The Si5351APicoBoB (short for Si5351A Pico Breakout Board) is a specialized version of the clock generator board, specifically optimized for Pico Balloons (high-altitude balloons) and ultra-lightweight amateur radio payloads.

using ASTX-H11-25.000MHZ or similar which is TCXO

## Detailed Overview:

* Purpose: The board is designed to be the frequency source for long-distance trackers and transmitters (using modes like WSPR or APRS) that fly on balloons around the world. In these missions, weight is the most critical factor for reaching the stratosphere.

* Extreme Weight Optimization: Unlike a standard breakout board, the PicoBoB is stripped down to the essentials to save every possible milligram, ensuring the balloon can stay aloft for weeks or even months.

* Hardware Design: It is based on the Si5351A synthesizer chip.

* Environmental Resilience: While compact, the design is intended to be integrated into "payload" systems that must survive the harsh conditions of high altitudes, including extreme cold and low atmospheric pressure.

* Integration: It serves as the "heart" of a radio transmitter, providing precise frequency control. Just like the other Etherkit modules, it outputs square waves that are typically filtered before reaching an antenna to ensure a clean signal.

## Summary:

This is the ultra-lightweight, mission-specific version of the Si5351A breakout. If you are building a flight controller or a solar-powered tracker where every gram of mass counts, this is the specific hardware design to use.

all credits to Etherkit Jason Milldrum NT7S