Vintage Ducon 1MΩ Linear Taper Potentiometer
1 Megaohm Linear Control | 400K Loudness Tap | Dual NO/NC Rotary Switch
👨🛠️ Bench Verification & Technical Condition
Up for sale is a rare, premium New Old Stock (NOS) vintage Ducon Australian-Made 1 Megaohm linear potentiometer. This highly specialized component features an integrated physical 400K Loudness Tap (4th terminal node) and a heavy-duty rotary power switch built right onto the rear casing. It features a long 1/4" (6.35mm) flatted D-shaft, meaning any classic set-screw style knob will mount perfectly. The shaft can easily be cut down if your chassis depth requires it.
- Specialized NO/NC Rotary Switch: Heavy-duty switch contacts rated at 2A 250VAC / 10A 12VDC. Directly bench-verified via digital multimeter: one pole configuration acts as Normally Open (NO) and the second pole configuration acts as Normally Closed (NC), switching states in perfect harmony when rotated clockwise past the initial firm detent click.
- Pristine Track Health: Beautifully gradual, smooth linear resistance progression across the carbon track, dropping down to a clean 0.3 Ω minimum floor when turned fully counter-clockwise.
- Technical Verification Service: Because vintage components can naturally experience minor track drift over decades of warehouse storage, resistance values may vary slightly across this batch. To guarantee absolute precision for your vintage audio restoration, I will personally bench-test your exact allocated unit on a digital multimeter before dispatch and message you its precise measured values.
• Nominal Carbon Track Resistance (Pins 1 to 3): 1MΩ Nominal (Reference unit benchmarks at 0.998 MΩ)
• Center Loudness Tap (Pins 1 to 4): ~400kΩ Nominal (Reference unit benchmarks at 491 kΩ)
• 50% Rotation Mechanical Midpoint: Smooth Linear Curve Progression (Reference Unit measures at 450 kΩ)
🔥 MOUNTING HARDWARE NOTE: I have sold several of these already. Please note that ONLY the next 2 buyers will receive the unit complete with its original vintage mounting hex nut and washer. Once those 2 are gone, the remaining units will ship without mounting hardware!
📊 Verified Component Specifications
| Brand / Manufacturer | Ducon (Made in Australia) |
| Factory Casing Stamp | 2110 DUCON 1MEGT400K PSS 057 |
| Resistance Value (Nominal) | 1 MΩ (1 Megaohm) Track |
| Taper Architecture Profile | Linear Taper Sweep (~50% Midpoint approx. 500 kΩ)
|
| Loudness Tap Resistance | Integrated 400K Centre-Track Tap (Individually Verified) |
| Integrated Switch Rating | Rotary Twist Switch | Dual Action NO/NC Pole Circuitry | Stamped Terminals 1-2 & 3-4 | Rated 2A 250VAC / 10A 12VDC |
| Shaft Profile & Dimensions | 1/4" (6.35mm) Long Metal D-Shaft with Flattened Edge |
| Era & Origin / Condition | Classic Vintage Stock | Made in Australia | New Old Stock (NOS) |
📻 Vintage Electronics Overhaul Target
This historic Australian component is perfect for authentic radio overhauls and custom tube builds:
- Classic Valve Radios: An excellent drop-in historical match for mid-century Australian valve radios utilizing Ducon architectures.
- Tube Guitar & Bass Amps: Robust construction, professional NO/NC utility paths, and high-voltage switch ratings make this a fantastic choice for specialized vintage amp repair or low-frequency tone tracking circuits.
- Alternative Switch Configurations: I have the interchangeable push-pull version of this Ducon switch body listed separately. Check my other listings if your circuit requires it!
📮 Combined Shipping Policy
Clearing out multiple vintage assets from your workspace project bins? I will gladly manually combine shipping costs across all active listings to save you money on postage. Please add your items to your cart and request a final total before making your payment so I can issue an adjusted invoice based on the true package size and weight.
⚠️ Vintage Electronics Disclaimer
This item is a premium New Old Stock (NOS) component from an accumulation of classic workshop stock. While it has been cleanly bench-tested to confirm total resistance, linear curve tracking, and perfect power switch continuity, vintage electrical components are sold as-is without modern commercial warranties. Please review all dimensions and layout pin formats closely before purchasing.