c/ku band lnbf

[elmerqfudd]

due to the pbs shut down of their analog feed, we recently supplanted our toshiba analog c band receiver with an openbox s9 hd pvr digital receiver--though we still need to use the toshiba to rotate polarity (a 5v dc servo)

we would like to get a c/ku band lnbf----does anybody know how well these work? will we lose quality of reception?if there are tricks to getting the focus correct? if we can do away with the old analogue receiver for purposes of polariity change?
i have only seen 2 websites that sell c/ku band lnbf s
there is one at
The C Band LNB and C/Ku Band LNB BSC621 are now available today.
and the other is at
DMX741 C KU Band Prime Focus LNBF

are there better brands?

any information would be welcome

thank you

 

[Lak7]

I have used both the 621 and 741, and I prefer the 741.
My experience is that regular C Band feds they are about the same as a traditional C Band feed & LNB, but not as well on very weak feeds.
Ku is not as well as traditional Feed & LNB, but more of a convenience. IF they were as good as a "Polar Rotor" style setup, they would probably stop making them.

Patients is the Key when installing, a well aligned, good condition Dish too.

Polarity is Voltage Controlled, so no need for Analog Receiver for that. You will still need the Analog Receiver to move the Dish - unless you replace that with a GBox / VBox.

 

[Lone Gunman]

Tip, don't buy a DMX-741U as the Ku side of that thing will come back with funky numbers! The DMX-741S or Standard version is what you want. I've got both a polar rotor (Chaparral Corotor II) and an LNBF setup and I just love the LNBF because of it's simplicity. I like the one I have so much that I just bought another one and also another Vbox X to run my 10ft dish. Plan is to eliminate the GI920 and the polar rotor that I have connected to that dish now just to do polarity changes. We shall soon see how much signal I loose from the change.

 

[Anole]

one lizards observations...

The 621 came out a long time ago; it was first.
People had a lot of trouble with it, especially on Ku.

The CK-1 from SatelliteAV and the 741 from WSI/Galaxy came later.
Whether it was better understanding by the dealers & users, or a better product, both seemed superior to the 621, from what I've read.
There were so many people griping about the 621, I never even considered buying one!
I've since spent my money on both the Ck-1 and the 741.

There are several areas of concern for getting the latter two to do well on Ku.
Mostly, it comes down to moving the LNBF to the proper focal point, ...
... AND having the thing centered ON the dish, and pointed AT the center of the dish.
The more careful and detailed users have been able to get pretty good Ku performance.
Those who didn't understand the critical nature of Ku alignment, have struggled.

edit:
I think we have reviews of the Ck-1 and 741, in the Hardware Review department.
There have certainly been some excellent threads by users who installed them, discussing their efforts.
Linuxman and Stogie5150 come to mind right off, but there are many others.

 

[SatelliteAV]

R.I.P. CK1....... Satellite AV is no longer manufacturing the GEOSATpro CK1 LNBF. A recent change in component availability made it too costly to continue to produce the Standard LO version without a major investment in tooling.

BTW..... The GEOSATpro CK1 was the first combined C and KU band LNBF in North America. The 621 entered the market about 4 or 5 months later. Our development of the CK1 design with the factory engineers to optimize both C and KU bands combined with higher quality components are two reasons that this LNBF out performed the other brands, but this also made the CK1 more costly to manufacture.

 

[elmerqfudd]

thanks for your help, and one more question

thanks for all the input

i read the reviews and it sounds like the 741 will be the way to go


one question remaining
will i need a DiSEq switch at the dish in order to use just one coax back to the openbox receiver?
it looks like with the 621 a short pigtail from the ku band portion of the lnbf to the lower part of the lnbf eliminates the need for a DiSEq switch---am i correct in this, and if so, is true of the 741 as well?

 

[Lak7]

.....is true of the 741 as well?

The switch is inside the LNBF, but you don't "have" to use it, you can an external switch too.
Keep in mind the internal switch varies by Model- a "Standard Ku" unit uses a 22KHz Switch and a "Universal Ku" uses a Diseqc Switch.
I don't use the Internal Switch.