Polarity & Scanning in V & H Transponders on C and KU Band Question

[jsattv]

I recently had a 2 hour power failure in our area resulting in a complete loss of all Channels & Satellites on my Viewsat Sat Receiver on my 12 Footer Mesh Dish. I had a lot of older not working channels & about 15 Sats and many channels which had been changed and were no longer coming in, so a rescan was needed anyways.

In rescanning via a Blind Scan I used to always get duplicate channels when the Blind Scan of a Satellite goes through the V and H Transponders scan process. I thought I had it resolved when on redoing 97.0W - Galaxy 19 on KU Band I got about 249 Channels and no duplicates by switching over to V on my Uniden 9900 (which is slaved to my Viewsat FTA Rx via a V Box III) for the V scanning Tp's then switching back on the 9900 to H when the H Transponder channels were scanning in.

Here is the Confusing Part re Polarity:
But yesterday when I scanned in 95.0W- Galaxy 3C on C Band and even though all the Tp's are listed as V Tp's I could NOT get any channels to scan in until I switched the 9900 over to H Polarity on the front of the 9900? It also happened on Sat 101.0W which has all V Tp's. I am totally confused? What am I missing here re V and H Tp's or Polarity?? That is, don't you have to be on V Polarity for the V Tp's and on H Polarity for the H Tp's? Any comments / replies to end this confusion would be greatly appreciated.

 

[FaT Air]

I bet the Uniden is running your polarity servo. If so - You'll have to scan one polarity at a time.
Select polarity with Uniden, scan that polarity, Switch polarity with the Uniden, scan that polarity.

 

[jsattv]

I bet the Uniden is running your polarity servo. If so - You'll have to scan one polarity at a time.
Select polarity with Uniden, scan that polarity, Switch polarity with the Uniden, scan that polarity.

Thanks a lot for the reply Fat Air. Yes the Uniden 9900 is running the Polarity servo and I do switch it over via the Uniden Remote from V to H Polarity. The Blind scan on the Viewsat usually first goes thru all the H Polarity Channels, then switches over to the V Polarity Channels. There is also a signal strength meter on the Viewsat for S and Q levels. What I do is switch the Uniden to V polarity for the V Scan, and then switch the Uniden over to H polarity for the H scan of channels. I guess my point is I am trying to understand how there can be Signalling Levels showing up on H scan when V Polarity only channels are being scanned?

 

[FaT Air]

Good question, to paraphrase
[how can H polarity channels show up when only V Polarity is being scanned?]
My guess is that it's to do with the servo/ feed.
Foreign matter in the feed horn? The dielectric plate is removed? ( only needed for circular polarity.) Is the servo rotating the probe a full 90 degrees? Is it peaked on each polarity? I'm leaning towards servo wear/failure, or servo-polarity programming.

 

[delta_charlie]

Thanks a lot for the reply Fat Air. Yes the Uniden 9900 is running the Polarity servo and I do switch it over via the Uniden Remote from V to H Polarity. The Blind scan on the Viewsat usually first goes thru all the H Polarity Channels, then switches over to the V Polarity Channels. There is also a signal strength meter on the Viewsat for S and Q levels. What I do is switch the Uniden to V polarity for the V Scan, and then switch the Uniden over to H polarity for the H scan of channels. I guess my point is I am trying to understand how there can be Signalling Levels showing up on H scan when V Polarity only channels are being scanned?

Hi, I think what's going on is the Viewsat uses voltage change to the LNB to signal the vertical or horizontal polarity and assumes the polarity changed when it changed the voltage. When you use an analogue receiver to control the servo motor the polarity will not change with the voltage change so what ends up happing is the DVB receiver thinks it is scanning one polarity and has no idea the polarity did not move so it scans the channels on the wrong polarity.

To fix this simply blind scan one polarity (the same as what is set on the analogue receiver) at a time.

Hope this helps, DC

 

[jsattv]

Hi, I think what's going on is the Viewsat uses voltage change to the LNB to signal the vertical or horizontal polarity and assumes the polarity changed when it changed the voltage. When you use an analogue receiver to control the servo motor the polarity will not change with the voltage change so what ends up happing is the DVB receiver thinks it is scanning one polarity and has no idea the polarity did not move so it scans the channels on the wrong polarity.

