7.5' Sami Ku problem

[ajvp]

Hopefully some one can point me in the correct direction. I'm having a Ku / feedhorn / dish problem.

I have a Sami 7.5ft C-band dish with .040 mesh holes and a VonWeise 48 pulse 24" acutator. It has been C-band for years w/o any problems. I decided to install a co-rotor (that I had in the garage for the past 7 years.) I couldn't find the polar template but I did set it tobe at the 11 o'clock position with the Ku lnb upward.

I have checked true south, declination, dish warpage, feedhorn F/D and rotation and everything else I can think of including a new Ku lnb, swapping wires and using my spare GI650. But apparently, something is off. The only Ku I can pickup is 101w and it shows to be 21 pulses to the east from my 101w C-band. (i.e., 101w c-band is at 5330 but 101w Ku is at 5309.) The dish is in good shape with no panel damage.

What did I miss? Do I have the co-rotor sideways or something?

Thanks for your time.

 

[knowmiddlename]

IMO, making the 7.5 SAMI work on Ku is just not practical. I own one too and there are way too many issues. I prefer using a separate 1.0m or 1.2m for Ku. You'll be far less frustrated and much happier with that arrangement.

 

[ajvp]

Yea. I'm starting to think you're correct. I had several P* dishes up and condensed them to one with a stab 120 motor that I use on one receiver. I just had the corotor (sitting in the garage) and thought I would give it a try. Have been trying to reduce the number of dishes in the yard.

Update: With more tweaking I was able to get
101- was 21 clicks off its c-band counterpart
97 - 14 clicks off
96 - 11 clicks off
But that was it.

Next, I think I'll try to attach a circular lnbf to the side. We'll see how that goes.

Thanks

 

[Davage]

ajvp - Thanks for the testing you've done. You've saved me a bit of time. I have the exact same setup as you - a 7.5ft Sami with 24 inch Von Weise actuator.

You can see a picture of my setup at this link --> http://www.satelliteguys.us/c-band-satellite-discussion/208680-installed-new-old-actuator.html

I also have a Co-Rotor sitting here in my basement that I was considering hooking up, but after hearing your results, I think that I'll stick with a dedicated 1 metre Ku dish instead.

 

[Anole]

- where have we heard this . . .

I have a Sami 7.5ft C-band dish with .040 mesh holes and a VonWeise 48 pulse 24" acutator.
It has been C-band for years w/o any problems.
I decided to install a co-rotor ...

Update: With more tweaking I was able to get
101- was 21 clicks off its c-band counterpart
97 - 14 clicks off
96 - 11 clicks off

This sound suspiciously like the problem some of the members had two years ago.
They were trying to get dual-band LNBFs like the CK-1's to work on Ku, at the time.
The problem was minimized and solved, by
- careful location of the LNBF to the exact center of the dish, and
- proper aiming (with laser pointer) to the dish center, and
- fine tuning the F/D and skew.

So, a question to our more experienced BUD-users:
... is the SAMI 7½ foot dish a sloppy dog?
... or would a more careful retuning of the dish help this problem?

 

[ajvp]

As for me... I'd have to go with the "sloppy dog." As far as the alignment it does seem to be VERY tempermental. The slightest movement and it looses what Ku I have found. As I said b/f, I have checked, rechecked and rechecked again all the alignment and I have them pretty much dead on.

I had another co-rotor on my 10 footer (which sat next to the Sami) and it worked just fine. Keep in mind that the old 10 footer was not pretty. It had a button hook with guy wires across (in several places) and 12 wires going to the button hook to hold center. But, finally it just got to be in such bad shape that extra wires just wouldn't help and I had to take it down. I have been thinking about replacing the mesh of the Sami with the mesh from the 10 footer. I just hate to cut the mesh incase I need it for something else.

I can understand seeing fewer birds (probably b/c of the smaller dish and the slightly larger mesh.) The only thing that still throws me is the Ku being off from the C-band. Oh well.

 

[DK_Sat]

I have a 7.5' Unimash dish with Chaparral Corotor II Plus International Wideband Feedhorn and i have no problem receiving KU satellites , Dish tracks from 27,5 w to 137.0w

 

[ajvp]

Do you know how big the holes in the mesh are on that Unimesh?

 

[DK_Sat]

The mash on the Unimash and Sami dishes is the same. The Orbetron dishes came with micro mesh.

 

[ajvp]

Now that was just soooo not what I wanted to hear.

That puts me back to 'why' mine has a problem. I do have a Ku lnbf bracket mount for C-band. I may give it a try.

 

[truckracer]

I have a sami 7.5' and 10' both have corotor II feedhorns with Norsat LNB's...Ku booms in on both.
I tried a dual band lnbf (BSC-621) was a total failure on KU. You will hear mixed opinions on those dual band lnbf's but i can tell you if you want the best reception...get a corotor feedhorn and lnbs.