Emtron DX-3SP Linear Amplifier:Restoration & Service Guide Two FU-728F Tetrodes in Parallel • 4,000 W Carrier / 5,000 W PEP • 3,400 V DC Plate Supply • 9 Bands 160m–10m incl. WARC • Three Bias Pots (POT3 + POT10/BS1 + POT9/BS2) • Safety…
Emtron DX-4 Linear Amplifier:Restoration & Service Guide Two GU84B (4CX2500A) Tetrodes in Parallel • 4,000 W Carrier / 5,000 W PEP • 3,100 V DC Plate Supply • Separate Standalone HV Power Supply (3 Variants) • Three-Interlock Serial Safety Chain • Auxiliary Transformer in…
Henry Radio HF Linear Amplifiers:Omnibus Restoration & Service Guide All HF Tube & Solid-State Models • 2K/3K/4K/5K/8K Series • 1963–2005 • Los Angeles, California • Grounded-Grid Triodes • 3-400Z • 3-500Z • 8873/8874/8877 • 3CX1200A7/D7 • 3CX3000A7 • 5CX1500A •…
Heathkit SB-200 Linear Amplifier:Complete Restoration Guide Circuits • Cabinet • Safety • Component Replacement • Modern Upgrades • SB-201 Coverage 📝 VK6ADA Technical Papers 📅 March 2026 ⚡ 572B Triode — 600 W Class ⚠ High Voltage Equipment Abstract. The Heathkit…
Heathkit SB-220 Linear Amplifier:Complete Restoration Guide Circuits • Cabinet • Safety • Component Replacement • Modern Upgrades 📝 VK6ADA Technical Papers 📅 March 2026 ⚡ 2 kW Class — 3-500Z Triode ⚠ High Voltage Equipment Abstract. The Heathkit SB-220 is…
Community Join the Vintage AmateurRadio Restoration Group A dedicated mailing list for amateurs who restore, study, and operate vintage HF equipment — Collins, National, Hammarlund, Hallicrafters, Drake, Heathkit, and beyond. Technical advice, restoration notes, and a community that values doing…
Collins 180S-1 Jumper Plug Engineering Design | VK6ADA VK6ADA vk6ada.com.au • r-390a.net Collins S-Line — Engineering Design Document Collins 180S-1Jumper Plug Reproduction A comprehensive engineering design for fabricating reproduction jumper plugs for the Collins 180S-1 antenna tuner — including circuit…
Collins 180S-1 Antenna Tuner Restoration Guide | VK6ADA VK6ADA vk6ada.com.au • r-390a.net Collins S-Line Accessories Restoration Series Collins 180S-1Antenna Tuner Restoration Guide A complete field guide to the cosmetic and mechanical restoration of the Collins 180S-1 pi-network antenna tuner —…
R-390/URR Restoration Guide | VK6ADA VK6ADA vk6ada.com.au • r-390a.net Collins Military Receiver Restoration Series R-390/URR ReceiverRestoration Guide A complete field guide to the cosmetic and mechanical restoration of the Collins R-390/URR military HF communications receiver — covering disassembly, the critical…
R-390A/URR Restoration Guide | VK6ADA VK6ADA vk6ada.com.au • r-390a.net Collins Military Receiver Restoration Series R-390A/URR ReceiverRestoration Guide A complete field guide to the cosmetic restoration of the R-390A/URR military HF communications receiver — covering disassembly, haze gray finish specification, panel…