Troubleshooting BEC 6600+ Signal Strength!

[texasclaw]

I still get the yellow bars when I check my transponder setup, but the signal appears weaker, with both lines around 50. Normally I get 80+ on the top line. At various times I get tiling and at other times "No Video" or "Poor Signal"

What could cause this and how do I resolve it. I just had a new LNBF put in to stop the tiling.

Help!

[bobkat]

When you put the new LNB on did you make sure the skew was set properly? Did the signal level and quality drop right after the new LNB was installed or did the levels drop off gradually? Could be that the new LNB is not as sensitive as the old one. Other things to check are dish alignment (may have move a bit) or perhaps a tree is growing in the way.

kat

[texasclaw]

kat,

Sorry i posted to the wrong forum.

Where do I put a question like mine? I am new to this.

The signal was strong at first and gradually dropped off. I have been told that the LNNF may be 180 degrees reversed.

Help!

[bobkat]

Looks like the right forum to me. No problem.

What satellite are you pointing at? Having the LNBF reversed at 180 degrees will be just as good as have it set properly. Unless you are talking about the reversed polarity LNBs for a torroidal dish. :shock:

kat

[texasclaw]

kat,

I am pointed at AMC7 for Alaska Network Channels and AMC1 for DW-TV(Deutche Welle).

[bobkat]

Originally Posted by texasclaw

kat,

I am pointed at AMC7 for Alaska Network Channels and AMC1 for DW-TV(Deutche Welle).

LOL !! :lol: OK -- you're talking C-Band here... :roll: I guess it is sort of in the wrong forum now -- I'll move it.

So, forget what I just said in the other posts. The likely cause is a faulty polarizer motor; I suggest you replace it. Unless you have a fixed LNBF. Not likely if you have a moveable dish, which you must to get AMC 7 and AMC 1.

Where's spyder when we need him... :?: He's up on C-Band stuff.

kat

[texasclaw]

I was moved to this forum by kat.

I have a Motorola i450 analog receiver and a BEC 6600+ Digital Receiver. I am having problems with the Digital channels tiling and disapppearing. kat mentioned something about a bad polarizer motor. Did he mean in the receiver or on the dish. I do have an LNBF (new) that is supposed to bring in Digital really good.

What do I need to tell my Dish repair person to do. He does not have much experience with FTA or Digital Receivers and we don't have anyone else here in town that I can trust to come out (there is only one other C-
Band person in town and he dislikes that I buy my own parts for 50% less).

Help!

[bobkat]

Originally Posted by texasclaw

kat mentioned something about a bad polarizer motor. Did he mean in the receiver or on the dish. I do have an LNBF (new) that is supposed to bring in Digital really good.

What do I need to tell my Dish repair person to do. He does not have much experience with FTA or Digital Receivers and we don't have anyone else here in town that I can trust to come out (there is only one other C-
Band person in town and he dislikes that I buy my own parts for 50% less).

Help!

The polarizer motor is on the dish - specifically it is attached to the feedhorn assembly along with the LNB. If your C-Band repair person does not have much experience, as you say, then you might have difficulty explaining it to him. Polarizer motors are cheap - around $45.00 -- so for you that would be $22.50... :wink:

Tell him to bring another polarizer motor - he should know what that is.


Good Luck.

kat

[texasclaw]

Kat,

I didn't mean that I can get parts for 50% of what they normally cost, however the person I was talking about wanted to charge me more than twice what I could get an actuator arm for. He wanted 180 dollars(He says he has to mark up parts in order to make money :roll: ) and I found one online for 85 dollars.

I have a DMS ;International Model: ASC421, 13 degree K C-Band LNBF. My repair person understands C-Band very well. I was thinking that you ment something concerning the Digital Receiver.

What I also need to know is why I still get clear pictures on all of my regular analog C-Band channels and just problems with my Digital channels?

Help!

[bobkat]

Your C-Band is clear because the C-Band LNB is functioning properly. Which receiver is controlling your polarity? The GI or the BEC? I can't remember if the 6600 has polarity control or not.

kat

[texasclaw]

My Motorola i450 controls my polarity. The BEC6600+ is just slaved to it so my wife can get DW TV and I can get UPN Alaska. All the Digital channels are set up according to the analog channel setup. Whenever I can get the satellite clear that the digital channel is on then the FTA channels usually show up.

[bobkat]

Well, if the polarity motor isn't the problem then the only other possibilities are a bad cable or connector or the KU LNB is going bad - although you just replaced it. Your C-Band repair person will be able to fix it because it is definitely a dish problem. The BEC receiver is OK.

kat

Did you try tweaking the dish to improve picture quality. Override the autopeak feature on the 450i.

[texasclaw]

kat,

I don't have a ku LNB.

