Stack Two KU Dishes?

[Indy]

OK, got the dish and the LNB, & star bracket from Galaxy. The LNB sent is a Power Sat model PS41-1075. Is this a good choice for my 6' Prime Focus KU dish? Are there better LNB's for just KU? Or,what model LNB for C and KU combination would one suggest? I would not like to sacrifice KU performance to do both KU and C band. I also purchased a Chaparral model 409008712 universal KU LNB and I have a couple of Primestar dishes with Eagle Aspen KU LNB's using the old Primestar feed horns. Suggestions? Thanks

Here is a link to the Chaparral, I did not find it on their site.
Chaparral Single HD Ku Band LNB Steel Housing(FTA) LNBF - eBay (item 220580557961 end time May-23-11 00:16:56 PDT)

 

[Anole]

OK, got the dish and the LNB, & star bracket from Galaxy.
The LNB sent is a Power Sat model PS41-1075.

Found it with Google searching on PS41-1075.

Is this a good choice for my 6' Prime Focus KU dish?

Nope, not at all. Doesn't have the F/D to see the entire dish.

Are there better LNB's for just KU?

Yes, see my post above.

Or,what model LNB for C and KU combination would one suggest?

Probably none; see my post above.

I would not like to sacrifice KU performance to do both KU and C band.

That's what you said, so that's why I recommended the right stuff.

I also purchased a Chaparral model 409008712 universal KU LNB...

Looks like just another Universal LNBF for an offset dish.
Nothing wrong with it, but not related to use on a prime focus dish.

... and I have a couple of Primestar dishes with Eagle Aspen KU LNB's using the old Primestar feed horns.
Suggestions? Thanks

Only what I posted above. -

 

[Indy]

Anole, I realize you have had to hit me over the head more than once. Is this the KU LNB I need to order?
LNB'S - DMSI - products new home - BSC321SP Prime Focus Ku kit

 

[dougruss]

Anole, I realize you have had to hit me over the head more than once. Is this the KU LNB I need to order?
LNB'S - DMSI - products new home - BSC321SP Prime Focus Ku kit

This is the LNB you want....... :Satellite AV, LLC - Satellite Broadcaster Support and Equipment Distribution

 

[Indy]

Doug, Thanks for the reply. I am pulling the trigger on the one you recomend. I see it has the ring type feedhorn.

 

[Anole]

Yep, that one at SatelliteAV would be (and has been) my first choice.
Buy it, and be happy! :up

However, to answer your question, the BSC321sp is $13 at IvyStonePlace.com, as recommended above when I thought SatAV was out of stock. Not the $36 ya found for the same LNB with a $5 bracket.

 

[phlatwound]

This is the LNB you want....... :Satellite AV, LLC - Satellite Broadcaster Support and Equipment Distribution

I have never understood why that LNBF (with a specced F/D ratio of 0.5 - 0.7) is recommended for prime focus dishes that typically have F/D ratios of around 0.3 -0.4....what am I missing here?

 

[Wescopc]

I have never understood why that LNBF (with a specced F/D ratio of 0.5 - 0.7) is recommended for prime focus dishes that typically have F/D ratios of around 0.3 -0.4....what am I missing here?

I have wondered about that as well - perhaps SatelliteAV could weigh in on this....
Bob

 

[Indy]

Originally Posted by phlatwound
I have never understood why that LNBF (with a specced F/D ratio of 0.5 - 0.7) is recommended for prime focus dishes that typically have F/D ratios of around 0.3 -0.4....what am I missing here?

The specs for the dish I purchased has a F/D ratio of 0.38

 

[Indy]

Now I am confused. The prime focus dish I purchased has a FD ratio of 0.38. The SL1P - GEOSATpro LNB has a FD ratio of 0.5-0.7. The BSC321SP LNB does not state the ratio in the specs. At least I have not seen the figure anywhere. Anyone know the ratio of the BSC321SP? Should I purchase this one too and choose the best one based on performance?

