<VV> Re: Dwell Tach

[Padgett]

>They all read different.  I have one that I use consistantly because I 
>know it will not lead me too far astray but that is not what we use 
>instruments for.  They are supposed to give us the facts Mam.  So how does 
>one find a standard to calibrate them with.

Well I use a scope-calibrated Wavetek 114 audio signal generator for RPM 
and in square wave mode for a reference 30 degrees (6 cyl) of dwell. I use 
a crystal reference to calibrate the Tek scope. Is close enough for 
government work. Is how I determined that my old meter was no longer 
holding a reference (suspect a popped zener since RPM varied with voltage 
supplied, may fix one of these days).

Signal generator is also good for calibrating a tach at 7000 rpm and 
holding  there for a while. All things I used to do before getting into 
computer cars.

Padgett