Dr. James A. Moorer:
A Boat Anchor Radio Legend
How an Academy Award–winning digital audio pioneer became one of the most prolific archivists and restorers of Cold War–era military receivers
There are collectors who accumulate vintage receivers, and there are technicians who restore them. Then there is James A. Moorer — a man who does both while simultaneously scanning, annotating, and publishing the original military service manuals that make restoration possible for everyone else. His website at jamminpower.org has quietly become one of the most important reference archives in the boat anchor community, an indispensable resource for anyone working on Hammarlund SP-600, Collins R-390, and a constellation of other Cold War–era military receivers.
What makes Moorer’s contribution so remarkable is the depth of expertise he brings from outside the amateur radio world. By profession, Dr. Moorer is an internationally recognized figure in digital audio and computer music. He holds a Ph.D. in Computer Science from Stanford, dual bachelor’s degrees from MIT in Electrical Engineering and Applied Mathematics, and a career resume that includes Lucasfilm, IRCAM in Paris, Sonic Solutions, and Adobe Systems. He created the iconic THX “Deep Note” cinema audio logo — a composition whose distinctive power comes from his deliberate use of just-intonation tuning, a detail that remains widely misunderstood. He has won an Emmy Award, an Academy Award for Scientific and Engineering Achievement, and the Audio Engineering Society’s Silver Award for lifetime achievement.
Yet when you visit his website, the boat anchor pages are given equal billing with all of those professional accomplishments. The navigation bar places “Boat Anchors” right alongside “Resumé” and “Technical Articles” — a quiet testament to how seriously he takes this avocation.
The Hammarlund SP-600: A Lifelong Passion
The heart of Moorer’s boat anchor work centers on the Hammarlund SP-600 Super-Pro. He has described the receiver as having “so much personality” that he finds it irresistible, even acknowledging it may not have been the absolute best performer of its era. As a boy he had heard of the famed Super-Pro but never knew anyone who owned one — in the 1950s the $1,200 price tag placed it well beyond the reach of most radio enthusiasts.
Today, Moorer has restored and documented more than a dozen SP-600 receivers, many of which he sold on eBay with full restoration narratives. His SP-600 page provides an extraordinary level of technical detail: the differences between the diversity receivers (JX-17) and standard models, the history of the “7-wire” RF deck with its incompatible screen supply topology, guidance on ordering custom crystals for the Frequency Control Unit from International Crystals, and even a JavaScript frequency calculator embedded right in the page.
“Even with my fading eyes, I can see all the parts in these receivers. You can actually fix them!”
His practical restoration guides cover techniques that range from the mechanical — cleaning a chassis with Simple Green and distilled water, protecting ferrite cores from soap infiltration, reassembling the SP-600 gear train — to the deeply electrical, including annotated wiring diagrams where he has added component values next to the original part numbers for easier troubleshooting.
The Manual Archive: A Gift to the Community
Perhaps Moorer’s single greatest contribution to the boat anchor community is his painstaking scanning and digital preservation of original military service manuals. Anyone who has tried to restore a vintage military receiver knows that without schematics and alignment procedures, the task is nearly impossible. Original manuals are scarce, expensive, and deteriorating. Most existing scans found online are of poor quality — half-tone photographs rendered as unreadable black blobs.
Moorer has invested extraordinary effort to produce high-resolution scans with manually de-screened halftone images, because as he notes, automatic descreening does not work very well. His archive includes complete manual sets for virtually every variant of the receivers he works on. The scope of this effort is staggering:
| Receiver | Manuals Scanned | Notable Inclusions |
|---|---|---|
| SP-600 | 14+ documents | Issues 1–6; TM 11-851 (390 MB, six 14″×60″ fold-out schematics); complete Air Force AN/TO manual set for JX-17, JX-21; annotated wiring diagrams |
| R-390 / R-390A | 7 documents | TM 11-856 (180 MB, the only manual with wiring diagrams for every module); TM 11-856A; original IRE and GE Review engineering articles used in the R-390 design |
| R-1051 | 5 documents | NAVELEX maintenance manual; R-1051B, D, and H variant manuals (up to 383 MB); module repair handbook |
| BC-348 | 10 documents | Manuals for E, H, B, J, S variants; annotated schematics; complete tube data sheets from RCA HB-3; surplus conversion manual excerpts |
| SCR-578 | 3 documents | Gibson Girl rescue transmitter Bendix preliminary manual; complete AN maintenance instructions including kite, balloon, and raft documentation |
The TM 11-851 alone — the definitive Army manual for the SP-600 — runs to 195 pages of text with six enormous fold-out schematics. Moorer not only scanned the entire document at high resolution but also reformatted each fold-out as overlapping 11×17 sheets that can be printed at any copy shop and taped together. For readers without means to download the massive files, he has offered to mail printed, comb-bound copies.
The Receivers: Moorer’s Fleet
Beyond the SP-600, Moorer maintains detailed pages for each receiver family in his collection, approaching each with the same mix of engineering rigor, historical curiosity, and candid personal opinion that defines his writing style.
