Calibration problem Spectra V3

[ton69]

After repairing the spectra V3, it turned out that it is not calibrated (inaccurate vdi, does not balance the ground). I tried with different ferrites at different distances from the coil, but it does not calibrate correctly. There is a magic that I do not know.. If anyone has experience and decide to share, I will be gratefu

[Carl-NC]

Are you running the calibration routine? The password for that is "Zap". Then it does an air cal (make sure the coil is far away from any metal); then the ferrite cal (mostly you want to make sure you don't overload it); then the salt cal (use a gallon of salt water, homemade is fine). It's pretty straightforward.

[ton69]

Thanks Carl. I think I'm doing it right. Air calibration-ferrite-salt. Ferrite from magnetic antenna 10/10mm at a distance of 8-10cm. Calibrates vdi -68(-70) not -95 as it should be. For salt calibration I tried cdr. Very long time for air calibration??. I'll try again today. The coil is not WhiteS. Detech28/30cm.

[Carl-NC]

We always did calibration with a 950 concentric. As I recall, DD coils did not work well for this.