[Fot] electric tach to fit TR4 tach body?

[J.C. Hassall]

On 12/4/2009 4:37 PM, Chris Kantarjiev wrote:
>> Chris, I'm not sure I understand this statement.
>
> My experience with the electric tach conversion in my TR4A is that the
> tach is not very happy. I wasn't able to do careful measurements but the
> little that I did led me to believe that the voltage was likely to drop
> *below* the critical voltage of whatever regulator is now inside the
> tach shell!
>
> In another car, I've had problems with voltage swings and electronics -
> a rally computer, something *made for automotive use* would reset itself
> mid-event, apparently because of voltage issues. The manufacturers
> realized that this was a problem and sell another box to do "voltage
> conditioning" :-)
>
> Dunno. All in all, a mechanical tach might be a better way to go in our
> old cars!

I'm sadly coming to the same conclusion.  I thought about designing a 
voltage conditioner, but decided I've created enough "side projects" 
with this car :-/  To compound the voltage problem, many of the tachs 
I've looked at won't work with my Crane ignition, and there's no chance 
I'll give it up.

jim

-- 
Jim Hassall
Blacksburg VA
'63 TR4 in autox preparation
99% finished, 90% to go