I have a Van's Series Tach with the 12" extention sender unit (part number IE VTACHGEN 12) that has been working fine for 500 hours. I landed the other day and noticed on roll out my tach was reading only 200 rpm. It had check just fine on run-up just 10 minutes prior. After doing some run ups and flying to check it out, it reads exactly 400 rpm low across the entire rmp range. I know that since I have a back-up optical tach feeding my flight data recorder and they have always read within 50 rpm of each other in the past.
I replaced the sender unit last weekend, based on reading a few threads here on VAF, but still have the same issue. I checked all the leads to the tach and they all look good. Before I buy another tach I thought I would see if anyone else has had this issue with the Van's Tach.
I replaced the sender unit last weekend, based on reading a few threads here on VAF, but still have the same issue. I checked all the leads to the tach and they all look good. Before I buy another tach I thought I would see if anyone else has had this issue with the Van's Tach.
