This is a mobile optimized page that loads fast, if you want to load the real page, click this text.

Multiple LNBF on BUD

Status
Please reply by conversation.

equant

SatelliteGuys Pro
Original poster
Apr 23, 2007
265
0
Tucson, AZ
A few weeks ago I decided to try and add a Ku Band LNBF to my C Band bud. I climbed up on a ladder, and tried to find a signal that was 2 degrees west, and then east... Then 4 degrees, but never got a beep from my receiver.

Is this fool-hardy? Can anyone give me any tips? I have a fixed Cband dish, and would love to get Ku from satellites on either side of the prime focus.

Thanks.
 
I have seen it done where people would drill their scalar ring and affix a ku lnbf. I don't think it works very well being "off axis" on a prime focus dish. I would think you should get something. It may be that if your next to your scalar ring, you are more than 4 degrees off.

I would mount it someway and then bump your dish east and west and see if you lock any ku signals from neighboring sats.
 
Prime-focus dishes should do better than FTA offset dishes when going after off-axis signals. At 4 degrees off-axis you should only be down around 0.5 dB on gain. There could be several factors to consider:

1. What is the focal length of the dish? This will determine where 2 or 4 degrees off-axis is. It is very likely inside the scalar rings, maybe worse.

2. Some C-band dishes do horrible on Ku. Surface imperfections can make a big difference at higher frequencies.

3. Ku LNBFs are designed for high f/Ds. They will invariably under-illuminate a BUD.

4. I would use a meter for this kind of experiment instead of a receiver.
 
truckracer said:
I would mount it someway and then bump your dish east and west and see if you lock any ku signals from neighboring sats.
Click to expand...

That's an interesting idea, I could bump the dish 1/2 between two sats and then search for a 4 degree sat. If If I find one, that would let me know that a 4 degree sat lies inside the scalar ring.

So if 4 degrees is within the scalar ring area, is it futile to search further out? 6 degrees? 8 degrees? Or am I doomed if I try going that far out.
 
equant said:
I have a cheapy analog meter; the kind that come in the diy install kits with a crap compass. Would that be worth using?
Click to expand...

That should work just fine.

equant said:
So if 4 degrees is within the scalar ring area, is it futile to search further out? 6 degrees? 8 degrees? Or am I doomed if I try going that far out.
Click to expand...

Measure and post your focal length and we can calculate how far off-center 4 degrees will be. I don't see why you shouldn't be able to find signals well beyond 4 degrees, as long as the other points I raised are accounted for.
 
I have a ku lnbf mounted beside the feedhorn. It is mounted closer than the scalar and about 8 degrees off center. Works fairly well on 7.5' mesh dish. I can pull in RTV at 65 - 70 Q on a coolsat 4000 pro.
 
Status
Please reply by conversation.

Similar threads

Titanium LNBF Problem
Replies
12
Views
2K
LocutusOfBorg
Put a KU lnbf on my 8' SOLID Cband Dish
Replies
27
Views
4K
flody1
Trouble with Ku Signals on 10ft Mesh Bud
Replies
14
Views
2K
pacificrim
Testing the new Titanium C138 Performance Plus C Band LNBF
Replies
63
Views
11K
Titanium
P
Dallas area BUD looking for a good home.
Replies
0
Views
884
PdP
P
Menu
Log in
Register