Blind scan renders duplicate channels

[WilburSmith]

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!

[Executive]

Did you do a software update recently on your Edison?

[WilburSmith]

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.

[el bandido]

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.
[Only registered and activated users can see links. ]

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.

[WilburSmith]

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 &amp; 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

[el bandido]

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.

[WilburSmith]

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.

[WilburSmith]

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.

[el bandido]

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!

LOL!

Apparently, you know more about these receivers than I do. But just in case, you might want to read the thread FROM 2019 in the link below. Especially post #3 on page 1.

[Only registered and activated users can see links. ]

[WilburSmith]

So the three data points I asked about above all get changed to 10750....