asm1-VCO DRIFT!!

[e]

Hi all
i have  implanted my own build
regulator i (7815/7915) and i have notice this new disturbinese in the force 

every pot. that has + to - 15 range
such as the FC (filter section) pot , or pwm pot. causes the vco to drift
slightly while tweaking.
when the turn reaches the limit suddenly a small shift in the osc, is heared.
i scoped it , the change is measured like 30 to 40 mv shift.
(checking the coarse tune middle leg)

another fact is when i use my huge lab regulator , this anomaly 
almost dissapear , at least from the hearing range.

tnx 

Aln