Cal board
About the Cal board
Cal board is an open source PCB design by naizhao, published on GitHub under the MIT license. It is a 2-layer board measuring 95 × 92 mm, with 16 components from 3 distinct parts.
By type, the board carries 12 connectors and 4 resistors.
From the project
Pilot Kit Box (ESP32-P4 Edition)
一块给 NanoVNA 用的板载 SOL 校准件 + U.FL/SMA 转接板。
生成：~/Applications/KiCad/KiCad.app/Contents/Frameworks/Python.framework/Versions/Current/bin/python3 tools/gencalboard.py 产物：kicad/cal-board.kicad_pcb 95 × 92 mm，2 层，1.6mm
U.FL 没有现成的 SOL 校准件，校准面只能停在 VNA 的 SMA 口，尾线（pigtail） 留在测量链路里。2026-09-04 实测：V4.4 板 J6 读到 11.45pF，理论只有 1.6pF， 差 7 倍，一度以为板子坏了 —— 实际是尾线没被校准掉。
同一根尾线（往返 0.55dB）：天线（|Γ|=0.04）SWR 1.083→1.089 可忽略； 开路线（|Γ|=0.885）SWR 10.84→16.40，压低了三分之一。
Cal board bill of materials (BOM)
16 components, 3 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 6 | U.FL_Hirose_U.FL-R-SMT-1_Vertical | U.FL_Hirose_U.FL-R-SMT-1_Vertical | J1, J2, J3, J7, J9, J10 |
| 6 | SMA_KHD | SMA_KHD_Vertical_THT | J4, J5, J6, J8, J11, J12 |
| 4 | 100 | R_0402_1005Metric | R1, R2, R3, R4 |
Cal board design files
The KiCad project lives in the naizhao/Pilot-Kit-Box-ESP32-P4 repository on GitHub; these links point at the commit this page was built from.
Cal board: common questions
How big is the Cal board?
The Cal board measures 95 × 92 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the Cal board?
16 components, from 3 distinct parts, with part numbers taken from the project's own BOM. The full bill of materials is listed on this page.
Where can I download the Cal board design files?
From the naizhao/Pilot-Kit-Box-ESP32-P4 repository on GitHub, which has the KiCad layout and the BOM; the links under Design files point to each one.
Can I use the Cal board design in my own project?
Yes, under the terms of its MIT license, which naizhao chose for the repository.