I will try to tweak the i450, if I can "wrap my brain abound the instructions in the book" .

Thanks for the help!

[spyder]

Evening guys, I've been so busy lately I've gotten behind on the forums.

Is this the C lnbf you have? http://www.dmsiusa.com/c-band_lnbf.htm

My first question is: Do you have a DC blocked coax splitter between the 450i and the BEC? With the power passing only to the 450i?

My second question is: on the 450i are you able to get both horizontal and vertical analog channels? I'll need to check back with my GI #50i documents but I don't think those units have the voltage output capability needed to control the lnbf type units. But I could be wrong about this.

Do you use this unit (450i) for viewing your normal satellite channels?

Also the Alaska mux on AMC7 has been very finicky lately. Many have reported loosing the abilty to receive them at all. Not sure what has changed, but my reception is marginal at best even with my setup.

Maybe as an experiment swap them around try and let the BEC control the polarity and use the 450i as a positioner unit. (the DC blocked side would then go to the 450i)

But however, my main concern is the lnbf. One thing I noticed is that lnbf has a stability rating of +/- 1.5 mhz, which is not very stable, especially for digital. The lower the symbol rate for the digital carrier the worst the reception is going to be. I recomend a stabilty of +/- 500 khz or lower for the best digital reception, but in a pinch up to +/- 1 mhz can be acceptable.

[bobkat]

There you go, texasclaw... :wink:

I told you spyder would come to the rescue.

Thanks spyder :P

kat

PS: I believe the GI 450i does control polarity switching via voltage; I seem to remember the Innovation series doing this -- I know the 650i does for sure.

[texasclaw]

spyder,

Yes this is the C LNBF I have. I was told that this is one of the best LNBF's for Digital reception.

l. Don't know what a DC blocked coax splitter is(please explain what it is and where do I install it(if this will help my reception), however the coax from my Sat big dish is connected to the BEC LBN In and the Sat polarizer & Actuator to the 450i. The BEC Output to the VCR Line In2.

2. Yes I am able to get both H and V analog channels.

Yes I use the 450i to view my normal satellite channels

I loose the Alaska channels sometimes(I use them because I can't find a C-Band (I don't have ku) UPN analog channel nor a UPN digital closer to Texarkana, TX), but most of the time they come in very clear. However the same thing happens to my wife's DW-TV on AMC1 as well.

Will try the experiment once I get splitter, if I really need one.

Why does the info on the "Features"(on the link you sent) for the LNBF state that it is "Special for Digital C-Band Satellite Reception"? What kind of LNBF would you recommend?

kat,

My C-Band repair person said that the 450i does switch polarity with voltage(I used to have a switch with my old Uniden 4400, but he took it off when he set up the 450i)

[spyder]

Yes , I think you and Bobkat were correct about the 450i doing voltage switching. Tinkering with so many receivers I forget which ones have coffey makers and which ones have toaster ovens built in. :lol: :lol:

Firstly, if your not familiar with this site, it has a wealth of information and fine tuning tips. I've used the resources here quite a bit. : http://www.geo-orbit.org/sizepgs/tuningp2.html

I would first go through and do a little fine tune checkup to make sure the dish is alligned as best it can be. Digital requires much more accuracy in dish allignment that analog.

A DC block splitter is usually used when splitting the coax coming from the dish (lnb) to the receiver in order to connect to a second receiver. The reason for this is that if both receivers are trying to send a voltage signal to the lnb at the same time you can end up overpowering and frying the lnb. Sometimes turning the "lnb power" setting on the fta receiver to off will do the trick, but I like to be on the safe side and use a power block splitter.

I'm not really saying that lnb is a bad lnb, just that it's not the highest of stability. I've seen "great digital unit" and "perfect for digital reception" etc etc on so many advertised lnbs that I always just laugh. For the average 4DTV didgital signal they are usually fine. But DVB/FTA digital is sometimes a totally different animal. The symbol rates are sometimes very low in comparison to 4DTV signals, and that's where the stabilty comes into play. EG: Most 4DTV signals are in the 20000 symbol rate range. I've seen many dvb signals be as low as 2000, many in the area of 4000-5000. When the lnb has a +/- of 1.5mhz, with a 2000 SR carrier that 1.5 will take it completely out of reception if the lnb indeed drifts the full 1.5 off frequency.

The best option is always the more expensive option. I like to use the corotor type feedhorn with seperate C and KU lnbs with mechanical polorizor units. And as stated earlier the lower the stability rating of the lnbs the better. I usually don't recomend any lower tan +/- 750 for good digital reception. I use the +/- 250 models myself. I like the Norsat brand personally.

Check the link in my sig below, under "dvb sat setup" you'll see the corotor type feed that I use.