[ccomer1955]

OK. Hopefully I can figure things out from here, but I wanted to ask one more question if I may. I have my new shielded test leads in place. I got two: one with a 100Hz probe and another with two alligator clips. With the probe attachment or the alligator clips plugged in and not actually testing anything (just lying on the bench), I get this sine curve on my screen with the scope set as shown (all the lowest settings of sweep range of 10-100 and v. att of 1 and AC). Is this what I should be seeing, or shouldn't the curve be a smooth curve? My camera only caught one part of the curve, but my eyes see it repeating on the screen. Do I have some adjusting to do, or am I seeing the electrical interference that my house is prone to (ALL of my tube radios have Rf noise from about 1000-1700 on the dials.