Please Help horizontal lines in picture

[Gray1]

I could really use some help. I have a Uniden 4600 and a Orbitron C-10 dish.
I am trying to get it up and running but having a terrible time. I have thin horizontal lines running through my picture. I have tried to peak the dish and the
satellite quality signal is 100% with signal strength at 8 out of 10 dots on the
signal bar. I still have these thin horizontal bars.

http://www.brick.net/~pcguy/Allen/1.jpg


They are the thin bars around the head of the guy sitting on the right hand of the
screen. Maybe some of you got some ideas. The guy at NPS told me it was the LNB
but I dont know. I have ran another RG6 cable from dish to reciever. That didnt help. I have a couple of trees, but i would think that the signal strength was suffecient not to have bars. I'm outta ideas, and the guy that installed it has long gone out of business.

So any suggestions or ideas would be greatly appreciated.
Thanks for your time and consideration.

Gray1

 

[sksatellite]

Its call hum bars, uses with the grounding problem as ground loops.
Check all connection and see if there bad connection or wiring.
Inadequate system voltage can have the same effect and cause hum bars by not providing enough power to generate the necessary signal to adequately power to receiver. this happened by under size wire is use on a long run to the LNB or the wire could be bend somewhere, so the cumulative cable resistance causes unacceptably large voltage drops.

 

[Greg Mueller]

Unplug everything from the 110v plug-in that has you receiver plugged into it. Sometime those fluorescent lights can cause problems

 

[Harry77]

What exactly do the "bars" look like?

 

[Gray1]

I have unplugged everything at the wall socket but tv and satellite. I'm pretty sure
its not interference. The wire size is the standard setup that has worked correctly for years. How do I check the voltage at the LNB? I have a DVM. Could a bad LNB cause these "hum bars"?

Thanks for the help

Gray1

 

[gizzer777]

could also be....

I have unplugged everything at the wall socket but tv and satellite. I'm pretty sure
its not interference. The wire size is the standard setup that has worked correctly for years. How do I check the voltage at the LNB? I have a DVM. Could a bad LNB cause these "hum bars"?

Thanks for the help

Gray1

Is your equipment plugged into an AC line conditioner? Sometimes "noise-lines" can be from dirty power.

Have you tried hooking up to another TV...the TV could also have a problem.

long shot but worth a try!
jeff

 

[Gray1]

well i checked the voltage at the reciever and the LNB it is 18.16 dc volts at both places. It doesnt change when i switch channels. I dont know if that is normal or not.

Gray1

 

[iammike]

Just a thought, but is there anything else plugged in on that circuit? Maybe it isn't anything next to the receiver or TV, but something on the other side of the room.

Mike

 

[Gray1]

im gonna look at that. I tried to get a ac power conditioner today but couldnt find one in my rural area. Im gonna look more into that interference thing. maybe turn off a few circuit breakers and see what happens. I will get back with you.

thanks for the help guys

 

[Gray1]

Need Help From C-Band Expert

I still cant get this issue resolved, maybe someone here can help or advise.

I have a Uniden 4600, Orbitron C-10, Chaparral Corotor,and Norsatt LNB.

My picture is kinda fuzzy, with some lines. It is watchable but its not right.
I have replaced coax, replaced feedhorn. Peaked the dish several times. I am confident it is not Electrcal interference.

My signal strength (G5) is 80% with 100% signal quality. But the picture is still
not the way it should be. How can this be possible?

I bought the Norsatt used off E-bay. They said it worked..I have not replaced the LNB (its the only one I have). Could this be a bad LNB? There are no sparkles on the screen.

Could it be some other hardware failure? This stuff is all old. I'm just not sure what to do.

Thanks all

Allen

 

[Hermitman]

Sounds like it could be an overmodulation problem. Have you tried a different TV like someone else suggested? Have you tried changing the receiver output from channel 3 to channel 4 or vice versa? If it has a composite video output that's not connected, try hooking that up and see if the picture improves. On some older Unidens, there was an input gain adjustment screw on the back panel. If you have one, maybe it's adjusted too high. Also, some Unidens had the TI on/off switch on the back panel. If so, change the switch position and see if that helps. Have you tried adjusting the L.O. frequency adjustment on the receiver? Maybe it needs to be matched to the LNB if the LNB is old and started to drift off-frequency. Good luck and have fun.

 

[Gray1]

Have tried two tvs..Channels 3 and 4 and with individual cables (L1). Have tried TI filters on and off.
What is the LO frequency adjustment. Could you explain that a little.

Thanks for your response

allen

 

[Hermitman]

Sometimes older LNBs will drift off frequency maybe by 5 or 10 khz. Your receiver doesn't know this and tries to process the off-frequency signal causing a distorted picture. Many receivers have an option located in a sub-menu that allows you to compensate for this off-frequency signal and clear up the picture. I'm not sure about your receiver but look in the video options menu for something like "center freq adjustment" or "video fine tuning". You should see where the receiver allows you to adjust the frequency approximately plus or minus 15 khz in .25 khz blocks or thereabouts. Hope this helps. Good luck and have fun.

 

[whatchel1]

How old is the unit

How old is the Uniden 4600? could be the caps in the unit are starting to go south on U.

 

[Gray1]

I have no idea how old the unit is.. I bought it used off ebay. I have not been able to get this system "right". It could be the unit. It could be my used LNB. The problem is i dont know which way to jump. There is not a lot on analog C band anymore so I dont want to spend a lot of money on it.

By the way what do i do for overmodulation. The coax run is short maybe 35 feet.

Thanks
allen

 

[Hermitman]

I'll give this one last shot. The overmodulation can be reduced by adjusting the input level from the LNB with the input adjustment screw (if you have one). I'm assuming your picture distortion occurs on all channels and all satellites. If your distortion is most noticeable when red colors are on the screen, that indicates your IF bandwidth is too narrow. Some older receivers allow you to adjust your IF bandwidth. Check your menus for something like an IF bandwidth adjustment of 15, 27 and 32 mhz. 15 mhz is too narrow for normal viewing. 27 is the normal setting. If you can, increase the bandwidth and see if that betters the picture. Also, have you checked to see if you have any high-powered transmitters, like TV or radio towers, in your immediate area? Good luck and have fun.

 

[somery]

You can get a brand new chaparral lnb for 20 dollars here. its standard 1mhz stability. Your norsat probably had like 500khz but maybe it is going bad/getting old. Never heard of interference other than sparkles tho.
http://www.impaktproducts.com/home.php?cat=272 hope i can say this here? Do the sponsors own the forum?

 

[bryansr]

I have had this horizontal line problem caused by the polarotor servo motor. After they are older they just start running and won't stop after changing channels. To check this unplug the wires going to the servo motor and the lines will go away. Replace the servo motor and make sure that it is set in 90 degree so it don't turn too far and add excessive wear.

BryanSR