When converter boxes first came out on the market many manufacturers didn’t include the analog pass-through function with their converter boxes.  I recently hooked up a converter box that didn’t have analog pass-through and lost 3 channels.  I have decided that having the analog pass-through function is an absolute “must have”.  Without it you risk losing channels that you ordinarily would watch. When shopping for a converter box you should be sure that you check to make sure that the converter box you get has analog pass-through.  Many companies have already come out with upgraded versions of their original digital converter boxes but there are still plenty on the market that do not include analog pass-through.