Problems with Tacho & RPM Feed

[nikpro]

I have taken a feed from my tacho signal wire to the RPM input on the AX22 which now logs RPM perfectly. The only problem I have is when this wire is connected to the RPM input on the AX22 it stops the tacho working, as soon as I disconnect it the tacho works fine?

[jlucas]

There's an impedence mis-match, that's why the tach is going dead. Contact your local RT office directly for an isolator circuit.