Collins Commercial HF · Documentation Series The Collins HF-281 Transceiver Documents, Schematics, Parts, Repair & Restoration — A Resource Guide Mike Peace VK6ADA · r-390a.net and foxtango.org Administrator · vk6ada.com.au Rev. 4.1 · October 2026 · Living document — updated…
VK6ADA Technical Papers · Amateur Radio Service Bench · Alpha Amplifiers Alpha 9500 No-Power Diagnostic Guide After a 5 V Supply Short A structured fault-isolation procedure for an Alpha 9500 that still has a healthy replacement 5 V auxiliary supply…
Software spotlight · Yaesu FT-710 710 Console: a native Windows front panel for the FT-710 CAT control, the radio’s own scope over USB, two-way USB audio and code-paired remote operation, all from a single cable. Now in free open beta.…
Collins 75A-3 · Service Note · Power Supply & Bias Locating and Replacing C-96, the Back-Bias Bypass Capacitor The one 0.1 µF paper capacitor the factory manual shows on the schematic but never calls out in the underside photograph — and…
Troubleshooting Guide · Raspberry Pi 5 · RTL-SDR Blog V4 Most Common OpenWebRX+ Issues with Raspberry Pi 5 and RTL-SDR Blog V4 Where installs actually break, in order of likelihood — the one test to run first, and a copy-and-paste…
R-390A/URR · Restoration reference The R-390A Mechanical Filters: Selection, Sources and Testing Four Collins filters, six bandwidths, one capacitor that can destroy them — and where to buy, repair and test them in 2026 The R-390A/URR gets its reputation for…
The XCB-32: Building the Rarest S-Line Transmitter A reversible Extended Crystal Board kit that converts a Collins 32S-1 into a genuine-specification 32S-2 The Transmitter Art Collins Un-Named Ask a room full of Collins collectors to name every S-Line transmitter and…
Fox-Tango Era • Yaesu Linear Amplifiers Yaesu FL-2100 / FL-2100B / FL-2100ZTuned Input Circuit: SWR Expectations & the Mica Capacitor Problem What input SWR should a healthy 572B grounded-grid amplifier show — and which of the two input capacitor styles…
Boatanchor Legends · Tribute No. 50 Living Legend · Homebrew Master Dick Benson W1QG The engineer who retired, bought a $34 FPGA board, and built the Collins S-Line all over again — in silicon, in Simulink, and in salvaged HP…
Fox-Tango Legends — No. 007 Teruhiko Hayashi JA2SVZ The Man Who Kept the Counters Counting Every Fox-Tango Legend so far has kept the hybrid era alive with knowledge — survival guides, restorations, stewardship of the club itself. Teruhiko Hayashi, JA2SVZ,…
Collins S-Line Restoration Series Waking a Sleeping Collins Restoring a 75S-3B Receiver After 50 Years in Storage Mike Peace VK6ADA · r-390a.net Administrator · vk6ada.com.au A Collins 75S-3B that has slept in a shed, attic, or estate garage since the…
Reader Question · Fox-Tango Era Keying the Ameritron MLA-2500 with the Yaesu FR‑101/FL‑101 Twins Do the twins need a keying interface to drive a vintage tube amplifier? Short answer: no — and here is why. The Question “Do I need…
Grinding Your Own FT-243 — The 2026 Edition | VK6ADA
Boatanchor Legends · Tribute No. 48 Active · CCA Technical Editor Don Jackson, W5QN The Measurement Engineer of the S‑Line — the man who put real numbers behind the Collins legend, one careful analysis at a time ✍ Mike Peace…
Thirteen current SDR receivers and transceivers, compared for one thing that matters most to those of us who still copy Morse by ear and chase weak SSB DX: HF CW and SSB receive performance. The grid rates each unit, identifies…
Boatanchor Bench Notes · Sweep-Tube Hybrids Tempo One / Yaesu FT‑200: Chasing Down “No RF Output” A systematic bench walk-through for the hybrid FT-200 family (Henry Tempo One, Yaesu FT-200, Sommerkamp FT-250) — how to read the symptoms, isolate the…
Reader Question · Fox Tango International Why Does My FT-2000D Only Make 100 Watts? Diagnosing the half-power Yaesu FT-2000D — the 50 V PA rail, the SD2931 finals, ALC drift, and the misidentification trap. “I have a Yaesu FT-2000D that is supposed…
A complete electrical & mechanical rebuild reference Hammarlund Restoration Series Hammarlund SP-600 JX-1 A complete electrical & mechanical rebuild reference Signal Corps R-274A/FRR · Hammarlund Model 31406-1 · by Mike Peace VK6ADA / r-390a.net Administrator The Hammarlund SP-600 is one…
