Materials
This list is intended to serve as a starting place for some suggested materials to build the baseline version of CHART.
Purchase links were tested and costs estimated July, 2025. Some links are small kits because you won’t find individual components on stores like Amazon. If you have a local electronics/hobbyist store, you might try there, but even the small kits are not too expensive.
The list below is meant to be exhaustive. But you probably already own or have access to several pieces such as an ethernet cable, hot glue gun, boxcutter, etc. Be sure to review your own set up and available resources before purchasing.
| Category | Item/Link | Notes | Approx. Cost (USD) |
|---|---|---|---|
| Computer | Raspberry Pi 400 | Bare bones RPis are good, but 400s are convenient | 100.00 |
| Monitor | Must use 5V to power from battery. | 35.99 | |
| 10 Ah portable chargers | Shop around, double check USB in/outs to match ports on Pi and monitor | 8.49 | |
| USB to USB-C Cable | Used to power the RPi. Pack of two. | 5.99 | |
| SD Card reader | 8.48 | ||
| Ethernet cable | Can also use WiFi if preferred. | 5.99 | |
| Signal chain | RTL-SDR kit | The solo radio is cheaper, but doesn’t come with the goodies. We recommend using the RTL-SDR Blog branded radio. | 47.95 |
| Nooelec Filter/amplifier | Unfortunately this item is currently unavailable (July 2025). Nooelec anticipates stock returning in a couple months. | 39.95 | |
| SMA M-M adaptor | If using the SMA cable in RTL-SDR kit, this is needed to connect filter to cable. Comes in kit of five pairs | 6.01 | |
| SMA right angle | Connects panel mount to filter. | 4.79 | |
| SMA panel mount connectors | Pack of five | 7.99 | |
| Horn | Cardboard | 4 36” x 48” sturdy sheets. Refrigerator boxes found behind your local appliance store work well. | – |
| Heavy duty aluminum foil | Available in most supermarkets, etc. Need about 75 square feet | 6.89 | |
| Aluminum foil tape | Available at most hardware stores. | 4.42 | |
| Tools | Hot glue gun and glue sticks | 16.26 | |
| Boxcutter | Find at any hardware store. | 4.43 | |
| Soldering iron | Cheap irons like this exist, and you only need one solder joint for this project. However, high quality irons are very useful if you want to invest or if you have access to one. | 12.05 | |
| Digital multi meter (DMM) | Optional but handy for checking connectivity. Same as solder iron - quality ones are more expensive but worth an investment. | 12.59 |