PrimeStar LNB vs QPH-031

[gabshere]

ok i received my newer primestar (DirecPc) lnb's today and retrofitted my old feedhorn from the old primestar round 1m dish. i have a QPH-031 currently mounted on it and took a few signal readings to compare now..... for those of you who don't know the QPH-031 is mounted but i don't feel that i've got it peaked because the plastic housing is hitting the lnb bracket mount (i could remove the plastic housing off the lnb and test it but i haven't yet). will try to take a photo in the daylight.

ok some more information the old primestar lnb's that i had were the two output type one for H and one for V , so i found a deal on some more single output lnb's i converted a few to fit this type dish. photos below.
the photos are: new retrofited (DirecPc) lnb's , the backs, new lnb front & back , old type dual output (H&V) lnb

you might be suprised by the results (next post).

both the old Primestar LNB & Newer DirecPc LNB I used are made by Hughes.

 

[gabshere]

ok this comparison was done with a 1m (40X44in) Dish , Coolsat 5000 & SG2100 motor

i picked common tp's which i think all are listed on lyngsat

SAT / TP QPH-031 Primestar (new retrofit) lnb
AMC 4 101
11706V 76% lev 97 SQ 76% lev 93-94% SQ
12120V 89% lev 87-88% SQ 86% lev 66% SQ
11833H 81% lev 97% SQ 83% lev 97% SQ

GALAXY 25 97W
11835V 86-87% lev 93-94% SQ 90% lev 91-94% SQ
12083V 89% lev 91% SQ 87% lev 89-91% SQ
12175V 89% lev 94-97 SQ 87% lev 94% SQ

GALAXY 26 93W
11709V 81% lev 93-94% SQ 83% lev 93-94% SQ

GALAXY 11 91W
12059V 85% lev 66-67% SQ 85% lev 87-90% SQ

Galaxy 28 89W
11954V 83% lev 90-91 SQ 85% lev 94-97% SQ

AMC 3 87W
11715H 76% lev 97% SQ 81% lev 97-98% SQ
11735V 76% lev 87% SQ 79% lev 91-94% SQ
12164H 75% lev 90-91% SQ 76% lev 87-88% SQ
12179V 81% lev 66% SQ 82% lev 87-88% SQ

AMC 2 85W
12196H 75% lev 87-90% SQ 72% lev 90-91% SQ

AMC 5 79W
11741V 78% lev 90-91% SQ 82% lev 93-94% SQ
12180H 82% lev 91-92% SQ 81% lev 87-88% SQ

SBS 6 74W
11741H 78% lev 97% SQ 81% lev 97-98% SQ

ok i think it was close ... now the QPH seems stable and it might pick up a few points when i get it properly focused ( or the proper focal distance). But it suprised me at how close the new primestar lnb performed. it even did a real good job on the PBS channels i usually have trouble picking up cause they are close to the threshold for my coolsat......

next test hopefully soon will be with my primestar oval

 

[Anole]

Somebody needs to loan you a flange-mount Invacom to make an even more interesting test! :up

 

[turbosat]

That was a question I was pondering today>what would be a good replacement lnb for primestar dishes, since Im using 3 of those old dishes now......
Where do you get replacement Hughes lnbs tho??

 

[Tron]

The P* LNB probably performed as well as it did because it is using the feedhorn designed for the dish. My .9 NF Norsat PLL sometimes OUTPERFORMS the Invacom (but they're very close). The Norsat is mounted on the proper feedhorn for the dish, and is also a high L.O. stability LNB.

 

[gabshere]

found them on ebay for a good price

yes i beleive the original feedhorn hits the sweet spot better than the QPH

would like to try the flange mount one or i guess i can remove the case on this one.

 

[dem0nlord]

FYI, those are DirecPC LNBs.

 

[SatelliteAV]

Buy a QPF-031 and mount it on the Primestar feed horn. The best of both worlds!

 

[turbosat]

Thanks DL I HAVE a direcpc dish but haven't totally taken it apart. I had thought about using it on another dish though, because it has the switch built-in. A new project !!

 

[stogie5150]

Buy a QPF-031 and mount it on the Primestar feed horn. The best of both worlds!

Brian, maybe you can answer this..why is the QPF so danged much more expensive than the QPH? I picked up a QPH for 59.00 shipped a couple weeks ago...I haven't found a QPF for under 100.00 shipped...I'd like to have a QPF for my 1m P* dish...but dang, not for DOUBLE the price....

 

[SatelliteAV]

The quantity produced affects the wholesale cost dramtically. I would be surprised if more than a few hundred units of the QPF have been sold.

 

[gabshere]

yes i believe it is a DirecPc LNB , but i just termed it a new primestar lnb ( allthough it isn't) lol it was a perfect fit.

still trying to trace down a QPF for testing and i would probably sell my QPH if i found one ..

 

[nsaspook]

Buy a QPF-031 and mount it on the Primestar feed horn. The best of both worlds!

Works fine with the oval dish feedhorn.

 

[Anole]

...I would be surprised if more than a few hundred units of the QPF have been sold.

If I find some big surplus dishes with horns, and I'll pop for the Invacom flange mount.
Just seems (subject to test) like the right way to go.

 

[gabshere]

I will go back and edit my first post to reflect it to be a DirecPc lnb and i will put one of the original lnb's back on and get a few numbers ..... and also i hope to fine a reasonable OPF-031 there are two other flang type from invacom but for the price i don't think i would consider adding them to the test .

then the next test will be to mount a oval Primstar dish and take some numbers.

as of last night i removed my QPH-031 and placed the DirectPc retrofitted lnb back on cause it receives PBS 20% SQ better for some reason.plus i would like to test it throught the day to see if the signals change.

 

[mastermesh]

20% gain in PBS Channels. That's a good move. If I did it all over again, I'd probably put the primestar on a motor, but it's too late now because the winegard's getting the arc pretty good, and it's taken a lot of time to get it to the point that it does get the arc as well as it does now.

 

[ChuckBoozer]

Buy a QPF-031 and mount it on the Primestar feed horn. The best of both worlds!

Will this set-up allow you to skew the LNB?

 

[gabshere]

some of the feedhorns allow for skewing. some were solid one piece feedhorns (this deals with eliptical) .....since the one you had was the dove bar type primestar lnb and i think you said it was skewable. then if you mated it (the feedhorn) up to the QPF it would be skewable.

i will post pic of the different ones i have later , i'm not home right now. all the round 1 meter primestars i've seen are skewable.

 

[Stefan]

as of last night i removed my QPH-031 and placed the DirectPc retrofitted lnb back on cause it receives PBS 20% SQ better for some reason.

Is the PBS signal your refering to a "thin" signal? By "thin" I mean does it have a low symbol rate. If so, that's likely an indication that the directPC LNB probably has a much better LO stability as this seems to be much more important on low symbol rate signals. If I remember correctly the LO stability on the invacoms is not rated that well. Ideally a PLL lnb would be the best for most signals with low symbol rates.

I'd be interested to see how the original NJR LNBs compare to both the DirectPC and Invacoms. I wouldn't be too surprised if they performed quite a bit better than you might expect.

 

[gabshere]

i will have to check that out and post when i get home . i think the main downfall for the QPH is that it won't adjust properly (it hits the lip of the lnb and won't adjust fd properly) i think the QPF will. Several of us primestar owners are getting together soon and are going to test several lnb's with the primestars. i would like to hook up a good norsat lnb and give it a try ....