how to set the polarization on a bsc621-2d

[shankle]

Thanks for any help.

The bsc621-2d has no markings of any kind and no instructions
are sent with the box.
On my dish it needs to be set to right 0.87 degrees at the highest
point of the arc.
Is there something inside the feed horn to tell me how to orientate
the lnb or is it the label on the outside?

 

[Anole]

Just one reason I'm irritated with DMSI and their products.
Poor documentation.
I just looked at their main site for these pictures, and didn't find 'em... again! - :rant:

Luckily, we've got 'cha covered.

pix of skew for CK-1 and BSC-621 LNBf's
SatelliteGuys.US - View Single Post - Quick - Help me think this through! Geosat Pro C/Ku

 

[shankle]

Thank you Anole for taking your time to respond.
I'll go out tomorrow when I can see and check the ends of the bsc621-2d.
I think the ex: you gave was another make. I really doubt there are any
markings on the bsc621-2d. Will report back after I look.
The pictures of the dmsi site on the one view gave a web error.
But in any event the dmsi site only shows a front view of the lnb.

I presume the settings you mention should be done from the vertical
position of the dish. It's so high that way that I can't reach the lnb.

 

[Anole]

When I answered the above question about the Ck-1, I wasn't sure if the person asking had it or the DMSI 621...
So, if you'll notice, I gave pictures of both.
That 621 picture came off the old DMSI site, back when they had a little more documentation.

But, you're right, the two are totally different animals, from different companies, so they do -not- have the same markings.

 

[McGuyver]

You can take a TV & stb out to the dish and skew it without the need of any markings

 

[John Popper]

the bsc621-2d LNBF is the worst product I have ever bought when it comes to this FTA hobby, it's not even worth as a doorstop

you can follow my saga in these two threads:


http://www.satelliteguys.us/c-band-...172-first-time-setting-up-coolsat-6000-a.html

http://www.satelliteguys.us/free-air-fta-discussion/197532-whats-proper-dc-block-buy.html

 

[Lak7]

Is there something inside the feed horn to tell me how to orientate
the lnb or is it the label on the outside?

Drive the Dish to it's highest point (South Sat), pop the Feed Cap off. From behind the Dish, look up into the Feed, you should see a 1/4" metal rod, that should be horizontal.

 

[shankle]

Thank you Anole and others for your help.
I attached a picture of the bsc621-2d and as you
can see there is no contrast and without knowing
exactly where the mark is guys like me would never see it.
I am very sorry I wasted my money with this company.
You can be assured it will NEVER happen again.

 

[Lak7]

"Arrow" should be pointing to "12 o'clock" with Dish at South Sat.

 

[Anole]

It would seem that my pictures above were totally wrong.
Not surprising; the company has often changed the product without changing the documents.

Looks like what Lak7 said would get you to your goal.
Set the LNBF accordingly, when at the top of the arc (true south satellite).
Then, if that doesn't work, rotate the darned thing 90° and try again! -

I expect you should be able to get some signal out of it on C-band.


edit:

Drive the Dish to it's highest point (South Sat), pop the Feed Cap off.
From behind the Dish, look up into the Feed, you should see a 1/4" metal rod, that should be horizontal.

 

[shankle]

From your good advise I think I have gotten the BSC621-2d properly installed.
Dish is 120" and depth is 19". The Focal Point is 47.36".
It is centered in the middle of the dish with a stick thingy.
However, again no luck today.
My old system had two coaxes coming into the house and connected to a diseq switch. I am using the same setup for the bsc621-2d. There is no reason this
shouldn't work as the only thing different is the LNB. Right?
Still due to my troubles, is it posible that the bsc621-2d is NOT compatible
with the Pansat 2800a?

 

[Lak7]

Start simple...., Start with C Band only, no switches. Connect from the Receiver to the C Band side of the BSC621. The correct port should be marked "RCV".
Then triple check you have the correct LNB setting in the receiver.

 

[shankle]

Two Questions that might solve my problems.

1. Focal Point
dish width = 120" - D
dish depth = 19" -d
DxD= 120"x120" = 14400
16xd = 304
f = 14400/304 = 47.36"

f/D= 47.36/120 = .38"
should the lnb be set to 47.36" from the center of the dish?
OR
should the lnb be set .40" past the scalar ring?

