Should you earth a dish?

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As the title says... should you earth a dish?

In the US codes exist that you have to earth a dish in a garden with a separate ground earthing spike on the steel work & outer cable shield.

In the UK only shared dishes and shared TTV systems require bonding, but single property dishes don't actually require an earth.

The issues aren't regarding safety - (although that is another important issue). It's regarding reducing noise / interference on weak satellites and/or causing signal loss (or not) by earthing and the trade off and the aspects of receivers not being earthed either.


What do you think?
 
Hi pedro, does this mean that interference can be reduced by earthing ??

i,ve never heard this discussed before ?if it was the case wouldn,t it be

common practice to earth every antenna ??, a very interesting idea

though.:confused::confused:

regards Dave
 
You have to remember that a dish is not an antenna!
Earthing an antenna (or rather the counterpoise / groundplane) would depend on whether the antenna is a balanced modulator - or designed to be earthed.
When earthing it's also worth considering that a short circuit is in effect an anti-phase open circuit!
 
4dbennett.....Hi pedro, does this mean that interference can be reduced by earthing ??
i,ve never heard this discussed before ?if it was the case wouldn,t it be
common practice to earth every antenna ??, a very interesting idea
though
Click to expand...



That's really why I'm trying to get different member's experience..

Certainly in high noise areas it could help - but also dropping to earth could also draw down some wanted signals.

It could be the other way round in some circumstances insulating from earth ground.

btw.. A dish on a pole doesn't usually connect the outer cable shielding and thus the common chassis ground to the steelwork & metal dishes. Fitting a motor then does via its f connectors. Poles in the ground may ground anyway to a degree especially in wet weather.
 
You have to remember that a dish is not an antenna!
Earthing an antenna (or rather the counterpoise / groundplane) would depend on whether the antenna is a balanced modulator - or designed to be earthed.
When earthing it's also worth considering that a short circuit is in effect an anti-phase open circuit!
Click to expand...

I think it's safe to say most on here know a dish is a reflector, not an antenna*, but it is capable of being an antenna along with anything metal-ish.... like the steelwork, LNB casing, cable outer (and inner), stb case and components & pcb in the stb & lnb .. that's what this is about.

On balance then what is your actual conclusion?








*actually.. the government don't if you've ever looked at planning laws ...:)
 
IMO it depends upon the installation. Some will benefit, some will not. If one dish is serving two buildings for example that have different earthing systems then this can introduce a whole host of problems, particularly if one system is 'leaky' or if there is a PD between the two. You may also find that the effects on installations in the Middle East are vastly different to the effects on installations in typical European countries. You might also find that changing the length of the earthing cable has an effect.
 
earting dish itself caused no signal changes at all for me. earthing also LNB - caused 50hz hum and vertical blinds on tv screen. and killed upper band (above 11700mhz).
 
I grounded it to 3rd - grounding wire in electric outlet. When I connected outer of lnb cable to it, there was quite noticeable small spark. Hovever, with voltmeter I was not able to identify any voltage. So I connected various light bulbs into that circuit. 12V 5W one shined quite nicely :)
 
That would indicate a fault that is being highlighted by earthing.... 'somewhere' on the media system or electrical system and really should be checked out properly.

As a safety note to anyone:

Please note, this thread isn't intended to encourage anyone to experiment with earthing etc. It all sounds safe etc... but before earthing anything, a number of basic checks have to be performed ...mainly to ensure there isn't a fault on any of the connected equipment that earthing could reveal and their suitability and the choice & nature of earthing or grounding (copper ground spike etc).
 
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