Dish earth?

"R. Mark Clayton" wrote in message
...

"amp is" wrote in message
...
Earthing is required when multi output LNBs feed different properties.
Adjacent properties may be on different mains phases and if the
insulation breaks down on a STB in one house it could find it's way
through to the other houses connected to it.



Well it is more exciting than that because often boxes are isolated and
the chassis (and cable shield) drift up to about 120V AC. Not a lot of
current, but a worrying tingle when you are forty foot up and not
following the "working at heights directive" 100% (or even if you are I
suspect).


"Trevor" wrote in message
...
Hi

I have fitted a satellite dish for Freesat which is working fine. I did
notice that there is provision for an earth connection to the dish but
looking at local Sky fitted dishes they don't seem to bother to earth
them.

Should I bother to earth mine?

Trevor

Worth mentioning that Sky's original Amstrad DRX200 was earthed.
A conscious decision must have been taken to go for double insulation.

I can see no reason why the DRX200 wouldn't have been approved
without the earth.

I think those slim Sony boxes were earthed too IIRC
Of course there is always the possibility that any box could
end up earthed via other equipment.
--
Graham.

%Profound_observation%

Hi

"andrew fox" wrote in message
news
Trevor wrote:
Hi

I have fitted a satellite dish for Freesat which is working fine. I did
notice that there is provision for an earth connection to the dish but
looking at local Sky fitted dishes they don't seem to bother to earth
them.

Should I bother to earth mine?

Trevor



are we talking like lightening rod here?

There is just the symbol for earth with a nut and bolt to fix it to,
I assume to a water pipe in the house?

The dish is a Raven 80 and I have fitted a quad LNB to it.

"Trevor" wrote in message
...
Hi
are we talking like lightening rod here?

There is just the symbol for earth with a nut and bolt to fix it to,
I assume to a water pipe in the house?

The dish is a Raven 80 and I have fitted a quad LNB to it.

No, forget it for a one dwelling domestic install.

Bill

"amp is" wrote in message
...
Earthing is required when multi output LNBs feed different properties.
Adjacent properties may be on different mains phases and if the insulation
breaks down on a STB in one house it could find it's way through to the
other houses connected to it.

Eathing the dish metalwork is nowt to do with the regs re multi-dwelling
installs, because the LNB feeds are isolated from the metalwork.

Bill

On Sun, 12 Oct 2008 16:47:12 +0100, Chas Gill
wrote:

I'm probably showing my ignorance here (having just returned form a very
convivial hour or two in the local hostelry), but if the dish is earthed
surely all the (minute) RF that it collects from the satellite will be
diverted to earth rather than reflected to the LNB - thus effectively
defeating the entire point of a reflective collector?

If I connect my mirror to earth, will it reflect the light or just show me
black?

In article , Paul Ratcliffe
wrote:
On Sun, 12 Oct 2008 16:47:12 +0100, Chas Gill
wrote:

I'm probably showing my ignorance here (having just returned form a
very convivial hour or two in the local hostelry), but if the dish is
earthed surely all the (minute) RF that it collects from the
satellite will be diverted to earth rather than reflected to the LNB
- thus effectively defeating the entire point of a reflective
collector?

If I connect my mirror to earth, will it reflect the light or just show
me black?

What frequency did you have in mind? :-)

Slainte,

Jim

--
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In article , Graham.
wrote:


No no. They don't even need to be electrically conductive.
http://www.satellitesuperstore.com/clearmenu.htm

Oh yes they do - conduction is part of the reflection process -
transparent does not mean non-conductive.

I am sure you are right in the sense that a material may be conductive
on the molecular level and be a total insulator for practical purpose of
passing any current.

FWIW You can make highly effective reflectors using dielectric. Indeed, the
high reflectivity mirrors used for some lasers employ what are called
'dielectric stack' mirrors. These exploit the reflectivity of (mutliple)
dielectic surfaces/interfaces. This avoids the conduction losses of normal
metals.

However I doubt many sat TV dishes use this technique. :-)

Slainte

Jim

--
Change 'noise' to 'jcgl' if you wish to email me.
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What would be the point in earthing it?
Brian

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"Adrian" wrote in message
om...
Trevor wrote:
Hi

I have fitted a satellite dish for Freesat which is working fine.
I did notice that there is provision for an earth connection to
the dish but looking at local Sky fitted dishes they don't seem
to bother to earth them.

Should I bother to earth mine?

Trevor

I've never seen one that is earthed.

"Trevor" wrote in message
...
Hi

I have fitted a satellite dish for Freesat which is working fine. I did
notice that there is provision for an earth connection to the dish but
looking at local Sky fitted dishes they don't seem to bother to earth
them.

Should I bother to earth mine?

Trevor



Well the installation instructions for the Humax Foxsat say on page GB3


9. EARTHING
.. The LNB cable must be earthed to the system earth for the satellite dish.


AIUI no one bothers with dish earths in the UK but there are some counties
where a dish earth is compulsory.

When I installed by satellite dish I did get a shock from the LNB cable
screening when working outside. The shock came from the TV to which my
satellite receiver was connected.


--
Michael Chare

In article ,
Michael Chare wrote:

AIUI no one bothers with dish earths in the UK but there are some counties
where a dish earth is compulsory.

Do you mean "some countries"?

-- Richard
--
Please remember to mention me / in tapes you leave behind.