Moorer admires the incredible engineering while noting the R-390 was classified until 1968. He scanned rare GE Review and IRE Proceedings articles used in its original design — documents most restorers have never seen. He also conducted a “Great Salvage Expedition” recovering approximately 60 receivers, a lifetime supply he has been steadily restoring and selling.
A transistorized receiver that still weighs 70 pounds and retains two vacuum tubes in the RF amplifier — a design choice Moorer attributes to static and ECM resilience. He provides detailed module-level documentation and has preserved scarce Navy manuals that were systematically destroyed after decommissioning.
Dating from the mid-1930s, these receivers flew in B-17s and B-24s. Moorer bought original manuals at extraordinary prices to produce high-quality scans with legible halftone images — something no other scan had achieved. He documents every sub-variant from the E through the R.
A unique Technical Materiel Corporation receiver from the Navy’s Remote Control Receiver System, designed for remote unmanned operation from separate control panels — an architecture decades ahead of its time.
A German-made receiver with separate USB/LSB outputs, unusual 3-blade connectors, and engineering quality Moorer finds remarkable. One of the rarer receivers in the boat anchor world.
The iconic hand-cranked emergency rescue transmitter carried by Allied bomber crews — complete with kite, balloon, and survival raft. Moorer scanned the original Bendix glossy-page instruction manual and multiple maintenance handbooks.
He has also documented the Technical Materials Corporation CV-591A/URR single-sideband adaptor, which connects to the SP-600’s IF output to provide SSB reception so clear that he writes it sounds better than much AM. The device uses ten tubes where three might suffice — a design philosophy he characterizes with evident delight as being totally over-engineered.
The Engineer’s Approach
What distinguishes Moorer from other collectors and restorers is the engineer’s perspective he brings to every aspect of the work. His page on thermal noise and receiver sensitivity synthesizes his own analysis with contributions from the late Dallas Lankford, offering a resource that sits at the intersection of practical radio restoration and fundamental RF engineering.
His observations on the SP-600 AGC structure in the diversity receivers reveal deep circuit-level understanding — noting that injecting AGC voltage into the 6BE6 first mixer is problematic because the tube was not designed for variable-mu operation, leading to easier overloading on strong signals. These are not casual opinions but conclusions drawn from hands-on restoration of a dozen or more units.
On the BC-348, he offers nuanced analysis of why its 915 kHz intermediate frequency was a deliberate engineering choice to improve image rejection compared to the standard 455 kHz IF, and how deliberately low RF stage gain reduces intermodulation distortion from strong-signal nonlinearities — insights that demonstrate a working understanding of receiver design principles at a level few restorers can match.
A Note on the R-390 Salvage Expedition
One of the more extraordinary stories on the site is what Moorer calls “The Great R-390/R-390A Salvage Expedition” — the acquisition of approximately 60 receivers, of which roughly 20 are the rarer R-390 (not R-390A). He estimated that five could be put into good working condition relatively easily, with perhaps twenty more restorable with varying degrees of effort. The collection included ample quantities of every module type, including coveted IF strips with four mechanical filters. He has documented this trove photographically and has been methodically working through the collection, restoring units at his own pace and making them available to other enthusiasts.
A Legacy in Two Worlds
James Moorer occupies a unique position in the boat anchor community. His professional world — the rarefied intersection of DSP theory, film post-production, and computer music — could not seem further from the world of hand-wound coils and stagger-tuned IF strips. Yet these worlds share a common thread: a deep respect for the craft of engineering, a belief that understanding how something works is as important as making it work, and a commitment to documenting knowledge so that others can build upon it.
His published technical articles — covering topics from phase vocoders to prime-residue erasure codes — are available alongside scanned 1943 maintenance manuals for bomber liaison receivers. His doctoral dissertation on computer transcription of music sits one navigation click away from instructions for washing an SP-600 chassis with a garden hose. This is not a contradiction. It is the mark of a genuinely curious mind, one that sees no hierarchy between inventing an Oscar-winning audio process and ensuring that a 75-year-old receiver hums to life one more time.
“Generally there is nothing left of a radio but the unit itself. It is quite rare that any information from the engineers actually survives.”
For the Collins and Hammarlund communities in particular, Moorer’s freely shared manual archive represents an irreplaceable resource. Manuals that were once available only by lucky finds at hamfests or through fading photocopies are now preserved at high resolution and available to anyone with an internet connection. Every SP-600 restorer who can read a component value on a wiring diagram, every R-390 enthusiast who can follow a module-level troubleshooting procedure, every BC-348 owner who can identify the correct tube types for their specific variant — all of them owe a debt to the quiet, meticulous work documented at jamminpower.org.
In an era when boat anchors are, as some have lamented, increasingly “sold by the pound,” James A. Moorer has done more than most to ensure that the knowledge required to keep these magnificent receivers alive will outlast any individual restorer’s workshop. That is the work of a true boat anchor legend.