Low Voltage using Road Rage Charge Pump

[franblanc]

I have constructed a Univibe clone pedal which works. I am trying to make it work using a 9 volt DC supply and a charge pump using the LT1054CP Integrated Circuit. I was hoping to get 18 volts out of the charge pump from the unregulated 18 volt supply(Road Rage 2019) but it supplies less than 17 volts. (It varies rapidly from 16.5 volts to 16.9 volts). I have measured the voltages around the circuit and I have enclosed them in the attached circuit diagram. I have corrected one ground loop already but I cannot get the voltage to stabilise at 18 volts or near it. I believed the problem might be at D3 1N5817 Shottky Diode because that's where the voltage starts to jump around from 13.0 to 13.3 volts. However all three 1N5817 offer 179 approx on the diode setting of my multimeter so that is consistent. The Road Rage 15 volt regulated supply offers 14.9. The Univibe PCB also has a 7815 voltage regulator to deliver 15 volts, is this bad practice adn should I remove the Road Rage L78L15ACZ regulator? All the components were purchased new from Mouser. My question ..is it normal for charge pump out voltages to vary so much? Do the enclosed voltage readings mean I have a bad LT1054CP? (C5 and C6 were omitted from the design as per instructions.)