing was not very good and the cover will crack or break as shown below. A little more thought or care by Invacom would have made this problem less likely to happen or at least take years longer to happen. I ran the the QPH-031 shown below, and enjoyed it, but the drawbacks and problems need to be understood. My 1.2 meter dish didn't seem to have any problem holding this lnb, but the Atlanta, Ga. area doesn't get much snow or ice either.

20231014_225527.webp

20231014_225534.webp

20231014_225538.webp

20231014_225543.webp
 
Did the lens crack because of the reflection of the sun off a white dish and into the lnb? I wanted this lnb because you never know what you may find one day.
 
If my window of satellites is from 77W to 103W how can I get rid of the ones I don't need to see?

I guess I was wrong but I was lead to believe that editing the satellites.xml do what I want while adding custome sats on an as needed basis,
 
Wil. I do not have 77W in my list. Could you attach your blindscan results for it?
Remember. It will have a .xml extension. So change it to satellites.txt to attache it here.
Always use Notepad++. Very important.
Just one wrong space, tab, incorrect entry can bork an edited .xml file.
And your receiver won't be happy. So perform a backup first always.
The file must be formatted perfectly for it to work. I have a file ready from 75W to 103W c & ku.
A search for Enigma 2 satellites.xml file format or configuration should tell you a bit more.
When you send your file and get mine back, you'll see a little of what was done.
 
Regarding the OpenATV blindscan the LNB can be changed here too but I'm lead to believe that here and can keep vertical and horizontal in place without changes. Is that correct?
 
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