Weekend experiment for 30W with a little dish

[Jason S]

I've been wanting to see what's on 30W for a while but I don't have a motor on either of my Ku dishes yet; and the one I'd be willing to move is blocked by trees.

Searching and reading on Satelliteguys and some photos of Fred555's setup gave me some inspiration. I decided to try an old pizza pan that had been thrown in when I got the 7.5' Echostar.

So on Thursday night I removed the circular LNBF's and plastic Y-yoke from the pizza pan. For the linear LNBF setup, I used a universal bracket to hold the LNBF. The LNBF holder is attached to the dish arm by an extension with a slotted adjustment drilled into it.

I did some measuring and comparing of the old LNBF position to the new. Satisfied things were in about the right spot, I riveted the extension to the pizza pan arm.

Friday afternoon, I made a skid onto which I mounted the modified dish. Then I brought out a spare TV and receiver. I picked 97W to use for fine tuning the new LNBF setup, as well as to see what could be expected for Q on the receiver.

The initial settings I had for the new LNBF were pretty close. I messed with the height and distance for a little bit until I thought things were as good as could be expected.

Here is the 'new' dish peaked on 97W:


Elevation and skew look fairly normal while on 97W...

On Saturday, I moved the skid with dish over to an area about where I determined 30W could be found. I had previously entered active transponders manually into the receiver.

I skewed the dish to what dishpointer.com indicated and then lowered the elevation so that the dish itself was nearly plumb. I switched on the receiver and set it to an active transponder and watched the Q. I then lowered the dish and lowered it some more and finally had a lock. I tuned the dish a bit more and then scanned in what I could...

Here are some photos of the dish once I got 30W locked in on Saturday and one from today.


The LNBF arm extension was modified from a bracket I had originally made for an offset LNBF setup for one of my 1.2m dishes...

 

[KE4EST]

Thanks for sharing. That's the way it is here looks my dish is pointed into the side of the mountain.

BTW are those 1974 GMC trucks?

 

[fred555]

Lookin good. Those pizza pans can sure hone your aiming skills! Don't watch too much Sexysat, you'll go blind!

 

[Jason S]

Thanks for sharing. That's the way it is here looks my dish is pointed into the side of the mountain.

BTW are those 1974 GMC trucks?

The dish position sure looks odd...

The trucks: left side of photo is a '74 Chevrolet K-10, shortbed 4x4 and the one on the right is a '73 GMC K-2500, longbed 4x4 Camper Special. The '74 was a ground up rebuild/restoration in early 2000's and the the '73 was a rolling rebuild.

 

[Jason S]

Lookin good. Those pizza pans can sure hone your aiming skills! Don't watch too much Sexysat, you'll go blind!

I was sure surprised to see that channel once I had everything scanned! I think setting the dish up on 97W initially helped me with aiming for 30W; however you're right, there is very little margin for error on the little dish...

Thank you again for uploading your photos.

 

[DK_Sat]

What receiver you are using to find the signal on 30 w

 

[spongella]

Great setup Jason S, I like that wooden pallet mount. Hispasat is probably second to 97W as far as the # of stations out there. Only one with Cuban FTA too.

Nice work and thanks for the pictures.

Sponge

 

[Kraven]

Don't watch too much Sexysat, you'll go blind!

??

 

[jorgek]

I've been using this 25" round offset dish for many years to watch 30w. Lots of people said it would not work.

 

[Jason S]

What receiver you are using to find the signal on 30 w

It's a Manhattan RS-1933 receiver and a Titanium PLL-Ku LNBF.

I searched Satelliteguys to find active transponder information. Active transponders were then manually input into the transponder list in the receiver.

 

[Jason S]

Great setup Jason S, I like that wooden pallet mount. Hispasat is probably second to 97W as far as the # of stations out there. Only one with Cuban FTA too.

Nice work and thanks for the pictures.

Sponge

Thanks! The wood skid/pallet is not a permanent setup, but it'll allow the dish to be moved around the yard to where it would have the best line of sight.

 

[Jason S]

I've been using this 25" round offset dish for many years to watch 30w. Lots of people said it would not work.

Some of your posts about 30W on a small dish were what sparked initial interest in trying this.

I sure didn't know what to expect as far as quality. It was interesting to see what would lock and at what Q, especially when I was tuning on 97W.

From the Q indicated on the receiver, there are a few transponders on the verge of being locked but I think there just isn't enough dish. There are other transponders that will lock, but there isn't much margin for any signal loss...

 

[jorgek]

An 18" or 20" is too small. I tried both on 97w and only locked onto a couple of TPs. I didn't bother to try 30w.
On the other hand the 25" on 30w is very reliable with the GeoSat PLL LNB. I lock onto 16 TPs and average Q 70.

 

[a33]

I skewed the dish to what dishpointer.com indicated and then lowered the elevation so that the dish itself was nearly plumb.

I like your wooden skid ! Very practical for testing practices!

