Here we go again..

[Dee_Ann]

Obviously I don't have enough misery in my life so today I decided to take on the BUD again.
Rather pointless since I'm moving soon but again, I guess I needed to punish myself some more.

I had a Titanium C1PLL in place and it was pretty much mostly working. Not as well as it could but I figured that was a result of not having it aligned properly.

Some months ago I bought a pair of C2wPLLs but they have just sat gathering dust after I found out about moving.

Today I decided to go put one on my 10' BUD. It's an ODOM brand. That's all I know about it..

In the past I've never once taken to using any scientific or mathematical methods of aligning it, not even a little. I would just spend weeks futzing with it until I got lucky and hit something then I would just go full hands off and leave it parked on one satellite for months or years.

What really set me off on it again was that all of a sudden MeTV vanished for no good reason. So I figured I might as well go change the LNBF and see if I could get all precise like with it this time.

So, I took the LNBF and using a straightedge I drew a line down the outside of it that is perfectly aligned with it's ZERO mark.

Then I took a string and some clamps and I pulled a string line from the edges at the top and bottom and laid the string over the LNBF holder so that it was aligned perfectly with the center line of the dish and in prefect alignment with the polar mount.

Then I climbed the ladder and made a mark on the holder where the string was laying. If the dish were stood on it's edge perfectly vertical the mark I made would be at the exact top.

So then I put the new LNBF in the mount and lined it up with the new mark I made. This would put the LNBF so it's zero mark is perfectly aligned with the centerline of the dish.

I swung the dish back up and much to my dismay, nothing.. No signal at all.

Then I thought it might be the F/D (I don't fully understand what it even means and I certainly can't do the math) so I went the route of trying random settings, which got me nowhere at all.

Finally I decided to look up something about it and I read that you tie a string across the dish and measure the depth. I did that and it came out to 21 inches deep. I found a calculator for dishes and I put in the 10 foot and the 21 inch depth and it told me that the F/D should be .357 (I found this out after I already gave up for the night)

What makes this really difficult is that the dish is so big that I can not reach the LNBF without tipping it all the way over and then I have to climb up on a ladder. When it's tipped into the proper position for viewing, I can't reach anything even when I'm on a ladder. What I need is some sort of platform that I can extend into the dish that I can walk out on, mess with stuff then retract it back out of the way. But that's not likely to happen.

Since I have to tip it back and forth it's really hard to work on and I spend a great deal of time walking back and forth into the house to operate the motor.

Oh, also, I am reasonably confident that I have the elevation and declination set pretty close to what it should be, I expended a great deal of effort and angst over figuring that out much earlier this year. I also found a way to ensure that I have the azimuth set dead on as well.

What I'm not real sure about is should I have the LNBF aligned perfectly with the centerline of the dish?
Doesn't it like, change the skew as the dish tips, like a KU USALS does? I know on them you set the LNB to zero skew and the dish tips to change it.

Or am I completely missing something here? I'm thinking of going out to try changing the F/D now that I found a little calculator for it. I'm thinking that I had it wrong today. Obviously something was wrong as I could not find a signal at all after changing the LNBF.

 

[Dee_Ann]

This little calculator I found via google gave me the following information. I didn't know what to put in the frequency box so I left it at it's default of 4.2ghz.

 

[FaT Air]

So then I put the new LNBF in the mount and lined it up with the new mark I made. This would put the LNBF so it's zero mark is perfectly aligned with the centerline of the dish.
I swung the dish back up and much to my dismay, nothing.. No signal at all.

Is this with existing transponders in the receiver?? Did you try a blind scan? Could be the polarity is off by 90°. Could need the '0' mark at 3:00, Don't know for sure tho==i may be wrong.

 

[Dee_Ann]

Actually I was using my meter, the AI Turbo S2. I made sure that I configured it for "Generic C-band, dual polarity LNBF, 13/18v"

As for the LNBF, I just don't know how it's supposed to be. I thought the zero mark on it went to the dead center top, as if everything was standing on edge, vertically, the zero would be at the 12 O'clock position. Yes?

