Codit

Fellow Radiophiles,

This very unusual recorder was reported in the special June 1948 Radio Craft issue dedicated to FM and Major E H Armstrong.

 

After some searching at the Google Patents site, this very similar apparatus came up in patent 2567092. Strangely, the patent assignee is the Brush Development company of Cleveland OH, not the Codit company of Chattanooga Tennessee.

I found no mention of the encryption. But the mechanical encryption is not within the apparatus but in the shape of the grooves, which could be simply off-center, or in some other wavy pattern. Even a simple phase variation between the plastic disk and the magnetic disk would make the tracks unintelligible.

 

Regards,

-Joe

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Hi Joe,

This appears to be virtually identical to a Brush model BK-503 "Mail-a-Voice" recorder except that it apparently uses a distinctive guide disk. I suspect that Brush Development Corp. probably built these for Codit to resell, since they are virtually identical. The normal guide disk on a Brush BK-503 is just a regular spiral groove which directs the record/playback arm (like a lead-screw), since the magnetic paper disk is perfectly smooth and has no other means to guide the arm. As you suggest, the Codit guide disk likely has a special wavy groove to give the record/playback arm a unique trajectory.

 

I have a BK-503 in my personal collection, and hope to upload pictures of it shortly.

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