C Band Dish Installation Update

[FaT Air]

58W "at my southern most location", Are you on an Atlantic island I don't know about? Cape Cod, Ma* is 70W, plus or minus.
* going on what's listed in your sig.

 

[JFOK]

FaT Air,

I'll try 70W StarOne C2 and use that as my southern most satellite to find.
At times during those winter storms, Cape Cod sure looks like an Atlantic island
Thanks as always for your input.

John

 

[FaT Air]

Not sure if anything is up on 70W, at least I don't remember any posts.
May have to move the dish to the east, with the actuator, about 10 degrees (azimuth) and shoot for Vinesat.
(aka Simon Bollivar) 3885 V 23000
1/3 of an hour using watch face.

 

[gpflepsen]

I would get the dish pointing at the apex of its travel. Then rotate the mount on the pole to find 58. Treat the mount as a pure AZ/EL mount. Mark the pole with a reference mark to the mount. Repeat the aim for 83w and make another mark on the pole.

Now, you have two marks, one for 58w and one for 83w. Make another mark on the pole that's measured to be proportionally equal to your exact longitude. Rotate the mount to this reference mark; now you are aligned to your true South. Lock the mount down there and never move it again.

Ensure your mounts rotational axis is inclined to your latitude, or a bit more if your doing modified polar.

I would expect the +/-10 skew to not be that detrimental, so leave the lnb at 0 skew.

Getting the dish oriented @ true South is most of the battle, then everything else kinda falls into place.

Anyone disagree with my skew comment?

 

[JFOK]

gpflepsen,

Thanks for your reply.
My true south was actually pointing between 58W and 61W as far as I can figure taking 2 compass readings.
However FaT Air believes StarOne at 70W is more accurate and he may very well be right. I'm far from being an expert.

John

 

[FaT Air]

ok some questions:
Actuator on a polar mount, or AZ-EL with no actuator?
Your latitude and longitude (so I can 'crunch' your numbers).
That will also 'tell' what your 'south satellite' is.
How about a pic from the side, with the dish at apex, far enough back to see the whole dish?

I would get the dish pointing at the apex of its travel. Then rotate the mount on the pole to find 58.

Wont find 58 as the dish apex will be much higher than the satellite at 58.

 

[gpflepsen]

ok some questions:
Actuator on a polar mount, or AZ-EL with no actuator?
Your latitude and longitude (so I can 'crunch' your numbers).
That will also 'tell' what your 'south satellite' is.
Wont find 58 as the dish apex will be much higher than the satellite at 58.

Treat the mount as an AZ/EL mount. Elevation will need to be adjusted for 58w. If he's @ 70w Lon, 83 will be about the same elevation.

The point is to get the rotation axis pointed to true South. I use this one...

Get a good compass or use an app.

 

[FaT Air]

I'm wondering if some angles are transposed, reason for the picture.
Also, what type feed? LNBF or a corotor? Sure of it's skew? May be 90 degrees 'off' making V=H and H=V. (I've done that) Make/model? picture?
Cape Cod is at 70W (+/-) so the south satellite would also be 70W.
But there's no known TP's receivable here in N.A. to my knowledge.
Reason to move the dish with the actuator 10 degrees and shoot for 78. The vertical angular difference between 70 and 78 is under 1 degree at his location. So a perfect 10 degrees isn't a necessity.
The TP I listed is the only one, I know of, but it's a good strong signal.

I'd refer to www.dishpointer,com and zoom into the dish location. Get a reference on the ground to aim towards, should be very close.

 

[JFOK]

FAT Air,

Dish is on a polar mount.
Latitude: 41.6662°
Longitude: -70.3553°
Here's that picture of dish at what I believe is apex.
** Feed horn is a Precision/ADL with a C/Ku LNBs.**

Thanks,

John

 

[FaT Air]

While I crunch numbers and annotate some pictures verify that the feed probe is vertical and horizontal when Vertical is selected and H when Horizontal is selected.
Thank You

 

[N6BY]

FAT Air,

Dish is on a polar mount.
Latitude: 41.6662°
Longitude: -70.3553°
Here's that picture of dish at what I believe is apex.
** Feed horn is a Precision/ADL with a C/Ku LNBs.**

Thanks,

John

Based on your latitude, at its apex your dish should be elevated 41.9 degrees. It looks pretty close to that in the photo

To be sure, you might want to use a digital level. I have one and it saved me from a lot of trial and error.

Edit: Didn't see FAT Air's post while I was typing. Looks like we agree on the 41.9. And your dish in the photo looks it may be a degree or 2 too high.

 

[gpflepsen]

If you have a decent smart phone, try this for a level. I love it.

 

[FaT Air]

OK, using the modified dec numbers, the polar mount should be at

and with modified' declination of 5.85 the dish ring measurement,
measured on the dish 'ring' or a straight edge across the dish face. Top to bottom lip.

checking: 90 - 48.5 = 41.5
The angle to 70W is (according to dishpointer) 41.9°
An error of .4, not bad. (for these numbers I rounded the latitude to 42) That will get straightened out once 78 is found (with the actuator having move the dish slightly East)
As is looks like your Declination is near '0'.

 

[FaT Air]

Showing the perpendicular of the dish angle
equal the elevation of the arc at zenith.

 

[JFOK]

FaT Air,

I've closed up shop for tonight. The frustration level was increasing and I've been at this since 9:30 AM.
I can't imagine why this dish isn't working. I've been working on this for a week now.
My first set up in 1991 was a 9 foot Radio Shack deal and I had it up and running in two days.
Of course analog satellites were easier to find.
To answer your question, the feedhorn probe was in its proper H and V modes when needed.

N6BY,

I have the dish set at 42 degrees, I rounded off the latitude and checked it several times during the day...never changed.

gpflepson,

Thanks for the suggestion for the level. I've been using the Stanley smartphone bubble level that Brian recommended, along with an inclinometer.

Thanks to all of you who offered help. Looks like I'm going to continue to need it. Today was a BIG disappointment.

John

 

[FaT Air]

Yeah, I have felt 'the feeling' a few times. Especially when overlooking some small detail.
A day or two later things will get clearer, and you'll have the arc tuned.

 

[JFOK]

FaT Air,

I really appreciate all the effort you made with those diagrams, using my dish picture.
I had set my latitude at 42 rounded off from 41.6, so I set the declination at 5.85 giving me a total of 47.85 degrees.
However you said my declination looks to be 0. Can you explain ?
Guess I have more tweaking to do.
Thanks again.

John

 

[gpflepsen]

Just a thought....

Are you using a receiver as a signal level meter/finder? Are your setting correct for lnb L.O.? Any other settings incorrect?

I'd use the NHK transponder on 58w and the Luken tp on 83w. Make sure you're capable of getting S2 signals if you're looking for them. Just going back to cover some basic start points.

 

[FaT Air]

May just be the angle the photo was taken at. but looks parallel.

compared to (From the BUD MANUAL)

One way to measure the Latitude+ declination angle with great accuracy, without the mount itself in the way, is place a 2x4* long enough to span the face of dish from top to bottom. Measure the angle on the 2x4.
*A taut string may suffice.
FWIW: Have you checked for the feed centered over the dish and pointing at the center of the dish?
(You know, Just realized I didn't give credit for that picture & I can't remember what member said I could use their picture for my use, but Thank you)

 

[JFOK]

FaT Air,

Here's a close up of my dish from that same picture you worked with.
I think you can see some declination, but more may be needed.
I did check that the feedhorn was centered, but do you have a surefire method yourself ?
Thanks again.

John