Correct Settings for Blindscan in Enigma2 for North America

The blindscan plugin that is used in enigma2 receivers today was created by a person that is unknown to me.

The blindscan plugin that is used in enigma2 images today was modified by, and is maintained by Huevos. The original blindscan plugin did not have c band capabilities. Huevos added the c band capability, and more recently add Ka bands, and some other tweaks to the blindscan plugin. The work and maintenance of the blindscan plugin by Huevos has helped us tremendously in North America, and is appreciated!

The blindscan plugin is really based on one lnb, which is the Universal model, and has a pair of l.o. frequencies that are 9750, and 10600 MHZ. Code has been added which allows c band (5150 MHZ), standard ku (10750 MHz), circular (11250 MHz), and some others such as ka to work. But it is important to remember the original design of the blindscan plugin which is universal lnb, because code to make the other lnbs work is based on the origina, dual l.o. universal lnb.

There are usually several different ways to setup a lnb in the receiver where it will work in blindscan, and it could be said that there are three types of settings which are: My Settings, Your Settings, and the Correct or Suggested Settings. Really it does not matter what you use so long as the receiver functions as you would want or would like, but for this thread, we will try to focus on and discuss what the correct blindscan setup and the correct lnb settings which are based on the blindscan code written mostly by Huevos.

Universal lnb's have a high and low band with 10600 MHZ as the l.o for the high band, and 9750 MHz l.o. for the low band. The universal lnb switches bands by using the 22KHz tone.
LNB's that have a single l.o. such as a common c band lnb will be ran through the blidnscan plugin in the low band, with coding in the plugin changing the transponder frequencies so they read correctly for us. It is not a good idea to use a 22KHz tone switch for connection of two single band lnbs that are to be blindscanned. The 22KHz tone tells the blindscan to switch to the upper universal band. Some receiver such as the OSMIO4k will ignore this on a single band lnb, but other receivers may try to switch bands when a 22KHz tone switch is used which will result in transponders being displayed wrong and missed transponders. So if possible, eliminate any 22KHz tone switches for single band lnbs that you want to blindscan. Or at least understand what can happen if a 22KHz tone switch is used on some enigma2 receivers that blindscan.


There are several other settings for blindscan that will be easier to cover or explain using screencaps, so the next few posts in this thread should contain a few screecaps or pictures with written explanations. There are a lot of settings or combinations that many users do not know about or do not know why they exist. The blindscan plugin contains filters that will look at the transponder list for satellites close by, and delete those transponders if they are found in a blindscan. Other filters check for duplicates, and may remove transponders that are found closer than 4 MHz apart if certain conditions exist. I will try to explain all of this to the best of my limited ability, then open this thread for questions or comments. EB

In a single tuner receiver, such as the OSMIO4K, each lnb will need a different number. For example, I use lnb1 for Universal LNB as shown below.
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The 22 KHz tone is set to Band for Universal type so the lnb can be switched from low to high band as needed.


Any lnb with a single l.o. of 5150 will be considered to be a C-Band lnb in the receiver. Shown below is my settings for the C-Band LNB.
The 22KHz tone is set to Band, which does not seem to hurt anything because the blindscan plugin will scan this lnb using the low band. Remember, the blindscan plugin is setup as a two band scan which are low and high. Single l.o. lnbs are setup on the low band in the blindscan plugin.
It would not be a good idea to use this lnb for blindscan and also have 22 KHz set to on. However, I have done it on the OSMIO4k and did not notice any problems.
Suggested setting for C-Band LNB is 22KHz tone set to OFF.
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A linear ku band lnb with a l.o. of 10750 is commonly referred to as a Standard LNB in North America. This type of lnb needs a bit of an explanation.
A few years ago, we managed to get the 10750 l.o added to the enigma2 blindscan plugin as a Circular lnb. The code that allowed this lnb to work in blindscan was a royal mess. Huevos straightened the coding mess out, and added some user defined settings to the blindscan plugin. The reason the Circular lnb type was used is because it was already defined as having a 10750 l.o. in other parts of enigma2 image. So adding the Circular 10750 l.o. lnb setting into blindscan was not as hard when compared to adding a lnb type such as "Standard", which is not defined in enigma2.
In all the melee of getting the code for the Circular lnb presentable, and adding the User Defined lnb settings for blindscan, Huevos pointed out that the Circular lnb setting is for use in Russia, and there are even coding remarks that point to this.

The Circualr LNB setting may be used for a 10750 l.o. lnb, but for the reasons above, it is suggested to use User defined settings for this lnb, and enter 10750 3 times as shown below. A 22KHz tone switch is not suggested for use with a 10750 l.o. lnb. A 10750 l.o. lnb should work fine with the 22KHz tone set to Band.
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There are many different ways the 10750 lnb can be configured, and some images customized for North America may have a Standard lnb listing, which would be okay to use for a 10750 lnb.
Circular lnb type will also work now on a 10750 l.o. lnb, but if coding for it gets changed, which is possible at some point, then the Circular setting for a 10750 lnb may not work in our part of the world correctly.

