# Digital Analog converter box also improves analog picture



## dorfd1 (Jul 16, 2008)

I have a directv sd receiver and an atsc digital to analog converter box I also have an rf modulator that outputs on channel 6 the rf modulator signal is combined with the d11-500 rf signal. the digital converter box is set to pass through. the strange thing is I get snow on channel 3 when the digital converter is off but when I turn the converter box on the snow is removed.

can anyone explain this.


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## harsh (Jun 15, 2003)

How did you "combine" the signals?


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## dorfd1 (Jul 16, 2008)

harsh said:


> How did you "combine" the signals?


using a splitter in reverse


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## Stuart Sweet (Jun 19, 2006)

Using a splitter in reverse isn't really the best way to combine signals. There are devices that will do that. I'd say that maybe you got lucky as a result of the DTV transition, that perhaps there is less interference than there used to be.


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## dorfd1 (Jul 16, 2008)

Stuart Sweet said:


> Using a splitter in reverse isn't really the best way to combine signals. There are devices that will do that. I'd say that maybe you got lucky as a result of the DTV transition, that perhaps there is less interference than there used to be.


channel 3 has the directv box signal and channel 6 is th rf modulator.

when the box is off channel 3 has snow when I turn the box on the snow on channel disappears and the picture is clear. there is no difference with channel 6


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## Stewart Vernon (Jan 7, 2005)

I'm trying to imagine your configuration. It sounds like:

1. DirecTV RF output
2. Digital-to-analog RF output
3. RF modulator

It sounds like you have 3 "outputs" for only 2 sources. What are you using the RF modulator for?

Maybe we need more info.

Outside of that bit of confusion...

Not all "pass through" scenarios are created equal. I've seen a few pass-through scenarios (VCRs as an example) where they did not pass-through as cleanly when they were off as they did when they were on.


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## dorfd1 (Jul 16, 2008)

Stewart Vernon said:


> I'm trying to imagine your configuration. It sounds like:
> 
> 1. DirecTV RF output
> 2. Digital-to-analog RF output
> ...


an antenna is also connected to rf modulator.

1 and 3 and combined then fed into the converter box the rf out of converter box is fed into a vcr which is fed into a tv.

I use the rf modulator for the s-video output of my computer


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## Stewart Vernon (Jan 7, 2005)

Ok.. I'm inclined to go with my gut reaction, then...

Some "pass-through" devices actually only pass-through when they are on for some reason... others still pass-through, but not as well. It's entirely possible that is what is going on in your situation.


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## harsh (Jun 15, 2003)

I'm baffled. What do you see that's snowy? Is it the DIRECTV receiver or a fuzzy version of something else?

The setup that I think you have may involve passing a signal through two pass-through devices (are you CERTAIN that the converter passes through???) as Stewart suggests.

Does your TV have only a single RF input?

Do you have poster with a matrix for what needs to be turned on and what needs to be turned off to see what you want so that others in the home can use it?

If it were mine, I'd bag RF and try to connect everything line level; even if you must use a switch. There are a couple of switches that will accept up to four line level inputs (either S-video or composite with stereo audio) and produce a single output to composite, S-video, or channel 3. The Philips PH-61153 is cool because it includes an RF modulator. You probably need something capable of manual switching though.


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## dorfd1 (Jul 16, 2008)

harsh said:


> I'm baffled. What do you see that's snowy? Is it the DIRECTV receiver or a fuzzy version of something else?
> 
> The setup that I think you have may involve passing a signal through two pass-through devices (are you CERTAIN that the converter passes through???) as Stewart suggests.
> 
> ...


when the conerter box is off I see a fuzzy version of the directv receiver. when the converter box is on the directv receiver is not fuzzy


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## harsh (Jun 15, 2003)

dorfd1 said:


> when the conerter box is off I see a fuzzy version of the directv receiver. when the converter box is on the directv receiver is not fuzzy


Sounds like you need to leave the converter box on (and apparently in bypass mode) and it will work the way you designed it. Is there some other problem?


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## dorfd1 (Jul 16, 2008)

harsh said:


> Sounds like you need to leave the converter box on (and apparently in bypass mode) and it will work the way you designed it. Is there some other problem?


no other problem.


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## harsh (Jun 15, 2003)

dorfd1 said:


> no other problem.


So what was the point of this exercise?


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## dorfd1 (Jul 16, 2008)

harsh said:


> So what was the point of this exercise?


to ask why the converter box improves analog picture


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## Stewart Vernon (Jan 7, 2005)

dorfd1 said:


> to ask why the converter box improves analog picture


But it probably isn't. The truth is probably that the converter box is hurting the signal when off, and passing-through when on... not that it is improving it.


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## harsh (Jun 15, 2003)

How does one access the twit list feature?


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## RobertE (Jun 10, 2006)

Stewart Vernon said:


> But it probably isn't. The truth is probably that the converter box is hurting the signal when off, and passing-through when on... not that it is improving it.


One very remote possiblity is that the DirecTv box is pumping out to hot of a RF signal overdriving the TV tuner. Adding all the stuff inbetween knocks it down enough where the TV tuner is happy. Other than that, I got nothing.


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