Unfortunately vendors close their doors or modify the design of components. As readers report problems to me because of these types of changes I've posted some solutions below.

Scary Pumkins

A reader had trouble finding the PNA4602. This type of IR detector is stocked by stores that specialize in robot projects such as Reynolds Electronics or Solarbotics.

I found the ISD1110 at Jameco.

Infrared Go-Kart

A reader mentioned that Reynolds Electronics had revised the Tiny-IR IC.

If you have the newer IC's, the Tiny-IR-II, you should be easily use it in the circuit. Here's my ideas from looking at the details of the new IC:

You should be able to use the TinyIR II, just only use three of the five pins that you can connect button switches to.

While I haven't used the new IC the following connections should work according to the schematic from Reynolds Electronics. No guarantees since I haven't tried this IC myself.

For the Encoder:

Pin 1 is still connected to the positive side of the voltage regulator.
Pin 2 is connected to the LED and resistor in series with ground.
Pins 5, 7 and 6 can be connected to the button switches, just add the 100 kohm resistor they show from each pin to the negative side of the battery pack..
Pins 3 and 4 aren't needed, just wire a 100 kohm resistor from each pin to negative side of the battery pack.

For the Decoder:

It looks like the only change is that pins 2 and 3 are not needed. Since the Reynolds write up says that the outputs default to ground you should be able to leave these unconnected.

Couch Pet-ato

The company that made the tilt sensor shown in the book is no longer selling products. I found a tilt sensor at Mouser, part number RBS151100 that you should be able to use in place of the part shown in the book. This part has four leads, instead of two leads seen on the other part. However the datasheet shows that this part functions as a two lead device with spare leads connected together on the circuit board.

Surfing the Airways

A reader reported that the Ocean Electronics website where I purchased the ZN416E is out of business. In looking for other suppliers that stock the ZN416E I can't find one that I would recommend. Looking for a replacement part I found that there are two parts that are supposed to be almost identical: MK484 and TA7642. They require a slightly different circuit that you can see on the datasheet for the MK484

A vendor called Electroncs123 shows the MK484 in stock at the following url

A website called Crystal Radio Supply stocks ferrite rods and variable air capacitors.

I haven't used these suppliers before, please let me know if they are prompt on shipping, etc.

General Notes

1/4 watt resistors were used to build the projects in this book unless noted in a particular project. If you have 1/2 watt resistors they can also be used. You shouldn't use 1/8 watt resistors.