Extreme LNB and primestar

[9999]

What is the best way to mount an extreme LNB on a primestar? I have 3 of those mast brackets at different sizes and none fit. I guees I'll try bending a piece of metal and custom drilling the screww holes.

 

[Das Hammer]

Nylon wire ties. Duct tape.

There are a lot of these dishes around here that have been retro-fitted with LNBF's for directv. The "face" of the new LNBF is just mated with the "holder" on the primestar dish then taped up or tied up. Just make sure the new LNBF is in close proximity to where the original one was. You want to try and maintain the optimum distance from the dish (focal depth).

 

[9999]

thanks. might try the wire ties first.

 

[Das Hammer]

Was your primestar dish missing the lnb and feedhorn, or did you just want to start out with a newer, better lnbf?

Just curious as I am fixing to put one of these up in the next two weeks to complement my 10 footer.

 

[9999]

It had one. I want to improve my reception. I have heard that some people have gotten a 20-30 point improvement in sig quality.

 

[Mr Tony]

The Primestar LNB's were a .7 or a .6
The Xtreme is a .3 so it will help

Was the Primestar LNB the one with 2 separate outputs for V & H or one?

 

[Das Hammer]

It had one. I want to improve my reception. I have heard that some people have gotten a 20-30 point improvement in sig quality.

I'll probably go that route too. Was looking at the Invacom with the C120 mount so I could keep the same feedhorn. Got an Eagle Aspen 3x4 multiswitch that I'm going to use for the time being.

 

[9999]

It had the V and H. Tried the extreme and saw no noticeable improvement. It was getting dark so I swithched back to the P*. Maybe this weekend if I have time I will take a tv outside and try to peak the extreme.

The Primestar LNB's were a .7 or a .6
The Xtreme is a .3 so it will help

Was the Primestar LNB the one with 2 separate outputs for V & H or one?

 

[MikeI]

How did you get the Xtreme to fit? Did you use the ties?

 

[Stats8]

If you have a 40mm neck on the lnbf and you want to keep the plastic housing around it, the old Primestar bracket can be modified fairly easy to hold the lnbf.

See pic.

 

[9999]

If you have a 40mm neck on the lnbf and you want to keep the plastic housing around it, the old Primestar bracket can be modified fairly easy to hold the lnbf.

See pic.


View attachment 8042

What lnbf is this? I guess what I was asking was, did most people make the clamp themselves or is there a particular one already made that would fit.

 

[9999]

How did you get the Xtreme to fit? Did you use the ties?

I used one wire tie. I guess that would hold it permanetly but I removed it. I will try it again this weekend to see if I can peak it. On my trial, I got no gain in quality.

 

[Mr Tony]

What lnbf is this? I guess what I was asking was, did most people make the clamp themselves or is there a particular one already made that would fit.

That is a Fortec LNB...standard 40mm throat on it

I know they have clamps like that at gardware stores.

 

[Stats8]

The type of lnbf does not matter, its the diameter of the neck that does.
If you strip the plastic housing of the lnb, you will have a 20mm neck that
can be mounted in the Primestar bracket with almost no modification since
the bracket is meant for 20mm.

First pic, this is a dual bracket with a stripped lnbf, brand does not matter.

Second pic shows a Primestar bracket routed out to 40mm, so you can mount your lnbf, with the housing on, I suppose it does offer some weather protection this way.

Ice, the metal hold down is just a piece of band steel with a hole drilled in it.

 

[bryansr]

I have taken PVC pipe and cut it down for fillers for LNB's that are too small also.

BryanSR

 

[drhydro]

One thing about the original oval p* lnb's is that they are high stability units, even if by todays standards they have a high noise rating. Also the feedhorns on the oval units are designed to gather the maximum amount of signal from the dish, which aftermarket lnbf's wont do.

 

[Stats8]

DrHydro, the scalar ring on the primestar lnbf does seem to be optimized for the oval dish.
As far as performance of an original primestar lnbf and a modern low noise lnbf, I have not seen test comparing the 2.
I am in the beginning stages of setting up a 40x30 primestar dish with a sg2100 motor and a QPH-031 lnbf.
Problem is it will need a 10' tower due to location, but I will test both type of lnbf when ready and report here with the results.

 

[ftarock]

It's a bit sad when seeing buyers are trapped by the marketing hype of noise figure. A .3 noise lnbf with bad stability is worse than a 1.0 with good stability measurement.
Take at look at ku lnb that made commercially (Norsat as an example), none of them are measured at .3
A Norsat 1.0 High Stability beats a hell of of ANY 0.3 lnbfs any day in any condition!!!
Unfortunatly none of the Ku lnbfs come close to the Ku lnb.
FtaRock

One thing about the original oval p* lnb's is that they are high stability units, even if by todays standards they have a high noise rating. Also the feedhorns on the oval units are designed to gather the maximum amount of signal from the dish, which aftermarket lnbf's wont do.

 

[WyrTwister]

I have taken PVC pipe and cut it down for fillers for LNB's that are too small also.

BryanSR

I called them spacers , but , yes , I have done the same thing .

Wyr

 

[Stefan]

A .3 noise lnbf with bad stability is worse than a 1.0 with good stability measurement.

And the LO stability rating of those invacoms is like +- 1.0Mhz. That's horrible compared to any modern day commerical type LNB.

Another thing to keep in mind is there has to be some point of diminishing return with regard to noise figure. By this I mean there's got to be some point where the noise your dish picks up from adjacent satellites, space, and terrestrial interference (especially if the scaller ring isn't properly adjusted or the feedhorn isn't properly illuminating the dish) are going to be greater than the noise introduced by the LNB. This leads me to the conclusion that it's better to go with a larger dish and higher stability LNB than to worry much about noise figure ratings of an LNB.