Magnetometer Malady

I lost the original message, unfortunately. Someone wrote to me that they had constructed my magnetometer -- published worldwide -- and it's "needle was off the dial", so to speak. Assuming that he made no constructional mistakes, there are two reasons this could happen. My magnetometer is extremely sensitive. For example, waves on the sea shore will overwhelm it, pebbles on a pathway, or a nearby lorry. Get it into the middle of nowhere, and keep it still -- then see. Another possible problem is component tolerances. In that case, cut the feedback of the digital inverters, which means reduce the resistance from one or two outputs to inputs (matching ones on each side). Component tolerances includes the size of the pickup coils. Mine were big enough to pick up events in outer space.