It is also possible to split the bands when using the Universal type lnb. Normally it takes 4 steps for the blindscan to complete when using the Universal lnb. These 4 steps are necessary when looking for frequencies below 11700 MHz. But on satellites that do not have any transponders below 11700 MHz, only two blindscan steps are needed. To make the Universal lnb blindscan in 2 steps, and have a low frequency range of 11550 MHz, use the User defined settings shown below. 22KHz tone may be set to Band.
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Other User defined lnb types are possible. I tested a circular 11250 l.o. lnb, and it blindscanned correctly. Ka band lnbs should also work.

Any image that we modify for use in North America will probably have the blindscan plugin modified so it will find the maximum transponders for the satellites. The modifications will be based on using a c band dish that is 3 meters or larger, and a ku band dish that is 1 meter or larger. There are blindscan features available that may cut duplicate transponders on small dishes such as a 1.2 meter dish for c band. These features are deleted or at least hidden in North America modded images in order to lessen confusion. A typical blindscan menu that is modded for North America is shown below.
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The idea here is to make the blindscan menu easy to understand and use. It is also set to give the maximum amount of transponders that the tuner can find.

Blindscan plugins that have not been modded for North America will have more features and options. However, these extra features can cause loss of transponders during a blindscan. Shown below is a typical blindscan plugin with one extra feature added. I will try to explain what the menu options do, and how they effect the outcome of the blindscan.
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The first few menu options for blindscan are not difficult.
There are two scan types.
(1) Scan for channels will look for transponders, then scan the transponders for channels.
(2) Scan for transponders will look for transponders, then stop and display what is found, and wait for user input. Each individual transponder that was found can be scanned or not.

There are entries for start and stop frequencies. I rarely change these entries because the plugin code sets the start & stop frequencies for the maximum frequencies the lnb can give. Adjusting these values will not speed up or slow down the scan by a noticeable amount in the MIO4K receivers.

Polarization types can be changed. A single polarity may be scanned.

Start & Stop values for the symbol rate may be entered. I usually set these values for the lowest and highest values that the tuner can handle.

Clear before scan will erase any stored channels or services from the lamedb file for the satellite.

When "Only free scan" is set to yes, Any channel or service that has an encryption flag will be ignored.

These menu items are the easy ones. The others will take a bit more explaining.

The blindscan plugin code assumes that there is a good satellite file in the receiver. The satellite file name is satellites.xml.
The satellites.xml file is updated regularly, and there are people in Europe and other parts of the world that keep the satellites.xml file accurate for their area, or for the satellites that they frequently use. Few updates are sent to Lyngsat for North America as compared to other parts of the world, so the North American satellite file is almost always outdated.

There are checks and filters built into the blindscan plugin.
One check is to compare what transponders have been found to what is listed in the satellites.xml file. Since it is assumed that the satellites.xml file is correct, any discrepancies in the compared transponders will be deleted, and the information for the compared transponder that is in satellites.xml file will be used. In other words, the blindscan plugin looks at the satellites.xml file and takes information from it. This is great if the satellites.xml is current, but not so great for North America because the satellites.xml file for the satellites we use is almost always out of date.

One filter in the blindscan plugin is to look at the found transponders and remove any duplicates from the found transponder list. The problem with this filter for North America is some of the duplicate transponders are not actually duplicates! Two easy examples of this can be found on satellite 101w C band, and 95 west, C band. If the blindscan filter is set to operate normally, transponders on both of these satellites, and transponders on other satellites that are close together, and have similar symbol rates will be deleted from the found transponder list.

Blindscan works in two steps.
Step 1 is to locate transponders, check them for errors, and make them into a list.
Step 2 is to scan the transponders that were found in blindscan for channels or services.
Now we can look at the rest of the blindscan menu settings.

"Don't scan satellites.xml transponders" Means exactly what it says. When this entry is set to "yes", transponders for the scanned satellite that are located in satellites.xml will be deleted from the found transponder list. I usually have this entry set to No.

Note:
I have made a modified entry that says "Don't scan lamedb transponders" When this entry is set to "yes", transponders that already have channels stored in the receiver are not scanned. Any transponder that has channels saved in the lamedb channel file for the satellite being scanned is deleted from the found transponder list. I made this entry so I would not waste time re-scanning transponders that I already had channels for. This entry is not in any blindscan plugin that we currently use, and I do not know if anyone else could use this feature or not.

The last three entries on the blindscan menu is where you can really gain or lose transponders, so another screencap will be shown for them.

Two of these entries are normally set to "No". I have them set to "Yes".

