27" magnavox B&W focus problem

[DaveWM]

focus adj has some effect, but not much, checked the voltages on the two grids pin 3 580 and 4 at best focus 580 with the focus pot turned all the way from ground. the sams says 545 and 365.

I was wondering if something else would cause an out of focus condition?

other than that the picture is pretty good.