Flightdek-D180 RPM reads low

[03733]

Can anyone give me a heads up on why the rpm readout seems to be reading at about half or real values.
I had the Dynon professionally installed so am not totally familiar with procedures for troubleshooting.
The engine is a Lycoming 320 150 HP on a Osprey aircraft

Many thanks for any suggestions

 

[dynonsupport]

Your pulses per revolution is probably set twice as high as it should be.

It's in the Setup->Sensors->Tach menu

 

[03733]

Your pulses per revolution is probably set twice as high as it should be.

It's in the Setup->Sensors->Tach menu

Thanks much

I tried 1.0
It was at 2
Some improvement but now reading a bit high it seems
When I do a mag check and the left mag is selected the rpm spikes anywhere from 500-1500 on the gaugeand fluctuates wildly. Engine performance is normal
Are 2 pickups on the mags necessary for the Dynon which is what I see has been installed.

Any suggestions?
Many thanks
Norm

 

[dynonsupport]

If you're seeing "spikes" as the RPM increases, then you'll want to experiment with the resistance on the connection to the mag p-leads. You should have 30K on there already per the installation manual, but you can step up to 100K or so. If you lose RPM at low revs, that's an indication that you've gone too far.

The dual channels lets you monitor RPM if one mag or ignition source should fail. It also lets you do a proper run-up check while still monitoring tach.