Before 20 years I had build the Kit of this analog tone generator ..
Back in time , I was need mainly the 1K frequency , as modulation tone , so to test FM transmitters .
Later on it become useful testing audio circuitry s .
But I was not totally happy with it, because just setting it, at one specific frequency, was a big issue,
the pot (single turn) was not that helpful ..
So I decided to improve it at the max ..
One new Burns 10K (10 turns) pot , made the deference ..
I Did also some small adjustments ...
And now my fresh improved generator , tunes smoothly at all range ..
Pictures ..