To fix this simply blind scan one polarity (the same as what is set on the analogue receiver) at a time.

Hope this helps, DC

Thanks for the comments delta_charlie. I am scanning in one polarity at a time & you are likely correct re the Viewsat. It starts with a H BlindScan then it goes to a V BlindScan. When this is happening I do switch the Uniden 9900 to the V or H Polarity that is being scanned in, and so far it is preventing duplicate channels from being rescanned in.

To more explain the problem / confusion, - yesterday when I scanned in all 70 channels on Galaxy 17 - 91.0W on KU Band, - when the V Polarity was being scanned in I switched the Uniden 9900 over to V Polarity but here is what was coming in:
Searching V Freq S/R Pol
Freq 3560 3921 7250 H

The question is if V is being Searched or scanned in then how the heck can H Polarity show up? For Satellites such as 97.0W when V was being Searched the Pol also showed up as V, and the same thing happened with H Search and Freq Pol. But as you suggest maybe the Viewsat uses Voltage Change when it changes Polarity, but I'm not sure I totally understand this.

 

[B.J.]

Thanks for the comments delta_charlie. I am scanning in one polarity at a time & you are likely correct re the Viewsat. It starts with a H BlindScan then it goes to a V BlindScan. When this is happening I do switch the Uniden 9900 to the V or H Polarity that is being scanned in, and so far it is preventing duplicate channels from being rescanned in.

To more explain the problem / confusion, - yesterday when I scanned in all 70 channels on Galaxy 17 - 91.0W on KU Band, - when the V Polarity was being scanned in I switched the Uniden 9900 over to V Polarity but here is what was coming in:
Searching V Freq S/R Pol
Freq 3560 3921 7250 H

The question is if V is being Searched or scanned in then how the heck can H Polarity show up? For Satellites such as 97.0W when V was being Searched the Pol also showed up as V, and the same thing happened with H Search and Freq Pol. But as you suggest maybe the Viewsat uses Voltage Change when it changes Polarity, but I'm not sure I totally understand this.

I assume that you did NOT delete all transponders before starting your scan. My guess is that your receiver had these wrong transponders in it's transponder list before you started the scan. I'm not familiar with your receiver, but usually these receivers scan for new freqs, and when they find freqs, they add it to the list of freqs it already has for that sat. Then, after it has scanned for freqs it goes through each freq, both the new ones and old ones, looking for channels. So for one thing, if you're trying to do both H and V on one scan, you'll probably have to switch from H to V during the freq scan, then again H to V during the channel search. So if in the past, you had run scans without changing polarity, the odds are that you have duplicate freqs in your list, and even if you are careful to switch now, those transponders will still be there, plus if you aren't changing polarities during the channel search, you'll only pick up channels of the polarity you left it on after the freq search.
If I understand what you're saying, your receiver must not have the option of scanning just H or V separately, which is unusual, and unfortunate, because it really complicates things. You might be best off just living with having duplicates. It's hard to avoid them if your receiver won't scan one polarity at a time.

 

[jsattv]

I assume that you did NOT delete all transponders before starting your scan. My guess is that your receiver had these wrong transponders in it's transponder list before you started the scan. I'm not familiar with your receiver, but usually these receivers scan for new freqs, and when they find freqs, they add it to the list of freqs it already has for that sat. Then, after it has scanned for freqs it goes through each freq, both the new ones and old ones, looking for channels. So for one thing, if you're trying to do both H and V on one scan, you'll probably have to switch from H to V during the freq scan, then again H to V during the channel search. So if in the past, you had run scans without changing polarity, the odds are that you have duplicate freqs in your list, and even if you are careful to switch now, those transponders will still be there, plus if you aren't changing polarities during the channel search, you'll only pick up channels of the polarity you left it on after the freq search.
If I understand what you're saying, your receiver must not have the option of scanning just H or V separately, which is unusual, and unfortunate, because it really complicates things. You might be best off just living with having duplicates. It's hard to avoid them if your receiver won't scan one polarity at a time.

