‰  NOW 13 WPM  ‰  TEXT IS FROM APRIL 2018 QST PAGE 53  ‰

WHILE ADDING OR SUBTRACTING A LOAD IS OF INTEREST.  I SET BOTH THE NEGATIVE
AND POSITIVE SUPPLIES TO 4 V AND THEN CONNECTED AND DISCONNECTED A 4
RESISTOR A 1 A LOAD.  THE OUTPUT CHANGED APPROXIMATELY 100 MV ON EACH
SUPPLY.  I SAW SIMILAR RESULTS WITH THE 5 V SUPPLY.  ANOTHER TEST OF
INTEREST IS THE EFFECT OF SETTING A VOLTAGE AND CONNECTING A CIRCUIT, THEN
SHUTTING OFF THE POWER AND TURNING IT BACK ON AFTER A FEW MINUTES.  SEVERAL
TRIES SHOWED A SMALL CHANGE IN VOLTAGE IN THE SECOND DECIMAL PLACE, ON THE
ƒ  QST DE W1AW  ‰
ORDER OF 10 OR 20 MV.  I RAN THESE TESTS WITH A 4 RESISTOR A 1 A LOAD AT 4
V ON THE VARIABLE SUPPLIES, AND A 1R25 A LOAD ON THE 5 V SUPPLY.  I RAN THE
SAME TESTS ON THE VARIABLE SUPPLIES WITH A 12 LOAD AT 12 V WITH SIMILAR
RESULTS.  NEXT, I CHECKED STABILITY OVER TIME.  WITH THE 12 LOAD AND THE
POSITIVE VARIABLE SUPPLY SET TO 12 V, I SHUT OFF THE VOLTMETER AND LET THE
POWER SUPPLY COOK FOR 3 HOURS.  WHEN I RECONNECTED THE VOLTMETER, THE
‰  END OF 13 WPM TEXT  ‰  QST DE W1AW  ƒ