Re: Digital converter (for t.v.) problems - help appreciated

Posted by Svetaswan-2 on
URL: https://www.es-forum.com/Digital-converter-for-t-v-problems-help-appreciated-tp1553564p1553588.html



Sobering stuff about the t.v. "amplifying" RF noise. Correct me if I'm wrong, but I would assume that an LCD TV would do this more than a CRT TV - due to the fact that they use their own switching power supplies (I think?), use CCFL backlighting, generate more RF than CRTs, etc. And I think I may need to buy a LCD TV in the very near future - which makes getting this problem under control even more crucial.

I'm not tech savvy at all (in case this wasn't already apparent ;) ) - and have no experience with tinkering with electrical components, replacing parts, customizing, and stuff to that end. So how does a totally inexperienced person like myself go about switching the power supply of the Comcast "Digital Transporter Adapter" (its "official" name) from "switching" to linear? (Without harming the device, of course.)

~Svetaswan

--- In [hidden email], "cris_aov" <cris_aov@...> wrote:

>
>
>
> I think the power supply may be the main problem, the power supplies usedfor 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 tothe 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 morethan 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 andthe 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
>