LM13600 VCO experiment & question

[Scott Gravenhorst, Synthaholic]

Just breadboarded the LM13600 VCO from page 2-527 (fig 15) of the 
manual.  The description claims that the circuit "provides signals from 
200 kHz to below 2 hz as Ic is varied from 1 mA to 10 nA."

The formula for Fosc is Ic / ( 4 * C * Ia * Ra )

Since the denominator calculation is a constant, this should provide a 
100,000 to 1 change in frequency as described above.

The circuit oscillates, but when I apply 15v to the CV input as opposed 
to grounding it, I see only one octave change in frequency.  I also 
tried applying a CV by means of a potentiometer wired as a voltage 
divider.  Same result, max to min, only one octave.

has anybody else played with this circuit?  It's really simple and 
provides square and triangle outputs.  If I could get it to work like 
the book says, it might be useful, but at one octave range, not much.  
Is it possible that the book is wrong?  
-- 
-- Scott G., Synthaholic

There is no 12 step program for synthaholics.  Thank your Superior Being.