Essential Ph8 Parts Update Spring 2009

for experiment 11:

In exp. 11, you'll build a variable spark gap. The parts to check now in your kit are the two brass thumb tacks and the wooden clothes pin. (It's the kind with a spring, and it opens and closes.)

The thumb tacks should have heads that are smooth. Many kits have heads that are embossed with a little design. Throw those out! And get new ones. (See your TA and/or the parts cabinet.) The new ones also have longer shafts, which is essential for attaching the relevant wires.

The clothes pin should have four holes drilled into it: a tiny one in each of the gripping ends and a larger one in each of the ends you squeeze. These larger holes will allow the tiny 4-40 machine screw in your kit to slip through.

Many kits have undrilled clothes pins. If that applies to you, get one that is drilled.

for experiment 13:

All kits were packed with the wrong 14-pin IC (integrated circuit). Throw it out! (Do not throw out the 8-pin IC, the 8-pin IC holder, or the 14-pin IC holder.) Get a new 14-pin IC. Its part number should contain 74HC05. (The crucial part is the HC; the old one was 7405.)