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Discussion Starter · #1 ·
I'm getting a new dish by channel master, called the

gain-master... a triple-beam dbs antenna (75cm).


Can anyone recommend a good quality LNBF.

I don't know where to look, or what to look for.


Should I buy the same lnbf for 101,110 and 119 ?

What company makes good LNBFs ?


Thanks

Matthew
 

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There are (ONLY?) two manufactures of LNB's for DBS, California Amplifier and Grundig. They OEM for everyone. They differ mainly in cosmetics of the plastic. the Grundig has a thicker appearing pastic shell that give the illusion of a shorter neck. Both offer single or dual amps.


The Sat C LNB is a single amp with a differant Local Oscillator frequency to allow its output to be combined through a Low Pass filter to the Sat B signal.


Grundig is currently in the news as being on the edge of going out of business.
 

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What a golden opportunity for Rupert Murdoch to step in as a "knight-in-shining-armor". :D
 

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Discussion Starter · #5 ·
I can't find good LNBs for directtv here in the usa.

All the quality ones seem to be made in europe for

satallite tv there.


Still looking for a site with some info and specs on lnbs.


Matthew
 

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What are you calling a "good" LNB? Why do you believe that the ones you have described as having been made in Europe for satellite TV there are any better than the ones available here? Does Europe even use circularly polarized signal for their Direct Broadcast Satellite services?


I have seen no indication that any DBS LNB is any better than any other. The published specs for gain, noise, and cross polarization rejection of United States domestic, 12.2Gz - 12.7Gz circularly polarized LNBFs are all virtually the same.


About six years ago, DISH Network was badmouthing Grundig LNBs for a short time. I never found out if there was any substance to that criticism, but that is now old news.
 

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To my knowledge, DIRECTV's transmission is in horizontal and vertical polarization. The cross polarization from H to V is 30 dB down. My favorite triple LNB Multi-Satellite LNB/switch integrated head unit is made by Acer.
 

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DirecTV's signals are circularly polarized. The orientations, "horizontal" and "vertical" apply to linearly polarized signals. The polarization of DirecTV's signals are alternately "left-handed" and "right-handed".


The only published cross-polarizatiion rejection figure I have ever seen for circularly polarized, DBS LNBs is 25dB down. If anyone can find a different published figure, I probably would tend to ignore it unless it was accompanied by a plausible explanation of why it was greater than that of competing LNBFs. A cross polarization spec of 30dB down is common for linear LNBFs.


In any event, the magnitude of cross polarization interference at 25dB down is already so far below the noise floor of a DBS signal as it comes out of the LNB that further improving it would be of no perceptible consequence.
 
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