it's a sputnik, but how old is it? did you buy it new? who assembled it?

from the sounds of it your topcap is tightened a lot. this is probably a bad thing. whenever you 'adjust' the headset you should unscrew the top cap until the headset can reseat itself before tightening it more. it's very important to loosen the topcap bolt before tightening it.

i'm going to guess that you or someone before you either
-ovalized the headtube and the headset can no longer sit straight
-overtightened the topcap bolt and damaged the headset bearings and/or races
-are tightening the stem before the topcap so any tightening you do to the topcap bolt is simply pulling the starnut out of the steerer tube instead of preloading the headset.

i'm actually convincing myself as i write these out that it's the last one. did you undo the bolts on the stem's steering tube clamp mechanism before adjusting the top cap bolt?

basically, if you're adjusting the headset properly and it's still making a noise, something is broken or bent or pitted.