[mythtv-users] OT: Wiring a new construction home for A/V, Ethernet, etc

[David Brodbeck]

On Wed, December 3, 2008 8:05 am, Allen Edwards wrote:
>>  > The other issue is grounds.  You want everything grounded to the same
>>  > reference point.

>>  > This goes for the TV antenna,
>>
>> That is pretty much impossible to achieve in practice, in part because
>> of
>> code issues.  In every jurisdiction I'm familiar with, a ground block is
>> required on the exterior of the building in the immediate vicinity of
>> where
>> the downlead enters the structure; and a dedicated ground MUST be run
>> from
>> this block by the most direct path possible, even if that means (as it
>> sometimes does) a separate copper rod in the dirt.

You can still effectively create a single-point ground by bonding the
ground rods together with a low-resistance conductor -- copper wire, say. 
Use a fairly heavy gauge, not so much for resistance reasons but because
it will be less likely to corrode through and fall off that way.

A single ground rod doesn't provide a very good RF or lightning ground, so
in serious antenna installations it's not uncommon to drive several rods
and bond them together.

> I was unaware you need a permit or an inspection to put up a TV
> antenna, btw.

In most places you don't.  HOWEVER, if you do a TV antenna installation
that's not up to code, and a lightning strike causes your house to burn
down, your homeowner's insurance may balk at paying up.