NASA on AMC-7 @ 137W and polarity

[dougbrown]

I have been trying to pick up the NASA feeds on 137W with little success. I am able to get the 360 North feed on the same bird consistently. One thing I've noticed is that the 360 feed will show up on both H & V polarities. At first I thought my corotor was bad, so I replaced it but the same thing happens. On other sats I am able to pick up both polarities, for example 16 and 17 on analog on G4. Any Ideas as to what might be going on here?

 

[Mr Tony]

NASA at 137 is a bugger to get....I think for most folks they (NASA) want you to use 72W...maybe 137 is better on the west coast?

I can lock 360North with 60 quality on the Pansat 1500 and the 6 footer but on NASA I get 15 max...on 72W I can get NASA at 45 quality

 

[eurosport]

I use 72w for Nasa 'cause 137w has some tree blockage for the 10 footer.

 

[dougbrown]

Eurosport, I have just the opposite problem as you, for me 72w is in the trees

 

[tvropro]

I get Nasa on 137 with no problem just like 72w. For you guys with smaller dishes you have to remember that when you get lower in the arc even if your fully illuminated you have ground noise (K kelvin) to deal with. That combined with the smaller dish that has a higher noise temperature to start with weakens your carrier to noise ratio. For the best performance you want your dishes noise temp lower than the ground noise. 12 footers have some good numbers at low look angles, at 137w Im a 20.7 degree elevation. I took this information into consideration back in the day when I upgraded my dish from a 10 foot to 12 foot. There's a whole science involved when you do your link budget for what you want to receive well.

This month my 12 footer celebrates it's 20'th birthday and still going strong.

 

[i4tas]

I get both 72 and 137 in so wisconsin. The alaska mux (360) is only seen on H for me on a 7.5 ft dish, the nasa only on V. Check the skew, sounds like it is off by 45 to 15 degrees

 

[rainmaker]

No problems here getting both on a 8.5 ft dish 72 is a little stronger but get good lock on 137 at 50 quality.

 

[starman345]

I get both 72 and 137 pretty strong here but 137 is deep "in the weeds" for elevation. It looks like the face of the dish is just about perpendicular to the ground.

 

[eurosport]

Eurosport, I have just the opposite problem as you, for me 72w is in the trees

That must be why it's on both ends of the arc...nobody misses out!

 

[Mr Tony]

I get both 72 and 137 in so wisconsin. The alaska mux (360) is only seen on verticle for me on a 7.5 ft dish. Check the skew, sounds like it is off by 45 to 15 degrees

interesting. I can't get the mux on V...only on H

 

[dougbrown]

Well, I was successful, finally. It was a polarity problem. By adjusting the polarity on 360 North until the signal died and then scanning for Nasa I was able to pick up a weak signal. Further fine tuning has be hard to say the least. This is most likely due to several factors, one the bird is very low on the western horizon for me so low in fact that the 4 foot high chain link fence bordering my property is blocking about half the dish, and then there was a bus load of weeds growing through the fence (these have since been trimmed). I'm getting a fair signal now but still experience both audio and video breakups.