New Calibration test<br>
This time all meters are hooked up to a single ATX power supply:
<table border=1>
<tr><th>Meter</th><th>Voltage</th></tr>
<tr><th>Fluke 77</th><td>12.49</td></tr>
<tr><th>Tektronix 502</th><td>12.49</td></tr>
<tr><th>Cen-Tech P98674</th><td>12.55</td></tr>
<tr><th>Tenma 72-4025</th><td>12.48</td></tr>
<tr><th>Cen-Tech 92020</th><td>12.46</td></tr>
<tr><th>Cen-Tech P33499</th><td>12.51</td></tr>
<tr><th>Viz WD750</th><td>12.58</td></tr>
</table>
Average is 12.51 V<br>
Standard Deviation is 39.1 mV<br>
Ugh.  Standard Deviation got worse.<br>