Question Wideband LNB with long cable run

jonniewotsit

Novice Member
Hi, i need some technical help please.
I have a 80cm dish with a universal wideband LNB fitted on a garage for skyQ.
The garage is about 120m away from the house and has two WF125 cables (V & H) buried in the ground in conduit to the house.
I'm getting some intermittent picture breakup on a few sky movies channels that i'd like to fix.
Signal checked on a friends spectrum analyser, getting about 63db on both polarity’s in the house with good MER.
I’ve tried fitting some johansson inline wideband I.F amps at the house end, but that’s just seems to make lots of channels pixelate and is much worse.
Wondered if you have any suggestions please? It's not possible to relocate the dish nearer to the house, or replace with a fibre cable run.
I've heard over this distance using wideband LNB’s can cause problems due to the higher frequencies used. The skew of the LNB has been peaked to it's optimum as well.
I do have mains power at the garage as well if required, but the whole cable run is buried so can’t fit anything inline midway.
TIA
 

jonoro

Active Member
The place to fit inline amplifiers is before the signal loss never after it. Fitting them at the house end is pointless unless they have a better S/N ratio than the Sky box front end. Thimn masthead amplifiers, why do you think they are at the aerial end rather than next to the receiver?
You could find the specification of the cable used, calculate its loss and then pick "better" cable, i.e. lower loss and see how much extra signal you would get if you replaced the cable. This way the extra signal comes noise-free, adding the inline amplifier adds noise too.
 

jonniewotsit

Novice Member
ok thanks,
maybe i'll try the inline amps at the dish end then.
It's good quality webro coaxial cable, WF125 the thick stuff for long cable runs, not the standard type WF100 7mm. It's not possible to replace the cable. If i could i would now use fibre.
 

Phantom84

Active Member
What sort of connectors do you have on the end of the cables? If its standard screw on ftype look at replacing with compression fittings.
 

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