I am replacing a resistor on a PCB. The res in question is 820 ohms. That slot on the board, reads "820 1K" The 820 of course tells me the value of the res; is it possible to discern what the "1K" means?
Why do you say: "The 820 of course tells me the value of the res"? Maybe the 820 tells you reference designator and 1K is actually the value. Maybe "820 1K" is the range of acceptable resistors. I've never seen this. Maybe a picture or schematic would help.
I would guess those are alternative values, maybe for different tubes, for example instead of ECC83 it could be for E88CC which is a similar but more 'robust' type for rugged applications. That value isn't particularly critical anyway.