I'm curious how you are supposed to find channels without blindscanning? Do some of the secondary software companies do the scanning? I'm really not sure how this works, but I need to get a box thrown together and get something setup in the next week or so.
Blindscanning
- Thread starter Ramthebuffs
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you need to know all the details about the transponders.. the freq, weather it's h/v/l/r, etc.
I sometimes blind scan with my coolsat then enter the data into my pc app
I sometimes blind scan with my coolsat then enter the data into my pc app
I also blind scan with my Pansat and input the frequency and symbol rate on my Twinhan PC card for HD and 4:2:2 feeds that my Pansat can not decode.
There are a few PC cards that can blindscan but I think they can not decode HD and 4:2:2, they are also hard to find.
There are a few PC cards that can blindscan but I think they can not decode HD and 4:2:2, they are also hard to find.
I'm no pro @ this sort of thing, I'm not exactly sure how transponders work and if they change etc. But could you just compile a big ass list of channels and not delete them out instead of manually entering everything all the time?
Also, how easy is it to manually enter these things?
Also, how easy is it to manually enter these things?
it isnt that easy...Here is why
News feeds reuse the same transponders all the time. But they have different symbol rates
So newschannel A may be at 12000 H 3978 (example...freq, pol, sr)
newschannel B may be at 12000 H 2170
newschannel C may be at 12000 H 6789
etc
etc
etc
There are a couple feeds for sports that keep the same info but those transponders get reused when said sports team is not playing. So I may scan and find the same frequency but different symbol rate.
News feeds reuse the same transponders all the time. But they have different symbol rates
So newschannel A may be at 12000 H 3978 (example...freq, pol, sr)
newschannel B may be at 12000 H 2170
newschannel C may be at 12000 H 6789
etc
etc
etc
There are a couple feeds for sports that keep the same info but those transponders get reused when said sports team is not playing. So I may scan and find the same frequency but different symbol rate.
With the Digistar/Digiwave 103G (Geniatech) there seems to be a downside to big ass lists. They are easy enough to create since the sanctioned programme ProgDVB uses ini files with details of transponders to be scanned. Those supplied, even by the Joshyfun site tend to stick everything in (BAL if that is what you are looking for).
However, as noted by a thread in the Mytheatre forum and in my own experience as well if the software cannot find a channel fairly soon in the sequence of transponders then it gets discouraged and gives up finding anything anywhere until after a cold reboot. I have found it more effective to reduce the transponder list to what you know is there and give the card something to get its teeth into.
The fact that it seems to occur with Mytheatre and ProgDVB equally indicates that there is something wrong at a lower level, say in the drivers.
Other cards may be different, YMMV. Even good blind scanning boxes like the Coolsat 6000 regularly fail to find such regulars as Montana PBS.
However, as noted by a thread in the Mytheatre forum and in my own experience as well if the software cannot find a channel fairly soon in the sequence of transponders then it gets discouraged and gives up finding anything anywhere until after a cold reboot. I have found it more effective to reduce the transponder list to what you know is there and give the card something to get its teeth into.
The fact that it seems to occur with Mytheatre and ProgDVB equally indicates that there is something wrong at a lower level, say in the drivers.
Other cards may be different, YMMV. Even good blind scanning boxes like the Coolsat 6000 regularly fail to find such regulars as Montana PBS.
I've been looking @ the skystar 2 2.6 and think I may try it. I've got a linux box that looks like it will do the job. Does anyone run a skystar 2 on linux? Would you recommend it? I don't really feel like buying another computer for just 1 job.
You might also check this thread about a new Technisat Skystar HD card that does blind scanning.
Do your homework for support, though. As with any new card.
Same as any FTA box - you got a list of transponders, turn the receiver lose to scan those, and then you have channel lists.
Blind scanning comes into its own when you are hunting feeds on unknown transponders or with unknown transponder specs.
Yea, I suppose if a service changes its transponder specs, you might be left high and dry.
Big deal - that's the exception, not the rule.
And of course, if you are aiming your first dish, find a bird, but aren't sure which one you've got, then blind scanning is great.
But it's not mandatory - there are other ways to go.
Kinda like saying, I can't drive on the freeway without a turbocharger.
Yes, you certainly can!
Do your homework for support, though. As with any new card.
The question wasn't clear , but for regular birds, the existing transponder lists are generally just fine.
