Fitted with four genuine Dale NH-250 aluminium-clad power resistors:
- 8Ω
- 250W each
- 1% tolerance
Mounted in a substantial aluminium enclosure with heavy-duty binding posts, BNC monitoring connections and switching controls. There are two three-way switches on the front panel; one on either side. The central position for each switch is ‘off’, and the left and right positions select each channel independently.
Having traced the internal wiring and switch operation with a multimeter, the unit appears to have been designed as a four-channel amplifier test load for bench or workshop use. Each resistor operates as an independent 8Ω load channel, selectable via the front-panel switches. The associated BNC connections appear intended for oscilloscope monitoring while testing amplifier outputs.
The construction quality is excellent throughout, with heavy-duty internal wiring, proper chassis-mounted resistors and quality components. The aluminium enclosure also acts as a substantial heatsink for the resistor banks. This is a well thought-out build.
The use of low-tolerance Dale resistors together with substantial heavy duty internal wiring suggests the unit was carefully designed to minimise unwanted resistance and voltage loss within the load paths.
Likely suitable for:
- Audio amplifier testing
- PA amplifier servicing
- Multi-channel amplifier bench work
- General electronic load-testing applications
The resistors are chassis-mounted and air-cooled. The unit appears intended for intermittent workshop or bench testing rather than prolonged continuous full-power dissipation. Anyone intending extended heavy-duty use may wish to consider additional forced-air cooling via fans, and adding some rubber feet.
A very interesting and well-made piece of workshop / laboratory equipment, clearly constructed by somebody with good electrical engineering knowledge.
Please study the photographs carefully to determine suitability for your intended application.
