Will I need a digital antenna after conversion?

If you intend to watch free Over The Air TV, you will need an antenna. Any TV antenna will work equally well for analog as for digital. There is no such thing as a "digitl" or "HD" antenna, that's just marketing hype. You do need a VHF/UHF antenna though, as many communities have stations in both bands.

If your current antenna is not rusted or bent and you are getting all the digital channels, you are all set. If you are missing channels, you may need to upgrade your antenna. Visit http://www.antennaweb.org/ . Based on you zip code, the site will give you a list of stations in the area, suggestion on the proper type of antennas and guidance on where to aim them.

i will point out I also have a constrained expertise of how the hot digital boxes are working, yet I do have faith they are broadcasting on the UHF band. as quickly as the swap happens stations would be outputting a highter capacity lever on the UHF area as they gained't could dedicate the capacity to the VHF area. As for VHF antennas they'll substitute into ineffective after the swap, thats the factor. (VHF demands extensive bandwidth and capacity which cable companys and the FCC choose to unlock for different makes use of) desire this enables.

all you need is a UHF antenna. The digital tv channels are broadcast the same ways as they always were... vestigial single side band

You are good to go as you have it.