Yep 
Similar to a PVM. TVs had lower TVL, like 250-400 depending on size. It’s worth noting, though, that some PVMs had low a TVL, too. A 9” PVM could have 250 TVL; build quality, beam focus, connection options etc are what really distinguish a small PVM from a similar-sized TV.
I recommend taking the horizontal resolution, dividing by 3, then taking the resulting number and multiplying by 4 and setting a custom horizontal res. That way you have an exact 4:3 ratio while still using all of the vertical area of the screen. For example, if the vertical scale is 5x integer on a 1080p monitor and 1120 pixels tall: (1120/3) * 4 = 1493.333… which you round up to 1494 to perfectly center the image. The easiest thing to do here is to save the core overrides and then add a line in the config file for that core:
custom_viewport_width = "1494"
The important thing to remember is that a CRT is going to “correct” the image to 4:3, so I wouldn’t worry about pixel shape too much. Some people are really particular about such things, though, trying to get squares perfectly square or circles perfectly circular even though they wouldn’t appear that way on a CRT. If that’s your thing, more power to you.
