View single post by Mark Rosenbaum
 Posted: 01-06-2006 03:47 am
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Mark Rosenbaum

Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
Attached is a rather poor photo of the interior of a JH tach.  Either I'm an even worse photographer than usual, or my camera isn't working all that well tonight -- this was the best of eight tries.  You're right, only one transistor, so obviously it has to be a different circuit than the one I provided.  I've spent more than forty years in electronics, yet I missed that small but vital detail in several previous examinations... aargh!

Several owners have reported what sounded like MG tachs in their JHs, that worked just fine.  Since both cars have 4-cylinder engines no recalibration should be necessary.  But then you don't know what a PO might have done to the MG tach, so it wouldn't hurt to check its calibration, if you can.

Attachment: tach interior.JPG (Downloaded 148 times)