Transponder strength

[dieselclacker]

I am still having problems with my Movin Vu stationary Winegard dishs ability to lock onto the Directv sattelite.
It is very inconsistant, and when it does lock on to the signal, I get no reception on the TV. Upon checking the signal strength from the individual transponders from the Directv sattelite, the odd numbered transponders show zero for strength, while the even numbered transpondered show normal strength. This doesn't happen every time I try to use the system, but is becomming more frequent. Also may or may not be related to the problem, sometimes after seeking out and aquiring the sattelite signal, the program guide from Directv will not load into my receiver. I have been able to fiddle around with the setup menu, and change the type dish from Round to Oval, or vice versa, and this sometimes works to get the guide to load. Without the guide, I cannot receive any picture on the TV. The system has just started having these problem this past year.
Could the automatic aiming of my dish be at fault, or maybe the receiver? Or both?
Any help resoloving this situation would be greatly appreciated.
On edit: I should add that the motorhome receiver when connected to my home Sattelite dish works with no problems.


Dieselclacker

[wa8yxm]

That one is easy to fix Diselclacker.. (At least most of the time)

There are basically 2 possible problems and one of them has two solutions

Most likely problem: Receiver is not communicating properly with antenna.

Solution.. The Big Red Buttton (RESET BUTTON) it is behind a door on the front of your receiver.

Solution 2: Wade through the menus to RESET and then when ask hit the dash key (Yes there is a dash key) 3 times on the remote.

I very strongly suspect that will fix it..



Problem #2. Is a bad LNB on the antenna.. That is a bit harder to fix since it takes a trip to the store.

Let me know if you need the full technicial explanation but the short version is this.. The LNB has two different antennas. Sat TV signals are transmitted with what is called circular polarization. This means the signal "Screws" into the antenna like a bolt into a nut.. As you may know, epically if you drove vintage Chrysler products, there are Right and Left handed nuts and bolts.

The Satellite transmits two signals on the same frequency, ONe clockwise (Right hand) and one Counter Clockwise (left hand) You will see these on your receiver as Even and Odd transponders.

The Receiver sends a signal to the LNB "Send me the RIGHT HAND signals" (or send me the left hand signals) and then it picks the one it wants.

NOTE: Many folks think the DISH-500 is a DUAL LNB, (It is but it is properly called a TWIN) SIngle and Dual, when applied to LNB's refer to the DISH-300 or the regular DirecTV, A Single can send EITHER odd or even transponders (Left or Right polarization) but not both, A DUAL can send one down one cable and either the same, or the other, down another cable (DUAL means DUAL output)

I will also mention that how the two systems (Dish and Direc) select odd and even is different.. Dish sends either 13 or 18 volts down the cable to the LNB

Dish uses "Stacking" or Frequency domain multiplxing (That is even is converteed to one frequency band..> Odd to another)

Dishnetwork receivers are very intelegent and can work with a DirecTV antenna (Pointed at a DIsh Satellite) the reverse may not be true.

[Bill Adams]

There is another possibility that I recent became aware of when working with some King Dome techs. If your antenna locks onto a satellite but you only receive the even numbered transponders it is most likely that you are actually locked onto the 71.5 satellite and not the DirecTV 101. You can tell if you take the dome off and compare the compass heading where 101 is located with the direction the antenna is actually pointing. It it's off by about 30 degrees then you are pointing at 71.5.
You should also have the receiver setup for a round 18" dish (single LNB) for DirecTV.

[Gary RVRoamer]

I used to have that problem all the time with my old KLH SF dome. It was locking on the wrong satellite, as Bill explained. That satellite looks and sort-of acts like the right one, but doesn't have the right stuff. I finally swapped domes for one that was smart enough to tell the difference.

It may be that some new internal programming will help your MovenVu get the right signal. Don't know enough about that model to say.

[dieselclacker]

Thanks Gary and Bill, I believe you may be correct that somehow it is locking onto the wrong satellite. If it ever stops raining here long enough, I will pull the top of the dome and check the compass setting against the direction the dish is pointing. I know nothing about how to get the thing to select the right sattelite. Maybe recycling the dip switches will help.
Thanks for the advice.

Dieselclacker

[SCVJeff]

Quote:

Originally Posted by wa8yxm Let me know if you need the full technicial explanation but the short version is this.. The LNB has two different antennas. Sat TV signals are transmitted with what is called circular polarization. This means the signal "Screws" into the antenna like a bolt into a nut.. As you may know, epically if you drove vintage Chrysler products, there are Right and Left handed nuts and bolts. The Satellite transmits two signals on the same frequency, ONe clockwise (Right hand) and one Counter Clockwise (left hand) You will see these on your receiver as Even and Odd transponders. The Receiver sends a signal to the LNB "Send me the RIGHT HAND signals" (or send me the left hand signals) and then it picks the one it wants. .

Slow down there cowboy...! H & V, or RC/ LC transponders are NOT on the same frequency. One frequency per polarity, per satellite.. Odd & Even transponders alternate RC-LC-RC, etc. all the way up the band. There is no set protocol as to odd-even vs. polarity, it is actually aligned that if channel 1 of satellite A is LC, then channel 1 of the adjacent satellite is RC. This is true almost anywhere across the arc, and especially on C-Band where the beamwidth is much wider on the ground.

It is also done to gain adjacent channel interference rejection within the same satellite . IN GENERAL, there is a 15db cross-pole isolation between the 2 polarities, and that really helps the receiver find the proper channel and stay there without the AFC yanking it 20MHz off, but in no way is cross-pole isolation of any antenna good enough to expect to use the same frequency on a different polarity.

[beaverjim]

scvjeff, what did you say jim

[LindaH]

Quote:

Originally Posted by Bill Adams You should also have the receiver setup for a round 18" dish (single LNB) for DirecTV.

Bill, we also have the Winegard Movin' View dome (MV3500A) and are DirecTV customers. Our Movin' View instructions say:

DirecTV must be set to the "two" satellite, oval dish setting.

That's how we have ours set up and have had no problem with it since we picked up our RV in January 2007.

[Bill Adams]

Quote:

Originally Posted by LindaH Bill, we also have the Winegard Movin' View dome (MV3500A) and are DirecTV customers. Our Movin' View instructions say: DirecTV must be set to the "two" satellite, oval dish setting. That's how we have ours set up and have had no problem with it since we picked up our RV in January 2007.

That setting was for the setup when DirecTV was using multiple KU band satellites at 101, 110 and 119. The Movin' Vu could automatically switch between 101 and 119. Today that's simply unnecessary so the round dish setting would be correct but that does not make your current setting incorrect if you are not having any problems.

[SCVJeff]

Quote:

Originally Posted by beaverjim scvjeff, what did you say jim

I said his statement is wrong.