 

[Indy]

I found a really good thread where Iceberg compares 3 LNB's on a Primefocus 6' dish. Looks like the GEOSATpro SL1P is the best choice.

http://www.satelliteguys.us/free-air-fta-discussion/181927-bsc321sp-f-d-ratio.html

 

[SatelliteAV]

I have never understood why that LNBF (with a specced F/D ratio of 0.5 - 0.7) is recommended for prime focus dishes that typically have F/D ratios of around 0.3 -0.4....what am I missing here?

The GEOSATpro SL1P scalar is designed for prime focus design dishes and even though there is a mismatch on the FD, the mechanics and electronic performance exceeds all other LNBFs when mounted on a prime focus dish. We were aware of the issue when we authorized the manufacturing of this OEM product, but had tested it thoroughly and knew that it performed better than any other combinations. Instead of hiding the specification for the FD we let the buyer know what they are buying, but are confident in the knowledge that it outperforms all other available KU band LNBFs for prime focus applications.

 

[Indy]

Brian, This is reassuring to me that the right choice has been made. One question to installation. Is the focal length of the dish to the outer surface of the feed horn rings or to the throat of the LNB behind the rings?

 

[phlatwound]

The GEOSATpro SL1P scalar is designed for prime focus design dishes and even though there is a mismatch on the FD, the mechanics and electronic performance exceeds all other LNBFs when mounted on a prime focus dish. We were aware of the issue when we authorized the manufacturing of this OEM product, but had tested it thoroughly and knew that it performed better than any other combinations. Instead of hiding the specification for the FD we let the buyer know what they are buying, but are confident in the knowledge that it outperforms all other available KU band LNBFs for prime focus applications.

Thanks for that explanation Brian, appreciated, sounds like it should perform well for Indy.

I bought a couple of those from you a couple years ago, haven't had a chance to try them out on a prime focus dish yet, but can report it worked well on a .9 meter offset.

 

[Mr Tony]

The SatelliteAV LNB kicks butt on my 6 foot dish. Have used it a few times when my 36" dish wouldnt keep the feed stable (or in the case of 116.8 KU) allow the signal to be shown (I;'m on the fringe of the footprint)

 

[Indy]

The SatelliteAV LNB kicks butt on my 6 foot dish. Have used it a few times when my 36" dish wouldnt keep the feed stable (or in the case of 116.8 KU) allow the signal to be shown (I;'m on the fringe of the footprint)

Ice, you really did a through comparison a couple of years ago on the GEOSATpro SL1P LNB. We all thank for the time you invested testing the different LNB's. I do have a simple question I posted above but did not receive an answer. From what point on the dish face, I assume dead center, and what point on the LNB is the dish focal point supposed to hit? The front of the LNB feed horn rings or further back into the LNB?

 

[Mr Tony]

I dont understand what you're asking.

I have a special bracket to hold the LNB in. I dont know if SatAv sells them but Galaxy does
WSC2KU C band to Ku Band Satellite Dish Conversion Bracket | LNB Mount LNBF Holder

The bracket bolts to the arms on the dish and the LNB fits right inside of it. I dont know what would happen if you kept the original C-Band scaler ring on there.....hmmm....maybe an idea?

 

[Anole]

Just like on an offset Ku dish, ya need to move the feed/LNBF closer to the dish, and away a little, looking for best Quality on a weak signal.
I think Iceberg commented on that adjustment in his review.

As for mounting in the hole of the C-band scalar, the body of the SatAV LNBF might bump the backside before reaching the best tuning point.
I recall seeing someone (ACradio?) mount an Invacom Ku feed through the hole, but don't remember how he grabbed onto the feed or body of the LNB.
The scalars are frequency sensitive, so I doubt the presence of the C-scalar would have any effect.

 

[Indy]

Ice, I already have the same bracket you use with the Prime Focus. What I was referring to on the SL1P LNB is,the LNB appears to have scalar rings. See the link, are we still talking about the same LNB?

Satellite AV, LLC - Satellite Broadcaster Support and Equipment Distribution

 

[Mr Tony]

yep thats the same LNB I have

I put it in the bracket and push it in 1/2" to 3/4" towards the dish for optimum signal....but your milage may vary