2. elevation of the rocker arm
my latitude is 29.1024
my rocker arm is set to 29.62 (at the present time)
declination = 4.21
29.62 + 4.21 = 33.83
should it be set to 90 degrees minus 33.83 = 56.17?

As you can see the directions I have been reading are conflicting.
This has probably caused all of my problems.

 

[McGuyver]

Shankle, for what it's worth, I recently fabbed 4 feed poles for my BUD that was originally a monopole design and the calculator gave me approximately the same f/d measurements as your's and once the poles were installed and the lnb was mounted I found that the signal was strongest with the lnb clamped all the way down in the scalar ring. My dish has a large round plate in the center and this plate is flat, this indicated to me that any measurement should have been a little deeper than the plate would allow. I ended up with a longer f/d than I should have because I measured from the flat plate. My guess is that the f/d was about 1.25" deeper than the plate would allow, this difference would account for the flat plate vs a bowl shaped center. So if you measure from the center of the dish and your dish has a flat plate it might not be a reliable means of measuring. From what I have concluded, the lnb doesn't receive signals from the very center of the reflector where the plate is, if it had then the monopole mounting would likely cause interference with reception but in fact it doesn't. Don't quote me as this is only my educated conclusions with my 10.5' mesh dish.

 

[shankle]

I changed the FP to .40" past the scalar ring. Still getting nothing.

The idea of setting the rocker arm to 56+ degrees won't work as it put
the dish into the ground and way into the tree line. Can't be right.

I need to find a sat like satmex 5 which is C-band. I can't align the dish
on KU band satellites first. My western most satellites are all KU band.
useless to me.

 

[johann12]

"Arrow" should be pointing to "12 o'clock" with Dish at South Sat.

Wrong......

The arrow needs to be at 9 o'clock position looking at the coax connection.
That leaves the C band connector/ little box at about the 4 o'clock position.
But make sure that the dish is pointed at the most southern satellite.I live in North Carolina and in my case it is 83W, this was my best choice.

I have a 7 1/2 foot mesh dish and the scalar is set at 36.8 inches.You need to calculate it for your size of dish, unless you have a manual that came with your dish that may tell you.
Make sure that the scalar is square. Measure along each support tubing from dish edge to scalar, each length has to be exactly the same. Remeasure the distance between scalar and center of dish again to make sure it is the distance you need.
You can not just slab the scalar on the support arms, you could get poor quality signal or no signal at all especially in KU use. If your scalar is of by 1/2 an inch you lose about 50% of signal strength.
The BSC 621-2D LNBF is sticking out the backside toward the dish 0.8 inches.
You may have to move the LNBF in or out and adjust the skew a little bit, but make very small adjustment at a time.

You have to measure and adjust everything precisely because, KU on a c-band dish is not very forgiven and you will lose a lot of signal / quality very fast.

If you aim your dish and get KU, you always can bet that you can receive C band.

I have and use this BSC 621-2D with very good results. I can pick up just about anything with my S10 receiver, providing the receiver can handle the signal formats.

 

[KE4EST]

The arrow needs to be at 9 o'clock position looking at the coax connection.

I agree that is where my BSC has to be to work right. When I first got mine I pulled my hair our for about an hour thinking I got a bad one. I use a meter and my dish was already lined up right with another LNB. So for some reason I decided to tell the receiver to go to a populated C-band satellite and blind scan anyway....everything came in with the wrong polarity. So went out twisted it 90 deg and everything clicked right in. I found out I like it pretty well. I have several C-Band and C/Ku LNB's so always tinkering...right now I think there is a WSI on it though so can't give you readings.

 

[johann12]

47.36'' that is the distance your scalar needs to be, between dish and scalar.
The .40 is not inches in distance. It is a just a number used for F/D.

 

[johann12]

I would start with C band first.
Do not use any switches, just hook up your coax straight to the c band side. It is easier to hit the c-band than the KU band.
Set your receiver to 5150 LNB frequency.
Turn the 22 khz tone off
Then blind scan.
If I remember right, this is a universal LNBF.

 

[KE4EST]

Yeah it is Universal.