Printer Friendly Forum Posts - How To Boost AC Voltage From Magnetic Coil Pickup?

I've done a diesel engine swap in my previous gas vehicle. The last thing I'm trying to figure out is how to drive the tachometer. I have a converter box from Dakota Digital which can take the signal from the diesel engine and convert it/calibrate it to proper signal for the gas tach.

The diesel gets its tach signal from a magnetic coil (induction) pickup on the injection pump timing gear. The problem I have is that at or near idle speed the pickup is putting out 0.7Vac, and the converter box needs at least 1V to read the signal. I know the converter works because if I rev the engine till the output is > 1V it will read it.

I emailed Dakota digital tech support and the answer was " You could try Teeing in a 1K resistor to 12 volts to pull the signal up. Our module needs at least 1 volt AC. " Which I just tried, however it had the effect of dropping the voltage from 0.7 to 0.2v instead of pulling it up.

So my question is, Is there any simple way to use DC power to boost the AC output of an inductive pickup? Perhaps I didn't "tee in" the resistor correctly? I'm good at mechanics, but not so much at electrical theory, any help is appreciated.