The search returned 2 articles:

  1. October 2018: Project: GPS-synched Frequency Reference Pt.1 by Tim Blythman, kits: SC4237, PCBs: 04107181, 7 shop items [print issue] [online issue]
  2. November 2018: Project: GPS-synched, lab-quality frequency reference (Part 2) by Tim Blythman and Nicholas Vinen, kits: SC4762, PCBs: SC 04107181, 7 shop items [print issue] [online issue]