If one mag goes off line, the P1000 turns on the appropriate LED. It
actually counts the number of times the mag fires and displays the warning
if signal to one is lost. When you switch to Right or Left, the
corresponding LED lights and the display shows the RPM drop.

There is also a yellow LED which lights if there is more than an 80 RPM
difference detected between the two mags. Obviously they are both turning
the same speed but, if one is firing intermittently, this will tell you that
the roughness is due to a mag malfunction and not something else in the
engine.

We have the P1000 in our 172 N and I really like it. It also has an RPM
trap feature so you can determine what the fastest engine speed during your
last flight was and the ability to turn off reading of either mag to help
diagnose mag malfunction.

The only problem we had with it was at the beginning when members would push
a button, put it in the diagnostic mode, and think there was a mag problem.
A couple flights were canceled but we haven't had a problem after the first
couple of weeks.

I highly recommend this unit. It is so accurate that you will notice any
RPM drop due to carb ice immediately. It is so accurate that it gives you a
faster indication of pitch up or pitch down (with a fixed pitch prop) than
the VSI. We also haven't had anyone leave the master switch on since we put
it in because the LED's and display make it very obvious that power is still
on.

You can read the manual he

http://www.baldeagleflyingclub.org/members/Tach.pdf

--

Roger Long



"Kyler Laird" wrote in message
...
Bob Noel writes:

Also, the P1000 will annunciate
a bad mag, which the R-1 does not.

I highly recommend having this feature and its relative, "mag drop".
It would be a shame to switch to an electronic tach without getting
such basic features as a result.

In fairness to the R-1, it does have the "mag drop" feature.

O.k., I'm stumped. How can it tell you that it's measuring mag drop
without telling you that one of the mags isn't firing?

--kyler