Has anyone built Jim's monitor from Kitplanes Nov issue? I have breadboarded it and it works when the batt voltage goes to 12VDC but when 14V is applied it has a slow repetitive beep. The V at pin 9 on stage C of the Op Amp shows the C slowly discharging and when it hits zero it pulses to 4V and beeps. If I can fix this I will order some boards and build a few.