WB0SMX

  Heathkit IG-42 Signal Generator Restoration – Part 2 Filed in Heathkit IG-42 on Apr.02, 2018 Electrolytic Can Capacitor Re-stuffing Next on the repair plan is to pull the 3-section electrolytic can capacitor, and re-stuff it with modern electrolytic capacitors.  This will ensure reliable operation for decades into the future, while preserving the looks of the old equipment.  I unsoldered the two resistors, the .05 uf capacitor and the various wires from the terminals of the can, being careful to note what each terminal had for connections.  Once that was done, I was able to unscrew the two screws holding the can to the chassis, and remove the can.     Electrolytic Can Capacitor removed from chassis The can bracket lifted off, after un-twisting the four tabs on the can. I worked for about a half hour, attempting to uncrimp the edge of the aluminum can from the bottom.  I tried a pocket knife and a small screwdriver, but I got nowhere in that endeavor.  Finally, I changed

  Heathkit IG-42 Signal Generator Restoration – Part 1 Filed in Heathkit IG-42 on Apr.02, 2018 The first fix applied to the IG-42 Signal Generator was the replacement of the 0B2 regulator tube. With the new old stock replacement, the B+ voltage dropped from 131 vdc to about 107vdc. The 0B2 is a 108 volt regulator, so that should be about right. The new tube voltage chart is displayed below. I have not replaced any resistors or capacitors at this stage, so these readings may change again in the future, but they are much closer to specifications, now. TUBE Pin1 Spec Pin1 Actual Pin2 Spec Pin2 Actual Pin3 Spec Pin3 Actual Pin4 Spec Pin4 Actual Pin5 Spec Pin5 Actual 6AF4 65 71.9 10 - 30 Neg. -11 0 0 5 - 7 AC 5.9 0 0 6AV5 0 0 5 - 7 AC 5.9 12 12 0 0 100 112 12AU7 60 70.2 1.0 Neg. -1.2 2 1.86 5 - 7 AC 5.9 5 - 7 AC 5.9 OB2 100 106.8 0 0 0 0 0 0 100 106.8                       TUBE Pin6 Spec Pin6