1. If you set it to use "native" the resolution will change to match that of the content. Otherwise it will remain where you set it, up- or down-converting the content to match the setting. Whether you want the receiver or your HDTV to do the conversion is up to you (using native does slow things down a bit, however).
2. If you are using the audio system of the HDTV, using HDMI will result in digital audio. I don't do this but have the optical digital output going to my Pioneer audio receiver. With this there is a big difference in level between DD 5.1 and non-DD channels (DD is much lower).
3. The active button gives access to some special features. There are no HD10 or HD20 models. There was an H10, but it was replaced by the H20 about a year ago. The H20 does not yet have "active" enabled, but the HR20 DVR does. The features include being able to switch audio on the mix channels, access to weather information plus some other features.
4. That depends a lot on what sort of antenna you need. Radio Shack has some for as low as $25 and you can go up to several hundred dollars. You will also need cable to connect it to the receiver. Both indoor and outdoor antennas are available. There is some good information on choosing an appropriate antenna at http://www.antennaweb.org. In addition to those channels, you would be able to get the HD versions of channels not available in HD from Directv, such as PBS.
2. If you are using the audio system of the HDTV, using HDMI will result in digital audio. I don't do this but have the optical digital output going to my Pioneer audio receiver. With this there is a big difference in level between DD 5.1 and non-DD channels (DD is much lower).
3. The active button gives access to some special features. There are no HD10 or HD20 models. There was an H10, but it was replaced by the H20 about a year ago. The H20 does not yet have "active" enabled, but the HR20 DVR does. The features include being able to switch audio on the mix channels, access to weather information plus some other features.
4. That depends a lot on what sort of antenna you need. Radio Shack has some for as low as $25 and you can go up to several hundred dollars. You will also need cable to connect it to the receiver. Both indoor and outdoor antennas are available. There is some good information on choosing an appropriate antenna at http://www.antennaweb.org. In addition to those channels, you would be able to get the HD versions of channels not available in HD from Directv, such as PBS.
