Do I need an antenna with a converter box?

If it's a "real" HDTV (widescreen) you don't need a converter box. Just an antenna.

If it's one of the older 4:3 models with the glass screen, you need a converter box and an antenna. Some were built with a digital tuner but, it would say so on the TV or remote (DTV) .

You need an antenna in any case. The type of antenna you need depends on your location. Start at http://www.tvfool.com/index.php?option=com_wrapper... and http://www.antennaweb.org/Address.aspx to get info about your local TV transmitters. Things like distance and construction of the building you are in are important information.

A converter box box is just attached between the antenna and TV to convert the newer digital signals to the older analog type in case your TV doesn't have a digital tuner.

All TVs made for the US market after Feb 2007 have a digital ("ATSC") tuner built into them, so if your TV is only 3 years old you don't need a converter box or external HD ATSC tuner.

Some TVs made before Feb 2007 have digital tuners, but newer tuners generally work a lot better than the early models.

Check the specs on your HDTV to be sure it has an ATSC tuner, or perhaps there is a manufacturing date on the back of the HDTV.

The tvfool results will include a "wrapper" that looks like this for a random spot in zip 90210: http://www.tvfool.com/?option=com_wrapper&Itemid=2...

So if you are in LA you need an antenna that covers both the UHF and VHF-Hi bands. But you need the results for your exact location to have a clue about how big of an antenna you need.

You need an antenna.