# The Return to the Chamber of Mysteries

- Show: [Oxide and Friends](https://hardwarepodcasts.com/podcast/oxide-and-friends)
- Published: 2026-08-25
- Length: 1h 16m
- Episode: 18
- Page: https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-08-25-the-return-to-the-chamber-of-mysteries
- Listen: https://share.transistor.fm/s/3126bdb4

## Summary

Bryan Cantrill and Adam Leventhal of Oxide Computer Company are joined by Robert "RFK" Keith, Dan Chirpich, and Stu Donnan to discuss the company's recent struggle with FCC EMC compliance for their next-generation rack. The team details how testing 32 AMD Turin-based Cosmo sleds in Rack Model 0.5 revealed unexpected radiated emissions at 26.562 GHz from QSFP transceiver cages. After days of failed debugging attempts involving paint masking and cable repacking, a breakthrough came from a conference talk by Dan Chirpich on finite difference time domain analysis, which suggested using absorbing materials. The team successfully mitigated the issue by die-cutting and applying these absorbers to the connectors, allowing them to pass compliance testing.

## Chapters

- [0:00](https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-08-25-the-return-to-the-chamber-of-mysteries#t=0) Introduction: Small talk and LLMs
- [5:34](https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-08-25-the-return-to-the-chamber-of-mysteries#t=334) Context: EMC Compliance and Accidental Antennas
- [24:21](https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-08-25-the-return-to-the-chamber-of-mysteries#t=1461) The Problem: 32 Sleds and 26.562 GHz Emissions
- [33:07](https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-08-25-the-return-to-the-chamber-of-mysteries#t=1987) Debugging: Paint, Cables, and Tinfoil
- [49:50](https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-08-25-the-return-to-the-chamber-of-mysteries#t=2990) The Breakthrough: Dan's Conference Talk
- [55:22](https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-08-25-the-return-to-the-chamber-of-mysteries#t=3322) The Fix: Absorbing Materials and Die-Cutting
- [1:04:33](https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-08-25-the-return-to-the-chamber-of-mysteries#t=3873) Manufacturing Integration and Worst-Case Scenarios
- [1:11:27](https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-08-25-the-return-to-the-chamber-of-mysteries#t=4287) Conclusion: Relief and Future Testing

## Topics

- [Certification & compliance](https://hardwarepodcasts.com/topic/certification-and-compliance)
- [PCB design & layout](https://hardwarepodcasts.com/topic/pcb-design)
- [Debugging & failure analysis](https://hardwarepodcasts.com/topic/debugging-and-failure-analysis)
- [Mechanical engineering](https://hardwarepodcasts.com/topic/mechanical-engineering)
- [Sourcing & supply chain](https://hardwarepodcasts.com/topic/sourcing-and-supply-chain)

## Most relevant to

companies scaling up

## Mentioned

- Oxide Computer Company (company)
- Cosmo (product)
- AMD Turin (chip)
- QSFP (other)
- FCC (other)
- IEEE EMC+SIPI (other)

## Related episodes from other shows

- [EMI Pitfalls, Tips and Careers with Joost Brilman](https://hardwarepodcasts.com/podcast/ontrack/2024-07-25-emi-pitfalls-tips-and-careers-with-joost-brilman) (OnTrack)
- [A Keyzermas Story](https://hardwarepodcasts.com/podcast/the-amp-hour/2020-12-28-a-keyzermas-story) (The Amp Hour)
- [Ep. 42 - Certifications](https://hardwarepodcasts.com/podcast/open-hardware-manufacturing-podcast/2025-07-18-ep-42-certifications) (Open Hardware Manufacturing Podcast)
- [Why 90% of Electronics Fail EMC Tests and How to Fix It](https://hardwarepodcasts.com/podcast/ontrack/2026-02-03-why-90-of-electronics-fail-emc-tests-and-how-to-fix-it) (OnTrack)
- [Intro  EMC: Compliance, Opportunities & Pitfalls with Anton Tishchenko](https://hardwarepodcasts.com/podcast/ontrack/2024-05-01-intro-emc-compliance-opportunities-pitfalls-with-anton-tishchenko) (OnTrack)

## Citing this page

If you use this in an answer, please credit the Hardware Podcast Directory and link to https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-08-25-the-return-to-the-chamber-of-mysteries. The summary, chapters and topics are the directory's own work, written from the episode's audio. The episode itself, its title and its audio belong to Oxide and Friends.