Differance between a blind and a Standard Scan

Background:
The satellites (birds) transmit the signals to us on Transponders (TP's). Each Transponder has its own frequency unique to that bird (AKA Transponder Frequency in Receivers Satellite setup screen). The Transponder frequency can carry a number of TV/Radio channels or other non-TV/Radio Channels, NOTE: Not all TP's are TV/Radio, and do NOT show up as active, on the FTA receiver . With all entertainment birds for each transponder there are 2 polarities, called Vertical and Horizontal, and doubles the TV/Radio channels for each Transponder. The owner or operator of the bird can program which Transponder, channel and polarity that any given TV/Radio channel is on. They make frequent changes to this line-up for various reasons.

Blind Scan: When you blind scan, your receiver locks onto the bird and scans for Transponders, when it finds a Transponder, It puts into the receivers memory, the data for the found Transponder. Then the Receiver using the saved Transponder data, scans each of the saved transponders for the TV/Radio channels. These are the channels that we sort by Station IDentfication number (SID) and know as the channel numbers on our Receivers.

Standard (Auto) Scan: The Receiver does NOT scan for Transponders, it uses a list of Transponders that is in the software that has previously loaded (.bin's). It uses this list of Transponders to scan for the TV/Radio channels.
If the software load has a current list of the Transponders you are OK. If the list is outdated, you may not receive all channels available on that bird, thus a blind scan would be in order, to update the receivers transponders memory.

Why a blind scan is better
Upon receiving my new receiver on 2007/10/19, I loaded it with the current .bin that was dated 7 days ago.
I set it up to receive Bev 82/91 and Dish 110/119.

Then I did the Standard Scan, the results were;
Satellite - TV/Radio; Nimiq2 82W - 72 TV/2 Radio, Nimiq1 91W - 317 TV/47 Radio, Echostar 8,10 110W - 325 TV/4 Radio, Echostar 7 119W - 302 TV/133 Radio

With a Blind Scan, the results were;
Satellite - TV/Radio; Nimiq2 82W - 77 TV/2 Radio, Nimiq1 91W - 335 TV/48 Radio, Echostar 8,10 110W - 333 TV/4 Radio, Echostar 7 119W - 341 TV/160 Radio

For Bev a increase of 24 channels (5%), and Dish increase of 74 Channels (9%)

Many people mistakenly assume that you should never do a blind scan. This is based on the fact that alot of people are using DishPro technology and as a result are getting blind scans that consist of duplicated channels.

First, it is important to understand what DishPro does and how it differs from Legacy (or "Standard"). Each satellite has a frequency range of 500 MHz. For Dish/BEV-type satellites, your LNB receives 12200-12700 MHz. For most FTA satellites, the LNB receives 11700-12200 MHz or 3700-4200 MHz. Your LNB converts those frequencies down to the 950-1450 MHz that your receiver operates at.

If you look at the spec sheet in your receiver manual, you'll see that your receiver's input frequency is 950-2150 MHz. So in addition to the standard 950-1450 MHz band, you have a secondary 1650-2150 MHz band that is normally not used unless you have a universal LNB.

Echostar took advantage of this unused frequency band and created a technology that placed all left-hand ("horizontal") polarized frequencies in the upper band and left all right-hand ("vertical") frequencies in the lower band. All frequencies in the upper band are converted in such a way that all frequencies appear to be "vertical".

When you do a blind scan, your receiver searches everything from 12200 to 13500. First it does a horizontal sweep and then a vertical sweep. Since all transponders on a DishPro setup are on one polarity, it picks them up twice when it blind scans, hence the doubles. The way to fix this is to set your scan so that it only scans vertical. That way, it only scans one polarity and doesn't do a second sweep to pick up the same channels again.

Now, if you are not using DishPro, this is not an issue because your receiver will blind scan 12200-12700 (instead of 12200-13500) and will pick up only "horizontal" channels on one sweep and only "vertical" channels on the second. There will not be any duplicates.

So, in a nutshell, here is how you configure your settings:

If using DishPro:
LNB Type (Antenna settings menu) = OCS-DP
Polarization (Blind scan menu) = Vertical

If using Legacy:
LNB Type (Antenna settings menu) = Standard (sometimes called Single)
Polarization (Blind scan menu) = All