• https://raspberrypi.stackexchange.com/questions/74482/switch-out-the-x1-oscillator-on-a-rpi-2-3/109074#109074

Made an initial attempt on the evening of 2023-03-26 on a Pi 2 B. Drop in replacement is working surprisingly well right off. Have not performed any longitudinal testing yet, but initial tracking numbers are positive.

Pi 2 B with replaced XO	Pi 2 B with stock XO

• https://ozzmaker.com/testing-points-raspberry-pi/

PP3 GND
PP4 GND
PP5 GND
PP6 GND
PP7 5V after polyfuse
PP8 3V3
PP9 1V8

Marked AEL19.2

• http://www.farnell.com/datasheets/2860337.pdf

• IQXT-205-3-18 or
• TXETBLSANF-19.200000

Before I do this swap, I need to get a benchmark of (at least) two identical Pis so I have a baseline of their performance in stock configuration. These systems need to be as identical as possible, both in terms of software load out as well as their physical deployment.

• OS - Alpine Linux 3.17
• Timekeeping/measurement - chrony

Configured to be as light and slim as possible.

This will be an isolated test, no

Meanwell 5v PSU powering both Pis - “back feeding” through the 5v pin on the 40p header. AC PSU connected to a UPS to protect against brownouts or extended outages.

Both Pis enclosed in a single styrofoam enclosure, as close to each other as reasonable. Placed in a location that is as temperature stable as possible (no direct sunlight, no temp swings from HVAC adjacency, etc.)

• https://sourceforge.net/p/raspberry-gpio-python/wiki/PWM/
• https://gist.github.com/boseji/7296415

#!/usr/bin/python
#####
# This tool generates PWM on GPIO10 (Pin 19)
# with 20% Duty Cycle at 1kHz
######

import RPi.GPIO as GPIO
from time import sleep

GPIO.setmode(GPIO.BCM)
GPIO.setup(10,GPIO.OUT)
p=GPIO.PWM(10,1140)
p.start(20)
sleep(3600)
GPIO.cleanup()
exit()