R102 has been changed to 150K to limit the frequency range of the COARSE control over the range 5Hz to 50kHz
By changing R130 to 300K you can sweep the input from -15V to +15V for a 0 to 100% range in pulse-width modulation.
R115 has been set to 1M5 to allow the `resting frequency' of the VCO to be set to the low end of the frequency spectrum (approximately 909Hz)