Reader Question · from Rich, WA6KNW Driving a Collins KWM-2A or 75S-3B with an Electronic Specialty Products DDS VFO Q: “Does anyone have the manual for hooking up the Electronic Specialty Products DDS VFO (the N3ZI DDS-based unit) to a…
KWM-2A Clinic: When the Preselector Peak and Grid Drive Peak Don’t Agree A good question landed on the reflector recently from Lenny, WB6QAZ, who is bringing a round-emblem KWM-2A back to life. The radio is working well on both receive…
Yaesu FT-101E — Parts Substitution & Sourcing Reference Common failure points, modern equivalents and procurement notes for the FT-101E hybrid transceiver (12BY7A driver + 2×6JS6C finals; otherwise solid-state, dual conversion: 5 MHz 1st IF, 9 MHz VFO, 3.18 MHz 2nd IF). 20 Tracked Parts 7…
VK6ADA Technical Reference · Boatanchor Files The Collins R‑389, R‑390 & R‑390A Development, deployment, and a practical operator’s guide to the finest HF receivers of the vacuum-tube era — written for amateur radio operators and shortwave listeners, fact-checked against the…
Boatanchor Legends — A Tribute Series Carol Maher, W4CLM The keeper of the Fox Tango flame — who took a dormant newsletter club and built it into the definitive online home for Yaesu owners the world over. Some legends of…
Boatanchor Legends — A Tribute Series Milton Lowens, WA2AOQ · N4ML The retired engineer who answered one radio’s design flaw by founding the most influential users group in amateur radio history — and proved that one man, one typewriter, and…
Boatanchor Legends · Tribute No. 47 Silent Key Glen E. Zook, K9STH First Article at Seventeen, and Six Decades Without Stopping Silent Key 22 July 2020, Richardson, Texas First Licensed as a teenager, K9 district (Indiana) Business Z-Communications Company Website…
Boatanchor Legends · Tribute No. 46 Silent Key Dennis L. Brothers, WAØCBK From the Cedar Rapids Factory Floor to America’s Only Certified Collins Repair Center Born 9 February 1943, Kimball, Nebraska Silent Key 16 November 2024, age 81 Business Western…
Boatanchor Legends · Tribute No. 45 Former President · Collins Collectors Association Bill Carns, N7OTQ / KØCXX KØCXX Trustee, Longtime Editor of the Signal, Keeper of the Wimberley Shack Education BSEE 1964, MS Plasma Physics 1965, U. of Illinois First…
Boatanchor Legends · Tribute No. 44 Co-Founder · Collins Collectors Association Jay Roman, KBØATQ The Third Founder, and the Voice that Put the CCA Into Print First CCA Net Check-in 30 December 1990 CCM Founding Publisher June 1991 Original Board…
Boatanchor Legends · Tribute No. 43 Silent Key Bud Whitney, K7RMT “K7 Rocky Mountain Time” — The Bench That Kept the Collins Fleet Alive Born 24 October 1919 Silent Key circa 2010–2012 Callsign Meaning K7 Rocky Mountain Time Workshop Wimberley,…
Boatanchor Legends · Tribute No. 42 Active · Collins Engineer Rod Blocksome, KØDAS Collins Engineer, Historian, and the Man Who Brought a KWM-3 to Dayton First Licensed 1960 as KNØDAS Education BSEE 1968, MSEE 1973, Kansas State Career 42 years,…
Boatanchor Legends · Tribute No. 41 Silent Key Warren B. Bruene, W5OLY The Quiet Engineer Who Made Single Sideband Practical Born 1916, Iowa Silent Key 28 September 2013 Earlier Call WØTTK Home QTH Richardson, Texas If you have ever spoken…
Boatanchor Legends · Tribute No. 40 Silent Key Bill Wheeler, KØDEW The Quiet Founder of the Collins Collectors Association Born 18 July 1939 Silent Key 17 April 2020 First Licensed 1956 as KNØDEW Home QTH Lebanon, Missouri On a Sunday…
ARRL Year of the Club · 2026 Club QSO Party The operating event designed FOR clubs, BY clubs The ARRL has officially declared 2026 the Year of the Club, and a brand-new on-the-air event has been launched specifically to energise…
Collins KWM-2 / KWM-2A Field Service Some KWM-2 / 2A Tricks A re-issue and enrichment of the January 2016 CCAE field-service article by Georges Ricaud, F6CER (CCAE #098), with primary-source cross-references for the Collins Collector community. Front panel of the Collins KWM-2A — photograph…
GPS-disciplined crystal channels for the Hammarlund SP-600-JX Bringing parts-per-billion frequency stability to a 1950s spy-radio classic using a $18 programmable crystal module and a GPS receiver The Hammarlund SP-600-JX is one of the great communications receivers of the vacuum-tube era…
