How to add Astro Feed into MythTV via Composite (Video/Audio Input)

I was unable to get clear reception if Free Air Station (TV3) ..
After tried with few type of antenna and booster ,eventually I had to opt to Astro.

Luckily got previous installed Astro Dish installed at my new home..
so I just borrowed a decoder from my mates for this few days..

First I make sure these few things got connected :

1. From Satellite Dish to Astro Decoder box.
2. From Astro Decoder Box to TV Cards (PVR150) Video/Audio Input .

.. then

using root.

“service mythtvbackend stop”

then run
“mythtv-setup”

Get to the first screen and the rest of setting as below :
( Change the default from “Tuner 1” to “Composite 1”)
Somehow changing this on-the-fly while switching channel on same card.. doesn’t work

Then need to assign the input the video source.

then need to append channel if new* ..
else it will just work.. if you’re replacing the existing video source ( with same name )

so ..after that can have better reception such as this ..

p/s : .. going to add a set-top box to my wish list.. !