Somebody over at the shmups forum made a bunch of TVL test images for CRTs. I forgot who this was (Sam?), in any case, all credit to that person. To use them, you need to output a horizontal resolution of 2560, then pick from the appropriate vertical resolution set you want to use from the pack. It ranges from 240-1600. You can then use an image viewer (such as the one from RA) to flip through the images. An explanation pic of how it’s to be used:
I’ve uploaded the images here:
https://www.mediafire.com/file/xo3hfqdw155ijk1/2560+TVL+Image+Mega+Pack.zip/file
According to it, the TVL of my CRTs:
Eizo CRT monitor: ~ 640 (probably just 600, as this matches max res).
Telefunken TV (21") :~384
AEG TV (15"):~ somewhere between 274-320
Unlikely you’ll discover something too surprising with this, but maybe interesting to some.