Twin LNB question
I recently set up a dish for a family member using a twin {dual) universal LNB with two RG6 coax going to two different decoders.
After a few days only one decoder was able to receive a signal so today I went over and removed one RG6 lead from the back of one decoder but on unscrewing the other end from the LNB I was getting a 12V tingle.
As a twin LNB is basically two lnbs stuck together I reasoned the LNB was dodgy so got a new one.
Long story short, the new one works fine but there was still a tingle when screwing the coax onto the second LNB F connector even though the other end was not attached to the second decoder at the time...why was I getting zapped? The other F connector was attached to a decoder at the time but I don't think any charge should be in the other connector as it is a separate LNB.
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Being universal, are you sure the two outputs are independent.eg: not one high and one low? (I'm assuming not as they are working on separate decoders).
It's possible the amp/downconverter is common to both outputs.
Either way, it's not a good practice to connect/disconnect LNB's with power supplied to them (or at the decoder end).
The common down converter makes sense.Originally Posted by mtv
The zapping occurred on the LNB F connector when it wasn't connected to a decoder... the other F connector was.
I had logically (to me anyway) thought there would therefore be no power on that F connector.
Last edited by mandc; 02-09-11 at 07:30 PM.
I think this is an opened view of a twin LNB and I can see what looks like sharing of the circuitry so you probably hit the nail on the head mtv...thanks for that.
So, can we mortals have a synopsis as to what that proves with your problem.
That it's probably the reason I got zapped on what I thought was a completely separate LNB....which was my question in post 1.So, can we mortals have a synopsis as to what that proves with your problem.
The problem I had was a dodgy universal LNB which was incidental to the question.
Last edited by mandc; 03-09-11 at 07:42 AM.
Did some more research and a universal must have 4 outputs for each one to be independent...a so called Universal Quattro Low H, Low V, High H and High V
which go into a multiswitch for multiple outputs
Which is why I asked about the configuration of the universal 'twin' and how it was working with two independent decoders.
Do you have it working now?
Yeah mate...all good after the new LNB went in
My LNB gives me little zaps when Im adjusting the focal point and skew.. Comes from the casing and my cables are secure.. I just use rubber gloves since dont want to be surprised and fall off ladder..
Zaps from casing not normal ?
Yeah, the zaps are normal but I got them from what I thought was an unpowered unused second LNB output on a twin LNB the first output being attached to a powered decoder.
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