Ku Band Question

[hoot550]

I am somewhat of a BUD newbie, but it's been my dream for a long time to be able to get into it. I have recently acquired a 10ft Winegard dish and have got it set up and working. I've got all of the C-band sats programmed in. I also have a FTA receiver slaved on the system and have enjoyed scanning out all of the FTA signals on C-band.

After endless tweaking, I'm fairly confident that my arc is tracking correctly. I have excellent signal east to west and at the top of the arc. (Thanks to geo-orbit.org)

Then I started trying to get Ku working and there went the free time. Everything I read suggested starting with C-band and now I see why. I am able to get a very slight Ku analog signal on my receiver on AMC15 (105 deg) and Echostar9 (121deg). It's just a pattern for Echostar scheduling or something. When I try to use the signal meter on the FTA receiver, it's maybe 6-13% max on any sats. I have checked and measured the centering of the feedhorn, adjusted the focal depth and checked the dish for warping. It's in great shape and has very fine mesh.

Today I went out with a signal meter I purchased from Sadoun and got a decent signal as I adjusted the feedhorn slightly to find the sweet spot, thinking the f/d was off a hair. I go back inside, thinking I have finally got it fixed, and nothing on analog or digital. Repeat this process a dozen times or more. (At 101 deg my signal meter goes off the chart on the Ku side, but there's nothing on FTA receiver. Is this Directv maybe???)

What am I missing? My C-band signal is excellent, no sparkles or anything on almost all channels. FTA receiver has a consistent signal of 70-80% on almost every sat. I know c-band is easier, but am I missing something?

Thanks for any help you can give!

 

[truckracer]

It looks like you have your f/d and focal point tuned in, but your not tracking the arc close enough for KU band on a large dish like a 10 footer. KU band on a 10 foot dish has such a tight beamwidth. It has to be near perfect or you will experience what is happening.

Do the elevation test that is described on the geo orbit website. Find your weak ku signal, then slightly adjust dish elevation - NOT declination.

If you increase the elevation and the signal goes up then you need to loosen the entire mount on the pole and slightly turn the dish mount. Then try again.

Repeat until you track the entire arc or the arc of viewable satellites your dish can see.

When you rotate the mount just do it slightly less than 1/8 of an inch at a time.


I also forgot to ask if this is a solid metal dish or a fiberglass. If it is a fiberglass - it has internal mesh that may not work for KU band.
If it a standard mesh dish see if you can pass a pencil through the mesh holes. If you can it will not do KU very well.

When you cannot raise or lower the dish to increase your signal and it only causes your signal to drop you are dead on. Your c-band will peak too.

C-band is much more forgiving on tracking inacurracies than Ku because your dish has a much wider beamwidth for c-band since it is a lower frequency.

I forgot to ask if you are using a corotor or lnbf.

If you are using corotor you may simply need to adjust the skew of the polarization.

Good luck and keep us posted.

 

[tvropro]

Ku is 3 times more critcal to align than c band. If the Winegard is a Quadstar or a Pinnacle it will work well with ku, keep tunning, you'll get it .

 

[hoot550]

Ok, here's an update. I have spent most of the morning and up until late this afternoon trying to get this working.

Determined not to be beat by this, I hauled out a television and used it in conjunction with the signal meter. I found the analog signal on AMC 15 and used the picture, signal meter on the receiver and the one attached to the lnb. There is nothing, and I mean nothing I could do to get this signal to improve. Up, down, east west, skew adjusted--nothing. I again double checked and made very minor adjustments to the feedhorn and focal depth, everything under the sun. The strongest signal I can manage is next to nothing.

Do you think the lnb could be bad? I do not know much about the history of this dish, other than it set in a yard unused for several years. That, and there was one massive wasp nest in the feedhorn.

 

[linuxman]

Do you think the lnb could be bad?

It is quite possible that the LNB is bad.

There aren't any obstructions in the mouth of the feed-horn are there?

It is possible to get C-Band through a small amount of wasp nests etc, but not Ku.

Just a thought.

 

[hoot550]

No, there are no obstructions in the feed horn. I also live in the country and have clear sky all the way. I have been through everything, and tweaked and adjusted in every conceivable direction combination with no improvement. The wasp nests were at the very base inside the mouth, not up around the element at the top. There's a cover on it now, so they can't get into that part when the weather warms up.

I'm now thinking it might be worth it to check out a new lnb. But I am now torn between trying that option or going with a motorized ku only dish. I'm really only interested in having Ku for FTA, and using it as a slave is a pain at times. It would be nice to let the FTA receiver control the Ku side of things. Besides, I've got a nice new buried cable going out there just waiting for a new motorized Ku only dish.

 

[linuxman]

I'm now thinking it might be worth it to check out a new lnb. But I am now torn between trying that option or going with a motorized ku only dish. I'm really only interested in having Ku for FTA,

Have you tried FTA C-Band?

You really should tune the dish using the FTA receiver and the quality meter on it. The FTA digital signal will provide you with a much more accurate tuning than the analog signal will.

There is nothing wrong with having a separate Ku motorized dish, but you could have everything if you were to get a GBox V3000 and allow the FTA receiver to move the dish for it and the 4DTV.

If you are going to think about purchasing a new LNB anyway, why not explore a Geo-Sat Pro C/Ku LNBF.

I have one of them on my Birdview dish and have been very please with the performance. You could buy the C/Ku LNBf for about the same money you would pay for a Ku LNB.

Just some things to think about.

 

[gabshere]

if your running dual cables to the dish you can swap them to verify the cables are good

one of the connectors on mine was bad and gave a poor signal/ no signal new compression fitting and its like new.

i would agree with the G-box method its the best way to move the dish (with a dvb receiver)

 

[hoot550]

Thanks so much for all of your input. Actually I just replaced the entire cable from the dish to the house a few days ago and made sure my connections were working then. Replacing the cable is what started me fooling around with the Ku band issue again. The C-band FTA is working perfectly, excellent signal all across the sky.

I've thought seriously about the GBox positioner. I've become quite attached to the Toshiba Trx 2200 that came with this system, though. Had I not managed to find replacement bulbs for the lcd display, that's probably the way I would have gone. I'm pushing the money limit I wanted to spend on this setup. I have a feeling whatever I purchase will be the last amount of money I will be allowed to spend on this obsession, if you know what I mean.

Again, thanks for all of your help. I'm going to play around with it some more before I spend any money, but I sincerely appreciate everyone's input.