Tachometer needle bouncing

I've had a problem with my factory rally tach needle bouncing. Sometimes it will almost peg the gauge during acceleration. At idle it will bounce from 700 rpm up to 1500 and beyond.
I did a complete n & b restoration on the car, finishing it up last fall.
It is a 1968 Charger R/T, 440, 4 speed. Everything is pretty much stock with the exception of the electronic circuit board for the tach and the solid state voltage limiter for the dash gauge circuit.
The other gauges work as they should. The gray tach wire is connected to the negative terminal of the stock coil. I rebuilt the dual point distributor and it is all stock as well. The spark plug wires are the reproduction date coded wires sold by Classic Industries.
I'm looking for thoughts/ ideas on which way to go.
Has anyone experienced this problem?
Thanks, Bob

Never had this trouble but, I'd look right at that tach.
Mike

It's a semi-known issue with stock tachs. I would ask these guys in an e-mail....

https://www.rt-eng.com/index.php/RTE_67-74_Tach_kit.html

Suspect points bouncing. Check gap and was the cam lubed?

When my (aftermarket) tach was bouncing around, it turned out to be a bad connection in the ammeter. Progressively got worse until I figured it out and bypassed it. Steady as a rock ever since.

I experienced a similar confition. I have the RTE tach board in the tach, stock coil and an origional Prestolite dual point distributor with NOS Mopar points and condenser. The tach needle would fluctuate and bouncing around and at low RPM's sometimes the engine would stall, but would immediately restart. Changed the coil no difference, changed cap and rotor no difference, changed the coil wire no change. The fix was a bad or going bad condenser. Installed new points and condenser....end of problem. Points set @ 0.016" both sets...btw use ventilated points.
BOB RENTON