[Cialug] [OT] Digital TV

[Zachary Kotlarek]

On May 4, 2009, at 12:33 PM, <murraymckee at wellsfargo.com> <murraymckee at wellsfargo.com 
 > wrote:

> There is a 4 way splitter in the living room with one line going to  
> each of the two DTV boxes, one to the VCR, and one to the TV.


I am not a radio engineer, but my (non-DTV) experience fighting with a  
roof-mounted rotary UHF mast suggests that 4 legs without an amp is  
probably optimistic -- RG-6 has a loss of about 1 dB per 20 feet, and  
a 4-way splitter likely has a loss of 7-8 dB. You might consider  
replacing the splitter with a distribution amp or adding a pre-amp to  
the antenna feed.


> How does one ground the antenna so that lightening doesn’t get  
> transferred to the DTV box / VCR / TV etc.?


Start with a grounding block between the antenna and the entrance to  
your house -- a grounding block is essentially a female-female coax  
gender-changer where the shield is tied to a screw:
	http://www.sadoun.com/Sat/Products/Accessories/RECDSV70.jpg

Attach that screw to a standard ground rod (or other suitable  
grounding device) as close to the antenna as is practicable using a  
heavy gauge wire with no small-radius turns -- essentially the same  
procedure you'd use for a lightning rod. I believe the NEC always says  
you should connect the new ground rod to your breaker box, and I'm  
sure there are other rules about wire and antenna placement that you  
should follow if you want to do things right.

	Zach

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