Why is is PBS on AMC3 weak?

[laseradam]

Why is PBS so weak on AMC3? The Bloomberg network has a strength of about 75 while PBS is around 20. For the last two days it is to weak to pick up. I am using an Aspen eagle gold C/KU with a 6 foot dish. I just got it working this week. I also receive 3ABN with a 1 meter dish. Would I be better off getting another 1 meter dish for PBS? I kind of like the idea of being able to to pick up both the DVB C and KU stations on AMC3. And I do have both C and KU working on AMC3 just with a low signal strength.

I have installed MANY KU systems for friends to watch 3ABN on AMC4 but I dont have any experience with KU on a big dish. Any advice?

 

[Mr Tony]

welcome

3ABN is (no pun intended) UNGODLY strong. I just picked it up the other day on a Phase II DirecTV dish (65 quality)

PBS & Montana PBS I get at about a 50 quality with a 30" dish. Best I ever got was when I had a 36" dish at AMC3 and that was 65 or so (the 36" has been parked at G10)

Is the dish mesh or solid? if its mesh and you can slip a pencil in the hole, then KU won't work real good for it.

 

[Diamond Jim]

Are you talking about the regular PBS stations or PBS HD? I get the Montana PBS and the others nice and strong on the 8 footer. About 2 weeks ago I lost PBS HD for a couple of days, very weak signal. It has came back with a decent signal, but I have to bump the dish around and work to get it. As for your questiion.....I don't know.

 

[DiscoLoveGrapes]

If it helps, my experience has been that Montana PBS will usually stay a bit more consistent (about 60% for me), while the other PBS feeds vary from 74% on an exceptional day to 33% on a bad one.

 

[laseradam]

The mesh on the 6 foot dish is tight. And as I say I get the Bloomberg channel at around 75% and also the patient channels at 70 to 75% I looked at the Montana PBS today before work and was getting a signal of around 20%. Could someone check and compare the signal strength of Montana PBS and Bloomberg and the patient channels? Could the difference in wavelengths between Bloomberg and the PBS channels make a difference because of the mesh dish?

 

[Mr Tony]

something might be off because Bloomberg & Patient channel on my 30" are almost at 99 quality. What receiver do you have?

 

[laseradam]

I have the Fortec lifetime classic NA. I would do some repointing of the big dish but the forcast is rain until next week here in Ohio. My 6 foot dish is a fixed mount.

 

[laseradam]

Iceberg what LNB and 30 inch dish specs do you have? Do you think it would be worth it to sell the Aspan Eagle gold c/KU lnb and use the money toward another 30 inch dish? It seems the the 6 foot dish should do better.

 

[Mr Tony]

I use a Winegard 30" (2076 is model number) and a Invacom Quad (QPH-031). I've used an Extreme LNB and thats worked just fine too.

The 6 footer should work better but I know some satellites you may have to "rock" (move E or W) to get optimum KU signal.

 

[Stefan]

It seems the the 6 foot dish should do better.
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There are a few reasons why a large dish like this may not perform as well as a smaller dish on Ku band but 99% of the time it's an issue of improper alignment. If the dish was aligned on C band, even though it appears to aligned pretty good on C it could still be way off and this will show up on Ku. One reason for this is the beamwidth of the dish will be much wider on C band, especially considering the fact that it's a 6' dish which is technically undersized for C band anyway. This means the dish will pick up C band signals from a satellite even when it's not that precisely aimed at the satellite. Also feedhorn alignment, correct focal point adjustment and scaler ring adjustment will be much more critical on Ku. So, while it's possible you dish itself may not be very good for Ku because it's either warped a bit or it's surface isn't accurate enough, the most likely problem is alignment.