No, I believe the rs170 connector is putting out an analog NTSC signal. The digital 640x480 picture is being converted to an analog NTSC video of scan lines which do not correspond exactly to the 480 rows of pixels. Therefore some rows are being ignored.
Someone may have a better explanation of the process, but to my knowledge a different dvr won't matter.
That is why to capture the high quality image the IRD scopes put out people have been recording with a device looking through the ocular.