Show Computer in a Box

Inside the control box: Raspberry Pi 2 Sain Sonic FM Transmitter D-Link 5 port ethernet switch Dipole Antenna cut for 97.9 FM WiFi Dongle on USB Extension cord RF Chokes on low voltage cables

Antenna: The antenna is a simple dipole antenna. Basically, its a section of coax to the transmitter with the and of the coax going to a specifically measured length of wire (standard speaker wire). The center of the coax is the main radiating element of the antenna, while the outside of the coax connection goes to a matched section acting as a base plane or counter poise wire. This allows the antenna to radiate its signal effectively with minimal SWR back to the transmitter. The antenna is hot glued into the lid of the box. The end of the coax is on the bottom right of the lid. The main radiating element wraps around the lid along the bottom, left side and along the top to be as far away from the other components as possible. The ground element wraps in the other direction along the right side of the lid, along the top and on part of the left side. The ground is not directly next to the radiating element, it is closer to the other components when the lid is closed. A Dipole calculator can be found here. My antenna is tuned for around 97.9 MHz, so each side of the dipole is about 2ft. 4 - 11/16in

Raspberry Pi 2:
This is a kit from Amazon, and the FPP image put on the chip. A thumb drive is added to store all of the sequences/music/settings. This setup is using a small USB adaptor with a standard micro-usb cord for power. A spare USB extension cable was used to move the WiFi dongle away from the Pi and the other components, so it would get a better WiFi signal.

Transmitter:
SainSonic 0.5w transmitter, with a modified antenna connector. The connector was replaced with a standard BNC connection, as apposed to the RP-TNC connector with reversed gender.

Ethernet Switch:
A D-Link ethernet switch was used for this install, but any basic ethernet switch (not hub) will do.

General Constriction:
Everything is inside a CG-1500 case. Coro board was used on both sides of the case, and components were hot glued to the coro board. RF Chokes were added to the power for the transmitter, as well as part of the antenna to keep the RF on the top of the antenna. A standard extension cord with a 3 port breakout was used to supply power to the box.