 

[primestar31]

Actually I was using my meter, the AI Turbo S2. I made sure that I configured it for "Generic C-band, dual polarity LNBF, 13/18v"

As for the LNBF, I just don't know how it's supposed to be. I thought the zero mark on it went to the dead center top, as if everything was standing on edge, vertically, the zero would be at the 12 O'clock position. Yes?

ONLY when the dish is pointed at exactly dead south (top of arc). Then it skews itself properly as the dish moves from sat to sat. So, if the dish was pointed anywhere else when you did this, it'll be wrong.

 

[Dee_Ann]

ONLY when the dish is pointed at exactly dead south (top of arc). Then it skews itself properly as the dish moves from sat to sat. So, if the dish was pointed anywhere else when you did this, it'll be wrong.

Right-O... And that's why I put the string along the polar center of the dish, from it's 6 O'clock position to it's 12 O'clock position.
Previously I had just guessed at it and went by eyeball alignment.

Anyway, after Doctor Who was over I went back out and set the F/D to .35ish and BAM! FTA GOLD!!

I got MeTV back and for the first time EVER, I'm getting Luken stuff on 87 like it's being piped in over fiber optic!

I am suspicious though of the "focal length" though. I was reading over at this page, http://www.geo-orbit.org/sizepgs/tuningp4.html
and it says you measure from the center of the dish to the to the front of the polarotator. Well since these LNBFs don't have that I'm assuming you would measure to the first little wire antenna inside the can?

I have never known about this measurement, I just snapped to that tonight when I read it for the 100th time.
I noticed there is a bolt where you can adjust how far the LNBF holder sits away from the dish and I guess it would let you rotate it as well.

So I put my tape measure against the whole thing and it seems the LNBF is a good bit further out than the calculator thing and the article suggests it should be.
But then again, what do I know? Besides, it now seems to be working better than it ever has before so maybe I should just leave it alone for now?
I'm going to be tearing it all down in less than a month anyway.

 

[primestar31]

Leave it alone! lol...

 

[Dee_Ann]

Leave it alone! lol...

Sound advice that I think I shall follow this time. It seems to be working. I better stop trying to fix it while I'm ahead of the game.

 

[Dee_Ann]

Actually, this is the best I've ever gotten this dish to work after having it up like almost 5 years.

 

[mmewrench]

In most cases you wont get the focal distance and the F\D ratio adjusted perfectly unless you have a way of moving the scaler closer, or further from the dish. Most of the newer dishes do not have this adjustment.

I have to agree with Primestar. Leave it alone and watch TV. Once you move in to the new house, you can take your time setting it up. The last time I upgraded to a new Bud (12 footer), I had the feed set up before I hung the dish on the pole and haven't touched it since.

geo-orbit.org has a goldmine of information. Read it all (over and over), and the next time you set up that Bud it will be so simple it will scare you.

 

[Dee_Ann]

Cool beans... I'll do that.

I guess I will set up my FTA dishes when I move after all. I had really become very discouraged and was ready to just give up and quit.
But maybe I was a bit hasty. I'll set them up over there but I won't be in a huge hurry to get it done like I was planning on.
I'll make moving priority one. Maybe in next month or January I can do it. If I just worry about doing one dish at a time I can do it myself.

 

[gabshere]

Dee-ann
i aways like reading your posts not for the misery part but the story i have the other version of your dish which i hope to pull down next year and rehab a bit seems to have a bit of aged parts and hail damage ... 10 ft ODOM with 4 feedhorn support arms although the button hook you have seems to be doing well ...

 

[primestar31]

I've had a few times myself when I just HAD to try to get that last little bit of performance, and made an adjustment that should have been quick, but ended up causing 5 hours or so of grief.

Sometimes you really do get it nearly perfect the first time out (even if you don't recognize that it is ok as-is), and any more playing with it just causes big trouble.