dwell and points

i have a sun tester but it does not work is there another way to check dwell say with a fluke voltmeter if so how could i do it my engine seems to runnin pretty rough at idle 273, non stock 4 brrl , i hear one of my valve clatterin not bad though could that be a cause ? i hooked up the vacum advance straight to manifold could hear a change revedd up so vacum is workin checked points at .017 could my points be bad and still run thanks for any info