T

terrykohler

Well Known Member
I have been using a Van's ammeter wired thru a shunt since day one. When I turn on my strobes, the ammeter is typically jumping from zero to about three amps with each pulse. Also, when I key my mike (thru either PTT switch), I'm getting deflection of over 5 amps in some cases. Funny thing is that the deflection can be in either the +/- direction. I've checked for grounding errors and can't find any. One other builder told me early on that he gets the same thing and it's likely an instrument error. I'm getting tied of looking at this "problem" without fixing it.
Any suggestions out there? Is it necessary to use shielded leads from the shunt to the gage? This spiking does not occur when I turn on other electrical devices and only occurs when the alternator is on line.
 
Nervous Ammeter

Hi Terry,
as the other link points out, you might be picking up RFI from the com. The strobes do have a surge when they recharge the capacitors between flashes. You could probably clean some of this up with some small bypass capacitors to shunt the RF off the cables. Same idea as on the old cars when generators would give you whine in the radio.

Paul "Cz"
N694BP reserved
 
Brian & Paul:
I'll try twisting and moving some wires and see if that helps. Will let you know if that solves the problem. Thanks for your input.
Terry
 
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