1906-1910 Marconi Magnetic Radio Detector
No Sales Tax If Shipped Outside North Carolina
Developed by Guglielmo Marconi at the turn of the last century, and based on Ernest Rutherford’s research into the hysteresis of iron, the magnetic detector used woven strands of iron wire passing through a coil-wound glass tube, in close proximity to a pair of magnets, to detect radio signals.
The example offered here, which (in fits and spurts) still runs wire through the glass tube, was purchased in Dearborn, Michigan in 1995 from the Henry Ford Museum, when the museum auctioned off the contents of its Edison Institute for the benefit of its General Collections Fund.
The detector was restored while in the curatorship of the Institute, and allegedly (at that time) it could still be used to detect radio signals, but it’s being offered here for historical purposes only, with no assurances stated or implied that it’s still suitable for radio wave detection.
Condition overall is very good. The cabinet and its beveled glass lid are original and undamaged (the side drawer is a replacement), and the magnets and pulleys are also original and undamaged. The original Marconi tag (New York) is clean and legible. The pulleys/drive wheels have the Edison Institute’s inventory number lightly written on their top side (appears to be in pencil). The Institute’s gray metal inventory tag — the inventory number matches the number on the pulleys — is affixed to the back of the cabinet.
Brass fittings and select pieces of hardware have been cleaned and polished, as has the crank. There’s limited tension from the motor as it’s wound, suggesting the end of the mainspring may have become detached from the spring barrel; nonetheless, enough spring tension can be achieved to propel the pulleys and wire for a few seconds when the crank is wound several turns.
A beautiful artifact of radio in its infancy, and a unique opportunity to own a piece of Marconi gear that seldom changes hands. With the lid closed and the crank installed, the detector measures approximately 20″ x 9″ x 9″.
The original auction lot tags from the 1995 Dearborn de-accession sale are included.