LNB question

B

bkl_tek

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#1
I'm about to change LNB. The current LNB has a ridge on the collar so it can not move forwards and backwards. The new LNB has no marking or ridge on the collar, so the question is does the distance from the dish to the tip of the LNB make a difference? The new LNB (MTI blueline) would be able to move backwards and forwards about 50mm within the LNB holder.
Thanks in advance for any help.
Barry
 
rolfw

rolfw

Believe it when I see it Admin.
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My Satellite Setup
Technomate 5402 HD M2 Ci, DM7000s, Transparent 80cm Dish, Moteck SG2100 DiseqC motor, lots of legacy gear. Meters: Satlook Digital NIT, Promax HD Ranger+ spectrum analyser.
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Berkshire
#2
You should notice a small difference in the signal strength and quality between the two extreme positions Barry, so it is, like adjusting skew a little bit of trial and error.
 
Channel Hopper

Channel Hopper

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A little less analogue, and a lot more crap.
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#4
On quality dishes the feed is separate to the LNB and is matched to the shape of the antenna. In this case there is a defined distance to the dish

On LNBs that have integral feeds the feedhorn is a compromise to allow reasonable illumination of a large number of dish sizes. The focal point remains the same, but the need to move the LNB in and out gives you a trade off between efficiency of the feed and the illumination of the dish.

Without knowing what dish you have its not possible to give a beeter idea as to the degree of success
 
B

bkl_tek

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#5
The dish is an 80cm offset aluminium grey mesh dish. I can't remember the make as I bought it about 4 or 5 years ago. I'll have a look tonight to see if there is any markings on the dish to identify it. The LNB is an MTI blueline 0.6db universal LNB (just takes the coax and no other connections).
Barry
 
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