The Natural Philosopher wrote:
On 10/06/2019 00:33, Dave W wrote:
On Sun, 9 Jun 2019 13:10:19 +0100, "Jim GM4DHJ ..."
wrote:

Just noticed I have lost all the horizontal channels on both satellite
rxs......is it as simple as a duff lnb or coupled with the fact I am getting
a shock off the outer of all the f connectors could it be a cable/plug fault
.....I get the shock with either rx switched on or both on so probably not
the rx.????...not got any test equipment here at the static van so probably
start with bringing down a new four way lnb the next time I come down ?
....if that doesn't cure it check all the cables for shorts? ....anybody had
this fault?...

According to Wikipedia, the LNB gets powered by 13V DC for vertical
polarisation and 18V DC for horizontal. The tingle you feel is due to
the receiver not being earthed, and some mains voltage is getting to
you via stray capacitance, hopefully not enough to harm you.

Something must be stopping the supply from getting to 18V, and I would
think it's your receiving device that's at fault, not the LNB(s).

It might be easier to try a different receiver before fiddling with
the LNB. You could earth the receiver metalwork to eliminate those
unpleasant shocks.

A lot of unearathed metalwork floats at 110vAC due to there being RF
filter caps to live and neutral from the metal case.


It shouldnt be designed like that, it is pointless. It doubles the Z
between L&N to dump noise via the Cs (Cs in series rule) and introducing
the stray 110Vac point. As I posted in another group, this situation can
arise due to a fault condition if, for example, the earth at the plug (top)
is lost or somewhere else before the filter.


Whilts not a hazard, you can definitely feel this and its capable of
blowing circuitry that is earthed if connected to it.


Again, it could explain the shock and the failure. Jim would be wise to
rule it out before sticking a new lnb in. Even if it works initially, it
could fail later and hes back to square one, missing Love Island ;-)





--
Corbyn & the EU, the Nazis next step: "Our aim was Europe a nation. Our
faith European Socialism" Mosley "My Life" autobiography 1957.