Good info Harvey!
And the truth of it is that it's really good to have both a 1502 and a 1503. The 1503 was intended for looking at much longer distances and it quite useful for stuff like long runs of twisted pair (telephone/etc) wiring. I use my 1503 at an equestrian center for scoping out buried wiring (700 - 800 feet long) that controls pasture watering stations. Also handy for looking at long runs of CAT5 and/or of course, coax.
The resolution of the 1502 is really nice, though, when you don't need the long distance capability.
Tom
