[DeTomaso] Modifying The Pantera Tach For 6A Tach Signal Direct Input

[SOBill at aol.com]

Thomas,
 
The Pantera tachometer could be modified to use the TACH signal  directly 
from 6A ignition box.
This would eliminate the requirements for the less than totally  reliable 
tach adapters. The modification would require pulling the tach  from the car 
and changing the input circuit filter consisting of R9, C1,  R8, and C2 on 
the tachometer circuit board. I have not determined, done, or  tested the 
required modifications.
 
I have posted the tachometer schematic at 
_http://www.poca.com/gallery2/main.php?g2_itemId=18578_ 
(http://www.poca.com/gallery2/main.php?g2_itemId=18578) .  This schematic can be printed directly by right clicking and Print 
Picture. This  print will be about 1/2 of a page in size. A full page schematic 
can be had by  right clicking and Save Picture As and then printing the 
picture as stored on  your computer.
 
If you make and test the required modifications, let me know what  works 
and I will post an updated schematic.
 
Have fun,
 
SOBill  Taylor
sobill at aol.com  

 
In a message dated 4/16/2010 11:51:46 P.M. Pacific Daylight Time,  
Thomas.Tornblom at hax.se writes:

SOBill at aol.com skrev:
> EA,
>  
>   
> Installation 
> The White wire of the  8920 must be  connected to the Tach Signal 
connection 
> on the 6A.  The Tach  Signal connection on the 6A will have a 20% duty 
cycle 
> 12v   square wave on it. One pulse for each spark  occurrence.   

This sounds like the tacho could be made to work by just bypassing the  
series resistor on the tacho signal.

Didn't you have a schematic  for the  tacho?

Cheers,
Thomas