Hello and welcome!
Yes, you TV will work without an external converter box. Your TV has a built-in tuner capable of receiving digital TV (ATSC) broadcasts.
BTW, indoor antennas are always more susceptible to random signal issues than outdoor antennas. This includes things like unknown building materials, signal reflections, people walking by, electrical interference, antenna obstruction, etc. Although it is possible for indoor antennas to work in some situations, I still urge most users to consider an outdoor antenna for a better overall viewing experience.
Your strongest channels are coming from a lot of different directions. For this, I would suggest two possibilities:
1) Try an omni antenna like the Channel Master 3000A or Winegard MS-2000 on your roof.
Advantages: Omni design allows the antenna to pick up signals from multiple directions without having to adjust the antenna each time. NOTE: Antennas are never perfectly omni-directional, so even though it claims to be an omni antenna, you should still experiment a bit with aiming the antenna in different directions during initial installation for optimum reception.
Disadvantages: Omni antennas are susceptible to multipath (a.k.a., "ghosting", multiple signal "echoes" entering the antenna from all directions). This might make it more difficult for your tuner to lock on to some channels. Omni antennas also have relatively low gain intrinsic gain (not counting the gain of the built-in amplifier), so don't expect it to pull in the weaker, more distant stations.
2) Use a high gain antenna like the Winegard HD7696P and an antenna rotator like the Channel Master 9521A.
Advantages: High gain antennas are much better at dealing with multipath, so if your environment is susceptible to lots of multipath (usually places with lots of tall buildings, trees, and/or hills for the signals to bounce off of), these antennas can help clean up the signal. The high intrinsic gain of the antenna also makes it possible to pick up weaker, more distant stations, if you aim the antenna properly.
Disadvantages: You cannot pick up stations from a wide spread of directions at the same time. You need to turn the antenna each time you want to watch a different group of transmitters (e.g., Portland vs. Concord/Manchester stations).
Since you mentioned that you are only interested in the "green" stations on your list, I would start with an omni antenna first. However, if multipath turns out to be a big problem, you may need to switch to a more directional antenna later.
BTW, if you go with one of the larger directional antennas (i.e., HD7698P) and add a pre-amp (like the Channel Master 7777, Winegard AP-8700, or Antennacraft 10G202), you may even be able to pick up some of the stations from Boston.
One more note... Your report indicates that it was only resolved to "street level" accuracy. Perhaps the address lookup engine was not able to resolve your exact location. Just to make sure you have an accurate signal analysis, it would be best if you could re-run the analysis for your exact location. You can do this with the Interactive Maps tool (
here). After entering your address, you can change the location of the signal analysis by dragging/dropping the orange marker until it is right on top of your house (switch the map to "satellite" or "hybrid" view for the best detail). When you are satisfied with the location and antenna height settings, you can click on the "Make Radar Plot" button to generate a new signal analysis report.