Full Wave Bridge Rectifier Waveform

I built a full wave bridge rectifier. I attached it to a doorbell transformer and an oscilloscope to see what the resulting waveform looks like.

I built the bridge on a breadboard, from 1N4001 diodes I bought from a vendor on Amazon. I know you’re not supposed to specify 1N4001 diodes for new circuits, but beyond the 50V rating, I doubt anything else special about 1N4001 diodes is in play.

The gray wires are AC input. The top wire is positive DC, and the bottom wire is negative DC.

I connected the probe to the positive DC wire, and the probe’s ground clip to the negative DC wire.

I measured 29.8V peak with the oscilloscope.

For reference, that’s the AC output of the doorbell transformer. The bridge’s output waveform looks exactly like the positive part of the AC waveform, and the negative part reflected across the X-axis. As it should.

I measured 60.8V peak-to-trough, or 30.4V positive peak. That’s 0.6V more than the DC peak voltage. I see that a “typical diode forward voltage drop” is 0.6V - 0.7V, so I’ll say the lower DC output peak is due to that.

I have a Commercial Electric digital multimeter. It read 22.15V_AC doorbell transformer output. It gave 9.46V_AC and 19.47V_DC at the full bridge rectifier’s DC output, I’m not sure this means anything other than that multimeter doesn’t deal with DC with a huge ripple.