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"Disable sync with known transponders" Is asking you if want the transponders found in blindscan to be checked against the transponders for the scanned satellite that are in satellites.xml? In other words, "Do you want to use the transponder information in satellites.xml or the transponder information that the receiver found? I have this set to "yes" because I want it disabled. The MIO does a great job of finding transponders with correct information.

"Disable remove duplicates" is simply asking you if you want the duplicate transponder check removed. I also have this set to "yes" If this entry is set to "No", then the blindscan plugin will run code that will remove any transponder that it thinks is a duplicate. With this entry set to "No", you are almost guaranteed to lose transponders on several satellites when blindscanning, with the two most common being 101w C band, and 95w C band.

The 'Filter out adjacent satellites" entry looks at the satellite.xml file, and removes any found transponder that is in the satellites.xml file for satellites up to 3 degrees in each direction. I usually have this feature set to "No", but some with undersized dishes such as 1.2 meters for C band may find this entry useful.

To review, The blindscan plugin has checks and filters built into it. These checks and filters are still useful in some situations, and are almost mandatory in some of the older receivers. As our tuners get better, the checks and filters are not needed as much.

The blindscan plugin is designed for many different receivers, so it has many different options or entries. I am sure that it complicates for some, and confuses others. But things are much easier once you understand what the entries or features are there for in the blindscan menu, and understand how to correctly set the lnb up in the receiver.

There are three easy ways to lose transponders in a blindscan.
(1) Use the wrong settings for the lnb.
(2) Use incorrect settings for your system in the blindscan menu.
(3) A combination of 1 & 2 listed above.


Any comments or improvements to the information in this thread is welcomed. EB

Thanks, good write-up .... s/b a sticky for fast reference. I pdf'd the thread for quick info.

Shown below is a good example of what we want in a blindscan, or at least what we want the blindscan to be capable of.
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You cannot blindscan a group of transponders like that unless the duplicate check in blindscan is disabled. Some of the transponders shown are around 2 MHz apart in frequency spacing and are about identical in polarity, symbol rate, fec, type...etc. If the duplicate check that is in blindscan sees this group, it would delete some of them.

There is also a duplicate check built into the enigma2 image. This duplicate check is active anytime a group of transponders is sent to Service scan for a channel search. Enigma2 images used to delete a pair of transponders that were almost identical like the ones shown above, The only way you can see this is to know how many transponders were sent to Service scan to be checked for channels, and then count how many transponders actually get scanned. This is why you see the number of transponders scanned out of how many were sent to be scanned in the Service scan that I modded. if nothing is deleted, the numbers will be the same, such as "25 of 25 transponders" scanned. If enigma2 deletes something, the numbers will not match.

Currently, most enigma2 images have the duplicate transponder check set to allow anything above 2 MHz spacing to be scanned, and anything below 2 MHz in spacing will result in one of two transponders being deleted. But several months ago when I last checked, there are some images that will delete one of two transponders that are found less than 4 MHz apart. Again, the only way to catch this is to know how many transponders are supposed to be scanned as compared to how many were actually scanned.

To put this another way, there are two checks for duplicate transponders in enigma2 when a group of transponders will be scanned. The duplicate transponder check in blindscan can be turned off, but the duplicate transponder check in enigma2 cannot.

Here is the same satellite scanned using modded image(TNAP)
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Here is the Free scan results.
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15 out of 16.
Blindscan found 16 transponders, but enigma2 deleted one of them as a duplicate. (The duplicate transponder check in blindscan is OFF.)

Blindscan generates a transponder file after the blindscan finishes and puts this file in the /tmp folder of the receiver. It has been this way for years.
The modded SatDreamgr image we call TNAP generates a report after the Servicescan completes. The reports are generated for satellite and ATSC. The Service scan report is alos stored in the /tmp directory of the receiver, but provisions are made to store both the blindscan and the service scan reports on an usb drive if proper folders are made for them. The /tmp folder in the receiver is dumped or cleaned during a reboot of the receiver.

Both the Blindscan report and the Service scan report are designed to be viewed using Notepad++ or another decent .xml editor. Below is an example of how to use these files or reports.

Our example is a blindscan of 95w that returned 20 transponders.
The Service scan was sent the 20 transponders from the blindscan, but enigma2 deleted one as a duplicate.
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We can look at the blindscan file and the Service scan report to find out what happened.
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From above, we can see tp 3966 was scanned, and tp 3967 was deleted.
TP 3967 is manually scanned since it was deleted, with this as a result.
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We cannot really ask the image makers to do anything about this because if you go any less than 2 MHz today on the duplicate check, then you will probably end up with some duplicate channels on other enigma2 receivers. At least we have information available from the scans to tell us what happened or what was deleted. Sometimes it pays to look when the number of blindscan transponders is different than what was scanned.

The files or reports shown above are attached. This was a "free" or unencrypted search.