NewBe BLIND SCAN question.

[manitobamike]

Easy questions. What is a blind scan?
Ok I know what the purpose and outcome is and that different boxes seem to come up with different results but what is the technical procedure going on?
How does it determine what symbol rate(s) to attempt?
Does the transponder encode the SR and FEC into a known format packet and this is the basis for the blind scan to work from? I know the Video and Audio signal formats are transmitted out in a transponder packet leader once you get the proper freq, SR and FEC to decode.

While I'm asking, is there a known signal from each satellite that uniquely identifies it or do sat finders (and STB's) just look for a specific transponder freq to make a judgement call on the identity of a satellite?

 

[Lak7]

While I'm asking, is there a known signal from each satellite that uniquely identifies it ......

Not always. Some Sats have a TP that ID's the Sat - only a few.
The receiver does not really know where it's pointed - that's your job. Whichever Sat you have selected in the Scan menu is the Sat the receiver thinks it's pointed at.

 

[updatelee]

Some satellites have beacons, as mentioned, not many are in the c/ku band though.

Some satellites transmit valid NIT data on their tp's, lots dont.

UDL

 

[FaT Air]

https://en.wikipedia.org/wiki/MPEG_transport_stream

 

[. Raine]

Would be real nice if the sats. did have an identification beacon or transponder! 121 W Ku is the only one I can think of that does do that with the "Dish congratulation, you've found 121 W", or something like that.

 

[turbosat]

That beacon is nice to have, I remember when I had the old Viewsat Ultra, it would pop up that information on many of the ku satellites. And this Vantage 1100 box I have will do that on some, too.

 

[updatelee]

A video channel takes alot of bandwidth just to ident the bird. Valid NIT data takes very little data, would be nice to see. But most of what we're tuning is wildfeeds so they dont care less about us FTA'rs identing the right sat.

The always on stuff for the most part has valid NIT, not all which I dont understand, but alot does.

UDL

 

[Mr Tony]

121 W Ku is the only one I can think of that does do that with the "Dish congratulation, you've found 121 W", or something like that.

Back when Dish used 105 & 121 for locals they used those slates so the Dish customer service folks could verify what satellite you were aimed at
They had at one point slates on
61.5 (think they still do)
105 (gone as Dish abandoned that sat. They sublease it)
110 (think that got pulled. It use to say "You have a dish 500"
121 (still there)
129 (still there but scrambled)
148 (satellite blowed up years ago)

 

[manitobamike]

Ok tks for id answers but any takers on the blind scan techie question?

The Id question was prob easy.
Are there any electronic techies that know what the mechanics of blind scan are?

 

[updatelee]

I know I used to find the SR using my analog receiver's baseband out to my icom PCR1000. Where there was signal was the SR. ie if I had freq on 30,000khz that was the SR. I wouldnt be surprised if they did something similar considering all modern tuners use IQ output at the baseband anyways,

UDL