Antenna Adj. for Digital Conv. Boxes

[Hifirob2]

Hi All - I'm not sure where (or how) to ask this, but I have a question about the reception that my new digital converter box gets. If this has already been covered, can you link me to the thread please?

I use a roof top mounted antenna on my apartment building. It's fairly new, and works great for analog reception. But when I switched to the digital converter box, I lost three local stations - 2 (CBS), 11 (Fox), and 13 (?). I know these are broadcasting in digital because a friend of mine didn't lose these stations. Could the box be the problem?

I have heard that some antennas may need to be adjusted to get digital reception, but how? Turn it a little to the left or the right? The building maintenance guy said he'd bring the long ladder out and I could help him. Will this be a trial and error type thing, or can someone from my area tell me which direction it should be aimed for the Los Angeles basin? Right now it is 'aimed' facing SW. Or is it antenna specific? I tried rabbit ears on top of the set, but that just made it worse.

Sorry if I sound "new" to this, but I'm worried that I'll lose Family Guy and CSI Miami and I'm starting to panic!

Thanks - Rob