Digital-to-Analog Converter Questions

[jfine]

These questions are from having to buy the Digital-to-Analog Converter box when they stop broadcasting analog. I currently have a large roof antenna that pulls HD channels in nicely on a new set that has HD/digital tuner built in.

This is for the tv's in my house that are older that need the Digital-to-Analog Converter box.

1) Do most or all of these Digital-to-Analog Converter boxes pull or receive/decode HD channels (or however you put that)? As I dont fully understand HD, it seems like just another digital broadcast that must be converted to analog, so it would seem all the boxes should do it. If I am getting HD now on my new TV, the boxes should pull them too using the same antenna, right?

2) When turned off, these boxes should just pass the signal for current analog stations. Do they or is there a bypass somehow?

3) Do these boxes differ in how strong the tuner pulls in the signal? In other words, how can I find a brand name box specs that will help me decide how well the signal will be pulled or decoded? I know some of my TV's seem to have a better picture under the same circumstances that have to do with tuner or signal strength. Or all these boxes just a converter and nothing else?

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