Same as any FTA box - you got a list of transponders, turn the receiver lose to scan those, and then you have channel lists.
Blind scanning comes into its own when you are hunting feeds on unknown transponders or with unknown transponder specs.
Yea, I suppose if a service changes its transponder specs, you might be left high and dry.
Big deal - that's the exception, not the rule.
And of course, if you are aiming your first dish, find a bird, but aren't sure which one you've got, then blind scanning is great.
But it's not mandatory - there are other ways to go.
Kinda like saying, I can't drive on the freeway without a turbocharger.
Yes, you certainly can!
The docs for the Skystart 2 2.6 show this for auto scanning:
"Scan for transponders
In this case you have to enter the start and end frequencies, the step size and up to
three symbol rate values, which should be tested. After these values are entered,
press "Search & Scan" to start the process."
I would be interested to know if the 2.3 version does something different.
This raises the whole question of what blind scanning is our should be. Plainly what is happening with any blind scan you have a start and stop frequency and loop between these points at specified increments. The finer your steps the better the scan and the more chance you will get all of the wild transmissions (and the longer it will take). On the Coolsat the 'full' and 'detail' settings presumably control this, and it must be that I can never blind scan Montana PBS because the frequency or S/R fall between two scans that do not overlap enough.
When it comes to symbol rates, are there specified points at which symbol rates are chosen, or can they be anything on the continuum from 0 to 500,000+?
"Scan for transponders
In this case you have to enter the start and end frequencies, the step size and up to
three symbol rate values, which should be tested. After these values are entered,
press "Search & Scan" to start the process."
I would be interested to know if the 2.3 version does something different.
This raises the whole question of what blind scanning is our should be. Plainly what is happening with any blind scan you have a start and stop frequency and loop between these points at specified increments. The finer your steps the better the scan and the more chance you will get all of the wild transmissions (and the longer it will take). On the Coolsat the 'full' and 'detail' settings presumably control this, and it must be that I can never blind scan Montana PBS because the frequency or S/R fall between two scans that do not overlap enough.
When it comes to symbol rates, are there specified points at which symbol rates are chosen, or can they be anything on the continuum from 0 to 500,000+?
True "blind scan" is more that just finding a signal and attempting to lock it using different symbol rates. Using that method would be considered a brute force approach and would take a very long time as symbol rates are often anywhere from 1 to 45Ms/sec. A true blind scan would probably first look for peaks by sweeping through the entire frequency spectrum, in a similar manner but after finding those peaks, which would represent potential signals, would then probably use something akin to the shortwave method for determining symbol rate. As for why some receivers like the coolsat may have an option for optimizing the blind scan for certain symbol rates, it's probably changing the IF bandwidth filtering. If one uses the shortwave method to find symbol rates, it's sometimes advantageous to use an analog receiver with a selection of different IF bandwidths, as sometimes there are situations where multiple thiner carriers are packed onto a single transponder. In situations like that a narrower IF filter will help isolate the carriers from one another when attempting to determine the symbol rate for each.
Very interesting, Stefan, thanks. The comment about known stops along the S/R continuum was prompted by the dialog box in ProgDVB which offers a half dozen or so values. ProgDVB will also allow 0 as a value in which case it will still find a signal if there is one to be found, doing a quasi 'blind search' of some kind.
With regard to speed, I was assuming that since we are talking about GHz oscillating transmissions that tests could be done very quickly, evidently a false assumption.
It occurs to me that all I have to do is get the list from Mike Kohl's site and run an analysis of the S/R column to determine if there are 'popular' values. My key for further reading seems to be 'bandwidth filtering'. Now right after the question "Does this receiver do blind scanning?" comes a new question "What kind of blind scanning is that?"
With regard to speed, I was assuming that since we are talking about GHz oscillating transmissions that tests could be done very quickly, evidently a false assumption.
It occurs to me that all I have to do is get the list from Mike Kohl's site and run an analysis of the S/R column to determine if there are 'popular' values. My key for further reading seems to be 'bandwidth filtering'. Now right after the question "Does this receiver do blind scanning?" comes a new question "What kind of blind scanning is that?"
2.3 has a chip which auto tunes the SR rate, so it can do a blind scan of a whole satellite in 60 seconds.
It is not perfect, missing some freq's.
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