Help with new C band dish

Status
Please reply by conversation.

rrob311

SatelliteGuys Pro
Original poster
Nov 25, 2010
941
16
New England
I bought a 12 foot Com-tech Portable dish. I am lost as how to setup the Feedhorn and LNBs on it. There is a cover on the front of the feedhorn and on the side. It looks like you can bolt LNBs to both covers. There is also a couple of gears. Is this to adjust Skew? I am also not sure how to set the elevation. I would like to point it at 87w, 91w, or 135w. I know how to setup Ku dishes but I am new to C-band. I already have the mount level on it. Does anyone have any recommendations on which LNB to buy? There is no motor control for this.
 
satfull.jpgsat lnbs.jpgsatfeed.jpegsathorn.jpg
 
rrob311 said:
I bought a 12 foot Com-tech Portable dish. I am lost as how to setup the Feedhorn and LNBs on it. There is a cover on the front of the feedhorn and on the side. It looks like you can bolt LNBs to both covers. There is also a couple of gears. Is this to adjust Skew? I am also not sure how to set the elevation. I would like to point it at 87w, 91w, or 135w. I know how to setup Ku dishes but I am new to C-band. I already have the mount level on it. Does anyone have any recommendations on which LNB to buy? There is no motor control for this.

Where the covers are you install cband lnbs.

This feed horn gives you both H and V polarities.

I've not seen the gears before but would guess and agree this is for skew, kinda cool!
 
rrob311 said:
I bought a 12 foot Com-tech Portable dish. I am lost as how to setup the Feedhorn and LNBs on it. There is a cover on the front of the feedhorn and on the side. It looks like you can bolt LNBs to both covers. There is also a couple of gears. Is this to adjust Skew? I am also not sure how to set the elevation. I would like to point it at 87w, 91w, or 135w. I know how to setup Ku dishes but I am new to C-band. I already have the mount level on it. Does anyone have any recommendations on which LNB to buy? There is no motor control for this.

"portable dish" LOL!
 
Can't see the back side of the dish, but I'll bet there's a place you can stick in inclinometer.
I wouldn't want to take a 12' board up the middle on the front side, just to check the elevation. :)
The mount being plumb may not really matter much for fixed operation (more critical if you're motorized).

That knob below the feed looks like your skew.
Maybe you pull down on the lanyard, then twist the knob half a turn at a time (?)
Suspect it'll be obvious to ya, once you play with it a bit.

For the dirty middle of the dish, I'd go with a power wash.
Some guys have discussed a stiff brush, hot water, soap, and maybe a little bleach for cleaning.

You've already got an orthomode feed (two LNBs, one for each polarity).
And a fancy matching scalar.
Life doesn't get much better.
Not sure how to clean it, though. Kinda have a similar problem myself.

Depending on your intentions, you might go with inexpensive LNBs like these from Galaxy Marketing.
Think HyperMegaSat is one of their dealers (unless I am corrected).
Or, you could invest in higher quality Norsat 8515 LNBs, such as these.
Considering it's a 12' dish, and not motorized, I might just go with the cheaper ones.
Yes, you need two.

To hook the LNBs to your receiver, most folks use a multiswitch, like a 2x4, or 4x4.
Pendragon described a very nice 4x8 that is very cheap (see the thread).
While it may seem overkill, it was the cheapest solution I could find.
The mod gives 18 volts to both the V and H LNBs for best performance.
You can try an unmodified multiswitch at first, and see if the Vert transponders seem compromised (should still work).
Even a lowly $5 surplus 2x2 multiswitch would be enough, but stumbling over one is less likely.
 
Can't see the back side of the dish, but I'll bet there's a place you can stick in inclinometer.
I wouldn't want to take a 12' board up the middle on the front side, just to check the elevation. :)
The mount being plumb may not really matter much for fixed operation (more critical if you're motorized).

That knob below the feed looks like your skew.
Maybe you pull down on the lanyard, then twist the knob half a turn at a time (?)
Suspect it'll be obvious to ya, once you play with it a bit.

For the dirty middle of the dish, I'd go with a power wash.
Some guys have discussed a stiff brush, hot water, soap, and maybe a little bleach for cleaning.

You've already got an orthomode feed (two LNBs, one for each polarity).
And a fancy matching scalar.
Life doesn't get much better.
Not sure how to clean it, though. Kinda have a similar problem myself.

Depending on your intentions, you might go with inexpensive LNBs like these from Galaxy Marketing.
Think HyperMegaSat is one of their dealers (unless I am corrected).
Or, you could invest in higher quality Norsat 8515 LNBs, such as these.
Considering it's a 12' dish, and not motorized, I might just go with the cheaper ones.
Yes, you need two.

To hook the LNBs to your receiver, most folks use a multiswitch, like a 2x4, or 4x4.
Pendragon described a very nice 4x8 that is very cheap (see the thread).
While it may seem overkill, it was the cheapest solution I could find.
The mod gives 18 volts to both the V and H LNBs for best performance.
You can try an unmodified multiswitch at first, and see if the Vert transponders seem compromised (should still work).
Even a lowly $5 surplus 2x2 multiswitch would be enough, but stumbling over one is less likely.

Cool I ordered 1 lnb for it I suppose I will order another now. The dish came with an inclinometer. The LNB that came with it has a different fitting on it. I think it came with some of the switches you speak of but they have the bigger style connector on them. You aren't talking about the Diseqc switches are you? I have several of those. It also came with a smaller feedhorn which I think the guy said was for Ku but I just want Cband for now.
 
Multiswitches provide 2 polarities to multiple receivers. They're a great way to combine 2 lnbs into a single cable for receivers that use voltage switching.

Back in the day, including 4dtv, receivers supported 2 inputs, 1 per polarity, most today use voltage switching on a single input.

The Ku lnb flange will be smaller and square compared to the cband rectangle shape. The collector or arm for ku is different to cband. From your pictures it doesn't look like the feed horn supports ku.

For an example check out the chaparral supercorator which supports cband and ku on a single feed horn using a polariser servo.

Just reread your last post, you have a separate ku feed horn which is correct.
 
Multiswitches provide 2 polarities to multiple receivers. They're a great way to combine 2 lnbs into a single cable for receivers that use voltage switching.

Back in the day, including 4dtv, receivers supported 2 inputs, 1 per polarity, most today use voltage switching on a single input.

The Ku lnb flange will be smaller and square compared to the cband rectangle shape. The collector or arm for ku is different to cband. From your pictures it doesn't look like the feed horn supports ku.

For an example check out the chaparral supercorator which supports cband and ku on a single feed horn using a polariser servo.

I think the ku feed has a different feedhorn. So I need to get a multiswitch to plug the 2 lnbs into a main coax which I can then feed into a diseqc switch?
 
rrob311 said:
I think the ku feed has a different feedhorn. So I need to get a multiswitch to plug the 2 lnbs into a main coax which I can then feed into a diseqc switch?

Basically, yes.

2 lnbs, 1 polarity each will go into a multiswitch 13volts and 18volts.

You could then connect a receiver directly to the multiswitch, to a receiver port. The receiver will switch polarities using voltage.

You only need the disecq if you have multiple dishes that you want to use on the same receiver.

What the multiswitch does is effectively turn the 2 lnbs into a lnbf.
 
Status
Please reply by conversation.
***

Users Who Are Viewing This Thread (Total: 1, Members: 0, Guests: 1)

Who Read This Thread (Total Members: 1)

Latest posts