But I'm wondering: Since I guess you have no intention of making a multi-feed dish out of it, why skew the whole dish? I would guess skewing the LNB would have exactly the same effect and would be much easier...???

greetz,
A33

 

[fred555]

I have read around here that at the ends of the arc (such as 30W), skewing an oval dish on a weaker transponder may gain a few points in Q, round dish not so much. Anything for just one more point. I find that it is easier to adjust. It is like a big steering wheel and you are behind the dish making the adjustment, not up front blocking the signal. And I do it just because I can and like the sideways look. Either way will work but FTA is all about experimentation for me.


Here are a few posts on the subject:
http://www.satelliteguys.us/xen/threads/lnbf-skew-vs-dish-skew.150840/
http://www.satelliteguys.us/xen/threads/lnb-skew-vs-dish-skew.263320/

And, Welcome to the forum a33!

 

[a33]

I have read around here that at the ends of the arc (such as 30W), skewing an oval dish on a weaker transponder may gain a few points in Q, round dish not so much.

Hi Fred,

Thanks for the links to the posts.
I read them, but cannot think of a reason if you have a "normal" offset dish, that dishskewing would have more/a different effect at the ends of the arc. The LNB "sees" a round dish, and the satellite "sees" a round dish. The dish does not change anything about the polarized signal (except mirroring), so I don't see that it would be any different from skewing a prime-focus dish: No difference between LNBskewing or dishskewing I would think!
So, I don't see the benefits.
All could be different with a "not normal" offset dish, of course.

And I do it just because I can and like the sideways look. Either way will work but FTA is all about experimentation for me.

Ah! But that's an argument I can't argue about...

Greetz,
A33

 

[Jason S]

a33,
Thanks for the compliment on the skid! Honestly, I kinda threw it together from scraps I had from building a fence and some other bits. I was just ready to try out my dish modification. The orange box is an old Stihl chainsaw box that was needed to keep it weighted down.

I think Fred555 has the best answer for your question about skewing the whole dish, but I'll throw in this bit...

The practical answer on the dish skew: the dish I used is marked incrementally every 2° from 36° to 144° on the back for skew. So for my -49.9° skew, it's a bit easier to set the whole dish at 50° skew and do any fine tuning at the LNBF... End result, skewing the whole dish on 30W is something definitely odd...

Along the lines of experimentation (just like Fred said)- I've never been able to skew a whole dish.

BTW, welcome to the site. There's definitely a great and friendly knowledge base here!

 

[bigg t]

I,ve been using an old dtv dish here on 30 deg for about 2 years. It,s the only dish that i have ever used to get it. I get enough signal to get Cubavision with a signal in the 70,s on the Amico A3. I,m using a universal lnbf holder with a standard lnb. I did,nt need to extend the arm on it , just skewed the lnb. The motorized 1 meter being blocked by trees was the reason for this setup.

 

[Corrado]

These projects are always fun. Thanks for sharing Jason S.

I have been using an old oval Primestar dish and more recently a recycled Dish Network 500 with a rigged LNBF for several years. Mainly in the Winter when the leaves are down and I can place the pallet on the lawn without killing the grass, somewhat near the other dishes to access the switches and cabling.

The old Dish 500 works fine even when I can only see the dish itself sticking out above the snow line.

 

[Jason S]

Weekend update:

The little Dish dish remained on the skid through the winter. However, once the leaves came out, I started losing Q until finally there was nothing. So with the leaves out and the grass needing mowing, I disassembled the setup and moved the skid...

In the meantime, I saw a Wild Blue dish sitting in a scrap metal pile waiting to be hauled off. I asked the owner and they gave it to me. Yippee! I thought...

I brought the "new" dish home and shortly thereafter began to fabricate a bracket for an LNBF holder to fit the dish.

To make the slot, I drilled a series of closely spaced 1/4" holes. Then I broke out the metal remaining between the holes and used a file to bring the slot into shape.

Here is the new LNBF (Titanium Ku-PLL) and bracket mounted to the dish, with the original equipment still mounted for a comparison.


As I began to reassemble everything and do some measuring and looking closer, I discovered the main reflector was twisted and the sub-reflector mounting arms were misaligned (i.e., bent). I think this thing took a hard hit.

I was able to get the main reflector to pop into shape by removing it from mount and laying it flat on the concrete shop floor. I used a rubber mallet and with a few judicious blows, the main reflector popped into place.

The sub-reflector is a different story. I tried to gently pry the arms to reposition them, but no luck. I then tried some brute force which broke one of the mounting arms. Having several hours into the project, I figured "in for a penny, in for a pound" and bent some sheet metal to replace the broken section.



To test the dish setup, I reused the skid with the Dish J-pole. The Wild Blue mount requires something closer to 2-inches, so I just shimmed the J-pole. This was during a break in the rain, so I just wanted a quick test.


Using 97W to try out the dish and with very little adjustment, I was able to get a pretty quick lock. I didn't mess around with it too much. I was happy that it worked with a good and stable Q and left additional tuning for later.





Now that I had some confidence in the dish and after researching on dishpointer.com where I could get a line of sight for 30W, it was time to place the dish. I've been in the process of moving dishes around and had to wait to 'free up a line' to get the Wild Blue mounted.

Once I got the other dishes moved (another story), I mounted the Wild Blue and peaked on 30W. So, here it is mounted and aimed on 30W. As for the mounting, I had to modify some 2-inch I.D. conduit to allow the Wild Blue mount to fit.