[morzh]

Adding BK counter (same as Ron did) helped but it was a half-measure. I mean, I paid $20 for a working unit so either Leader SG-11 or Heath SG-8 paired with it was an inexpensive setup, so I did not lose much by retiring it to the shelf.
Half-measure it was because the SG, in addition to the absolurte inaccuracy (scale vs the actual frequency), and the waveshape that was all but sinewave (and I was playing with the cathode follower that made it such - nothing helped), the frequency also drifted. Slowly, but by time you adjusted the trimmer or what have you it could go away by 100Hz, and if you did not re-adjust it every time netween the adjustments, at the end of it the frequency could easily drift by a few hundred HZ to 1kHz. No amount of warm-up helped.
So, yes, get thee a nice synthesizer, old or today's, make a protective cable with two back-to-back diodes, and this will make you a very happy alingnment person.