BJ, my Viewsat Receiver does have the capability of scanning in Both H and V Tp's separately. First I look up the most current list of Tp's and insert them in while deleting the old ones. Then I set the Uniden 9900 that my VBox III and Mesh Dish is connected to for the Polarity that the Viewsat is Blind Scanning in. So far have scanned in 19 Satellites, and approx 700 channels. Its amazing how much has changed on some Sats.

But I am considering a new Receiver with HD since I moved up to an HDTV last year, and my Viewsat also does NOT have ac-3 capability. Is AzBox one of the better ones? Is there lots of HD channels out there?

 

[B.J.]

....
But I am considering a new Receiver with HD since I moved up to an HDTV last year, and my Viewsat also does NOT have ac-3 capability. Is AzBox one of the better ones? Is there lots of HD channels out there?

There is no one HD receiver that does it all, and there is no receiver that doesn't have bugs, so which is best kind of depends on a tradeoff between what you want to watch and the bugs in the receiver that get's those things.

I have an Azbox elite, Diamond 9000, and Coolsat 8100 STBs, and add to that several PC based receivers like the Twinhan 1020a, TT3200, Broadlogic 1030, and Genpix Skywalker 1, all of which give me HD capability, however to watch HD via the PC receivers, I need to stream to either the Azbox, a ROKU HD1000, or PopCornHour.
Of the STBs, despite the fact that they have yet to come out with anything but beta software for the receiver, and people have been complaining about the receiver's bugs right and left, it is my favorite receiver, mainly because it is the easiest to manually program in DVB-S2 transponders, and it does 4.2.2 HD. The Azbox does have some limitations, primarily that it can't record or play streams of high bitrate HD. I have hopes that someday this will be fixed, but have been waiting over a year, and no fix yet, so it may never come. If it could play high bitrate streams, that would be great, because it would replace both my Roku and PopcornHour.
The Azbox Elite doesn't have blind scan, but people have been reporting all sorts of bugs with the newer models that do have blind scan. I really believe that 90% of the problems people report are due to the way people are using their receivers, as some people don't seem to have any problems, however it's hard to recommend one of those receivers until the source of the problems is determined.
Anyway, to me, 4.2.2 is important, so Azbox is the only answer, other than getting a much faster computer. If you're not interested in 4.2.2, then one of the other STBs, like Pansat or one of the newer STBs might be a better choice. Personally, I do 90% of my actual sat viewing by streaming from my PC cards, mainly because I tend to record things for later viewing, or delay live viewing, neither of which I can do with an STB until Azbox fixes their bitrate limit.


Anyway, Azbox is the most capable receiver out there, but be prepared for confusing behavior or bugs.

 

[jsattv]

There is no one HD receiver that does it all, and there is no receiver that doesn't have bugs, so which is best kind of depends on a tradeoff between what you want to watch and the bugs in the receiver that get's those things.

I have an Azbox elite, Diamond 9000, and Coolsat 8100 STBs, and add to that several PC based receivers like the Twinhan 1020a, TT3200, Broadlogic 1030, and Genpix Skywalker 1, all of which give me HD capability, however to watch HD via the PC receivers, I need to stream to either the Azbox, a ROKU HD1000, or PopCornHour.
Of the STBs, despite the fact that they have yet to come out with anything but beta software for the receiver, and people have been complaining about the receiver's bugs right and left, it is my favorite receiver, mainly because it is the easiest to manually program in DVB-S2 transponders, and it does 4.2.2 HD. The Azbox does have some limitations, primarily that it can't record or play streams of high bitrate HD. I have hopes that someday this will be fixed, but have been waiting over a year, and no fix yet, so it may never come. If it could play high bitrate streams, that would be great, because it would replace both my Roku and PopcornHour.
The Azbox Elite doesn't have blind scan, but people have been reporting all sorts of bugs with the newer models that do have blind scan. I really believe that 90% of the problems people report are due to the way people are using their receivers, as some people don't seem to have any problems, however it's hard to recommend one of those receivers until the source of the problems is determined.
Anyway, to me, 4.2.2 is important, so Azbox is the only answer, other than getting a much faster computer. If you're not interested in 4.2.2, then one of the other STBs, like Pansat or one of the newer STBs might be a better choice. Personally, I do 90% of my actual sat viewing by streaming from my PC cards, mainly because I tend to record things for later viewing, or delay live viewing, neither of which I can do with an STB until Azbox fixes their bitrate limit.