Capacitor Selection for Vintage Receiver, Transmitter, and Transceiver Restoration A practical reference for choosing replacement capacitors in premium HF tube equipment — from receivers like the R-390A and SP-600, through transmitters like the 32S-1 and Apache TX-1, to transceivers like…
Low-Noise Resistor Selection for Vintage Receiver, Transmitter, and Transceiver Restoration A practical reference for choosing replacement resistors in premium HF tube equipment — from receivers like the R-390A and SP-600, through transmitters like the 32S-1 and Apache TX-1, to transceivers…
The Boatanchor SDR Integration Series: Index and IF Buffer Amplifier Reference A consolidated index to the five SDR integration articles, plus a shared technical appendix on the buffered IF tap that most of them depend on. Over five companion articles,…
Choosing an SDR for the Collins KWM-2A Transceiver The fifth in the Boatanchor SDR series — and the receiver Collins already built with external-receiver integration in mind. Companion articles: R-390A, Hammarlund SP-600, Collins 51S-1, and Collins S-Line 75S-1 / 32S-1…
Choosing an SDR for the Collins S-Line Station: 75S-1 Receiver and 32S-1 Transmitter The fourth in the Boatanchor SDR series — and the first to cover a complete transmitting station rather than a single receiver. Companion articles: R-390A, Hammarlund SP-600,…
Choosing an SDR Front-End for the Collins 51S-1: Factory Outputs, Foresight, and Mechanical Filters The third in the Boatanchor SDR series — and the easiest of the three receivers to integrate with a modern spectrum display. Companion articles: This piece…
Choosing an SDR Front-End for the Hammarlund SP-600: Variants, Architectures, and Companions A variant-aware guide to pairing the Hammarlund Super-Pro 600 with a modern spectrum display — because the SP-600 you own may not be the SP-600 the other fellow…
Choosing an SDR Front-End for the R-390A: A Comparison Matrix A field guide for pairing the Cold War’s finest analog HF receiver with a modern spectrum display. The R-390A/URR was the most precise general-coverage HF receiver the US military ever…
RFI Analysis & Mitigation Engineering Guide VK6ADA — Boatanchor & Solid-State Technical Library Collins HF-380 Transceiver RFI Analysis & Mitigation Engineering Guide Internal emitters, external ingress paths, ferrite selection, and installation-grade RFI engineering for the military/commercial variant of the KWM-380.…
Collins Solid-State Restoration Series · Commercial / Government Variant Collins HF-380 Transceiver — Tantalum Capacitor Replacement Reference Guide A risk-prioritised service reference for the ~200-unit commercial/military variant of the KWM-380, with specific attention to the high-duty-cycle service profile that distinguishes…
Boatanchor Legends · Tribute Series Wayne Spring W6IRD · 1949–2025 Silent Key The west coast’s master of the Collins KWM-380 and HF-380, a Southern California DX Club president, and one half of ham radio’s most devoted husband-and-wife restoration team. Wayne…
Spectrum Pollution · Advocacy Brief · April 2026 Starlink and the Silent Assault on the Low-Frequency Radio Spectrum How Unintended Electromagnetic Radiation from LEO Mega-Constellations Threatens Radio Astronomy, Weak-Signal Work, and the DX-er’s Night Sky — and What Amateur Radio…
KWM-380 Tantalum Capacitor Replacement Reference Board-by-Board Location Guide, Risk Assessment & Replacement Recommendations Mike Peace VK6ADA • r-390a.net • vk6ada.com.au • April 2026 This reference accompanies the Collins KWM-380 RFI Analysis & Mitigation Guide. A site visitor asked for a…
COLLINS KWM-380 RFI Analysis & Mitigation Guide A Comprehensive Engineering Reference for Reducing Noise Floor and Improving HF Signal-to-Noise Ratios Mike Peace VK6ADA • r-390a.net • vk6ada.com.au • April 2026 • Rev 1.0 1. Introduction The Rockwell Collins KWM-380 (introduced…
Avionics History — Cold War Electronic Warfare The AN/APR-9B and AN/APA-70C on the AF-2W Guardian: Passive Radar Homing in Cold War ASW How the Grumman Guardian’s hunter variant used AIL/Collins electronic countermeasures equipment to detect, bear on, and home toward…