015-027/Repairs

These power supplies have the positive side grounded, which can introduce a ground loop into sensitive measurements. It would be good to take a hint from the supplies for the Tektronix Type 134, where one side of the supply is held close to ground by a pair of anti-parallel diodes, instead of a direct ground.

For added safety, take another hint from the 134 power supplies and install a 100 mA fast acting fuse in the hot lead to the transformer primary. This will blow if the transformer develops a primary to secondary short, which would otherwise be dangerous.

I have added both features to my 015-027, and my Type 131 still works perfectly.