TNAP-6 Image Discussion

ArloG said:
Again. It's not why I want to scan it (107.3W). If I wanted to find it and knew there might be active transponders. Take, oh I don't know, 87W & 89W for instance. Like looking for those tasty wild feeds and cameras all around a ball field. Signal's there, can't scan for it. Well, actually you can. But not if Ray Charles is doing it for you. Yeah. Drivers, we can swap. Have anything to do with firmware in (what is it??) /lib/firmware?
Click to expand...
There are many variables in a satellite blindscan. So many variables that if you start looking at them, you will wonder how blindscan works at all. But it all comes down to the basics which have been pretty much discussed before.
Dish aiming
Satellite blindscan can perform no better than the signals it is given. For best results, have the highest signal possible before starting the scan. here are a few:
LNB Position
The lnb needs to be positioned properly and steady.
Dish surface
Warped or uneven dishes will cause blindscan issues.
Dish Hardware
The dish does not need to move at all during the blindscan and it does not need to vibrate.
Noise
Efforts need to be made to limit noise which includes using high quality switches and cabling.

All of that stuff has been talked about before. Most fta c band dish systems are 30-40 years old. Ideally these dishes would be replaced and have proper surfaces. But this stuff has an effect on blindscan results.
Also consider:
1 **Strong Adjacent Transponders:** High-power transponders mask nearby weak ones
2 **Intermodulation Products:** Non-linear mixing creates false signals
3 **Cross-polarization Interference:** Polarization isolation degradation
4 **Terrestrial Interference:** Ground-based transmitters in satellite bands
5 **Signal Quality Monitoring:** Track signal quality during scans
6 **Adjacent Channel Awareness:** Account for strong adjacent signals

It also helps to know how much signal is needed to get lock. Usually the hard-to-lock transponders are the ones missed in a blindscan. Take for example an 8psk transponder will need around 9.4 db(snr) to lock and about 10.4 db(snr) to return a clean, usable picture when the FEC is 5/6.

TNAP images generate scan reports each time a scan is performed of any type. These reports are designed to give feedback on how the antenna system is performing overall, along with the transponder being observed as Locked or Unlocked. A sample report is attached.

The 107w satellite location is noisy, and this is something else that needs to be considered when understanding why transponders are missed in blindscan.

A complete AI analysis of the driver used in Edision receivers is here:
el bandido

Thread 'Analysis of Avalink AVL6261/AVL62X1 Satellite Blindscan'

Attached is a highly technical analysis of Satellite Blindscan Implementation in the Avalink AVL6261/AVL62X1 De-modulator (Tuner). This information would apply to the Edision 4K series, Octagon SF8008 V2, and other Avalink AVL6261/AVL62X1 satellite receivers equipped with blindscan. This analysis was ran on what I had in a particular folder, which has modified files. So some described parameters may very slightly, but the bulk of the information should be the same. The attached report was written entirely by Claude Code (Sonnet-4 AI Assistant)

Very well written!!!
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There are things that can be done in terminal and command line to further understand blindscan, but no use in listing them when command line or terminal use is not understood. TNAP images provide detailed outputs of blindscans and transponder scans.

Shown below is a sports game on 87w ku. The transponder is 8psk, 5/6 FEC which means I have about the minimum signal needed to make the channel "usable". The blindscan that added it is attached.

87w-ku.webp
 

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Thank you for taking the time to detail what probably should be taken as granted in the system. Very cool.
I know this thread is about TNAP-6 in general. And although you have professed that the whole TNAP "idea" is to help and get people into the....hobby?...as easy and fluid as possible.
You have also included some pretty cool and "geeky toys" into it.
And apparently TNAP-6 is modeled from openPLI still. The Claude scoop from them is some reading that is right down my alley.
Carrier capture. That was the term I refer as signal. Same as a spectrum analyzer hooked to a modulation analyzer.

Which brings me to. After reading the AI document. Take 34W for example. Heck, throw in 40W too.
34W is circular polarized. I can snag and receive AFN. 2.5-3.2 dB when the leaves drop in the fall until spring.
The signal is weak bit and a blindscan populates a transponder and channel list without a depolarizer "slab"
And 40W. Same. But significantly stronger. Solid lock and scannning it is pretty impressive, considering.

Good points. Noise, etc on 107W. Perhaps I will try straight coax (with a coupler) to the respective Norsat and see what magic happens.
But the transponder and channel I get is strong. I mean strong. No reason a blindscan shouldn't pick up the transponder.
4164V is towards the upper limit of the lnb. But you wouldn't think somehow an auto "Carrier and symbol rate" capture would be brick-walled.
Especially when entering the parameters manually. Even when deviating frequency/sr in the entries in Signal finder. Strong signal.

Professed weak at terminal and command line skills. A cheat sheet or bookmark of "Common Linux Terminal Commands" is close by. I use them a bit. But I sure cannot type commands faster than the keyboard buffer can fill. Definitely would fail on an interview and having to type 120wpm on a Royal. A bookmarked page on dvbsnoop has made for hours of fun. But I don't memorize or learn that stuff. You know.

TNAP? A TBS USB tuner? Was wondering. Also one of the dvb programs that somewhere let you enter the E2 receiver's IP and port. Like you would with VLC. That lets you see the info from your receiver like, or semi-like, you and Enosat and others can do. Thoughts?

If the gods behave on this new format. Perhaps a search will give details on the things you mentioned above. Like looking at detailed blindscan info.
I mean I could search the file system I guess. Unless you hid a polymorphic hemimetal assistant inside to TNAP to help. Carl perhaps? I'll never call it Carl!!
Thanks man. Good stuff.
 
Lot's of people operate under the pretense that since a signal appears to be strong, then blindscan should find it. That is simply not True when you consider that blindscan also finds transponders that are way below the lock threshold in signal strength.

The enigma2 image in general cannot do much about what is found in blindscan, especially when a blindscan binary is used. The blindscan plugin in enigma2 acts as no more than an interface for the enigma2 blindscan binary located in /usr/bin of receiver files. A blindscan can be triggered using the terminal, thus eliminating the blindscan plugin which can be useful in debugging.

What enigma2 can do is enhance the search of transponders that are found. Every transponder has a search timeout for example. The transponder timeouts can be customized to favor channel rendering over speed. TNAP images has done this along with some other enhancements to make sure every available channel or service is logged. A recent blindscan of 105w using the MIO4K returned 2190 Channels ( TV = 113 Radio = 2077). See attached.

Sometimes video pids and audio pids are simply missed in a search or they are set in such a way that a regular receiver scan cannot find them. TSDuck and DVB Snoop could possibly help in this area, and do other things as well Attempts at designing plugins for these items are being made, but it is slow. Using AI technology helps in development, but that costs money, and just because you have an AI all cued up and ready to go doesn't mean instant results either. There is an art to using AI and it is not learned overnight. Things might get interesting though as the development of TNAP continues. We will see...

DVB Snoop Plugin:
dvbsnoop-plugin-menu.webp
 

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