Posted by PUK on
URL: https://www.es-forum.com/Digital-converter-for-t-v-problems-help-appreciated-tp1553564p1553575.html

maybe this is what is happening with the Plasma TV set up over the road -
Sadly the attitude of the couple is its our telly its our life we will not
be told what to do by anyone, go crawl into a corner and die sort of thing.


In a message dated 18/04/2010 09:01:31 GMT Daylight Time,
[hidden email] writes:

I think the power supply may be the main problem, the power supplies used
for almost all of our electronics are called "switching power supplies" and
these generate a lot of RF noise by the very nature of how they work.

Ive found that when you electrically connect two devices (like your tv to
the DA converter box) in which each device has its own power supply, this
can sometimes create some really nasty results, I think this is what happens

1. power supply for dac box generates a lot of rf noise

2. rf noise from power supply travels to DA box and adds to the rf being
generated by the da box itself (the bulk of the total rf noise will be more
than likely from the power supply)

3. all this RF then travels to the TV and the TV "amplifies" all this
nasty rf noise as well as the rf already generated by the TVs power supply and
the TV itself.

Theres two things you have to do which I can think of that will make a big
difference, the one that will make the major difference is number 1

1. Replace the "switching power supply" of the DA box with a "linear power
supply", a "linear power supply" works differently than a "switching power
supply" , a linear power supply generates no rf or only extremely little.
Another alternative would be to replace it with a high capacity battery but
this might not be most convenient solution.

2. Have each device plugged into its own rf isolated surge protector,
something like a tripp lite isobar or the one Marc uses.

-Cris



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