Anyway, Azbox is the most capable receiver out there, but be prepared for confusing behavior or bugs.

Thanks for the very detailed response B.J. Wow what an impressive array of Receivers you have. One other question, if you don't have Blindscan with your Azbox Elite then how the heck can you scan in the Satellite Channels? Also as you noted and from reading at at Ricks Sat there have been problems with the External Power Supply on the newest Azbox with Blindscan?

 

[B.J.]

Thanks for the very detailed response B.J. Wow what an impressive array of Receivers you have. One other question, if you don't have Blindscan with your Azbox Elite then how the heck can you scan in the Satellite Channels? Also as you noted and from reading at at Ricks Sat there have been problems with the External Power Supply on the newest Azbox with Blindscan?

Re array of receivers, not really that many. Many people here have two or three times that many, plus the above are only the ones that do HD.
Re finding signals without blind scan, I do have a couple blind scan receivers, but they only do DVB-S. To find DVB-S2 signals (and other modes like DCII, DSS or turbo FEC, etc), I use my Broadlogic 1030 receiver with a program called BLSCAN, which was written by a fellow named Hans ? (can't spell his last name, but he wrote DVBAPPS). It will do a SLOW scan of the whole sat, generating a text file, which I load into a VB program I wrote, which will generate a spectrum plot of the sat band, and it will allow you to determine the frequency, and get a rough approximation of the SR. Then I tune my analog receiver to each frequency and use a shortwave receiver to tell me the exact SR of the signal. I then manually enter the S2 signals into the Azbox, and via trial and error find the FEC/pilot parameters.

A bit time consuming. Usually takes me about 8 minutes per polarity to do the scans, then another 4-5 minnutes to find the SR of each new signal I find.
However most transponders I just find on Lyngsat and other lists. An S2 blind scan capability would be a lot easier, but I'd still do the above, because blind scan receivers generally miss a lot of transponders, plus not all the signals are DVB or DVB-S2.

 

[jsattv]

Re array of receivers, not really that many. Many people here have two or three times that many, plus the above are only the ones that do HD.
Re finding signals without blind scan, I do have a couple blind scan receivers, but they only do DVB-S. To find DVB-S2 signals (and other modes like DCII, DSS or turbo FEC, etc), I use my Broadlogic 1030 receiver with a program called BLSCAN, which was written by a fellow named Hans ? (can't spell his last name, but he wrote DVBAPPS). It will do a SLOW scan of the whole sat, generating a text file, which I load into a VB program I wrote, which will generate a spectrum plot of the sat band, and it will allow you to determine the frequency, and get a rough approximation of the SR. Then I tune my analog receiver to each frequency and use a shortwave receiver to tell me the exact SR of the signal. I then manually enter the S2 signals into the Azbox, and via trial and error find the FEC/pilot parameters.

A bit time consuming. Usually takes me about 8 minutes per polarity to do the scans, then another 4-5 minnutes to find the SR of each new signal I find.
However most transponders I just find on Lyngsat and other lists. An S2 blind scan capability would be a lot easier, but I'd still do the above, because blind scan receivers generally miss a lot of transponders, plus not all the signals are DVB or DVB-S2.

BJ thanks for the reply, scanning in your Satellite Tp's sounds pretty complicated. For now I think I'll look for an HD Rx with Blindscan. So is the the Azbox Ultra HD the one of choice with all the other goodies? Or what would I be missing? An external power supply seems like something I would not miss anyways.

 

[B.J.]

I don't know much about the Ultra. Perhaps someone who owns one might help. All I know is that it has a USB port up front, which is nice, however it has a non-removable single tuner, which is different from the other models.