vk6ada.com.au • Collins R-390A/URR Technical Reference Series Collins R-390A/URRAudio Output Transformer — Failure, Specification, and Substitution Options A definitive single-source reference for the R-390A audio output transformer: how to diagnose failure by DC resistance and inductance measurement, the operating point…
vk6ada.com.au • Collins R-390A/URR Community Reference • 2026 Market Report State of the R-390A Parts Market 2026Availability, Critical Scarcities, and Sourcing Strategies for Today’s Restorer A practical current-conditions survey of the R-390A parts landscape in 2026: what remains straightforward to…
vk6ada.com.au • Boatanchor Legends Series • R-390A/URR Technical Community Dr. Dallas LankfordHis Legacy and Contributions to the Collins R-390A/URR Community A focused tribute to Dr. Dallas Lankford’s technical scholarship and community service on behalf of the Collins R-390A/URR: author of…
r-390a.net • The Definitive R-390A/URR Community Reference Collins R-390A/URRTen Most Common Failures — Ranked by Community Report Frequency A data-driven ranking of the ten failure modes reported most frequently across 27 years of R-390A community documentation: the R-390 Reflector archive,…
Wei-i Li The Archivist Every technical community generates far more knowledge than it manages to preserve. Conversations happen, problems are solved, solutions are shared — and then the thread scrolls off the page and the answer that took three experts…
Clemens Stubbe Østergaard The Scholar at the Receiver The R-390A community has always attracted serious people — engineers, technicians, former military operators, and dedicated amateurs who approach the receiver with the same rigour they bring to their professional lives. Clemens…
Dr. Gerald N. Johnson — KE0KI The Engineer in the Room Most online technical communities have enthusiasts, experienced hobbyists, and the occasional retired technician. Very few have a licensed Professional Engineer with a Ph.D. in electrical engineering who shows up…
Electric Radio Magazine — Barry Wiseman N6CSW & Ray Osterwald N0DMS The Publication That Gave the Community a Voice Every technical community needs somewhere to put its knowledge down in writing — somewhere permanent, indexed, and reproducible. For the R-390A…
Bob Thomas, VE3TOU Godfrey, Ontario, Canada Founder, Treetop Circuits · SSB Adapter Designer · Licensed Amateur Since 1958 Bob Thomas, VE3TOU, is the designer and founder of Treetop Circuits — the small Ontario cottage operation that for thirteen years produced…
Boatanchor Legends: Edward Kujawski — The BAMA Archive Boatanchor Legends — A Tribute Series Edward Kujawski The Boat Anchor Manual Archive Keeper of the Manuals — bama.edebris.com Every restoration begins with a manual. Before the first capacitor is replaced, before…