Let me explain. In order to watch TV you need a tuner. It doesn't matter if the tuner is in your TV or provided by your TV service provider. The bottom line is having a tuner.
Where this TV or monitor question becomes an issue is when using an antenna. Since the monitor doesn't have a tuner it would need help in order to work with an antenna. The help would come in the form of an external digital tuner or a digital-to-analog converter (also called a DTV converter box).
If you own a digital monitor and want to use an antenna then it makes sense to want to buy an external digital tuner so you can watch HD for free. The thing is that external digital tuners cost a lot more than a DTV converter box, so my recommendation is to buy a DTV converter box and live with the standard digital resolution, which is still pretty good to look at.
Digital Tuners Required in New HDTVs
This question is somewhat dated because before 2007 there were TVs that had an analog tuner but no digital tuner. Technically, this made the product a TV - not a monitor. Back then, I had a dislike for monitors as I felt that consumers were being misled into buying monitors when they should have been buying TVs.
Over time I've softened my tone, but much of this personal improvement is a result of a Federal Communications Commission (FCC) requirement that all manufacturers must build digital TVs with a digital tuner.
The dates manufacturers had to comply with this requirement were staggered by screen size, which are noted in the list below:
- July 1, 2005: All TVs with screen sizes over 36" must include built-in ATSC tuner
- July 1, 2006: All of 25-35" TVs must include ATSC DTV tuner (right now only 50 required)
- July 1, 2007: All of 13-24" TVs must include ATSC DTV tuner
- July 1, 2007: All interface devices must have ATSC DTV tuner (VCR, DVD player/recorder, DVR, etc)
Keep in mind though that this FCC requirement only applies to new units. Products made before the deadline are exempt from compliance. However, manufacturers are required to put a sticker on TVs that aren't ready for digital TV.