Re: [A/S] Setting up a Sat. Dish

[Rick Kunath <k9ao@xxxxxxxxxxx>]

> No.  The satellite needs its own connection.  What I did was buy a flat
> co-ax piece, about 8" long and I ran it though the window.  The window
> closed on it and I brought it through the screen fuzzies where the lift
> handles were. I'm not sure how the Safari windows open, but the flat coax
> is the way to go. Then you'll need coax inside to the tv and coax outside
> to the dish.  I left the coax living in the window permanently.

<Shudder>...

Coaxial cable impedance is determined by the size of the inside of the 
braid/shield, the outer diameter of the center conductor, and the dielectric 
coefficient of the insulating material between them.

A "flat" RG-6 coaxial cable is absolutely *not* a 75 ohm coaxial cable. 

It is not a suitalbe substituition for real RG-6 cable. 

It will most certainly cause a large impedance bump in the feedine, will 
introduce ghosting (which you may or may not see with a digital signal except 
as digital artifacts and instability), and will cause both jitter and 
pulse-rounding to the digital signals carried by the coaxial cable.

I can see why the ease of installation may make this attractive. Be aware of 
the effects which impedance bumps in the feedline of a satellite television 
low-noise block-downconverter may cause. If you see them, and don't like 
them, you know where the culprit is.

There is no way that such a flat jumper cable exhibits a 75-ohm characteristic 
impedance. 

This is like parking your pickup truck tire on top of your water hose and 
expecting it to work right.

<Exit RF engineer mode.)

Rick Kunath
WBCCI #3060