Manhattan Lamp Works
324 West 42nd Street, New York, New York, USA
Last seen: 23-May-1925
Brand(s): Belltone, Clearatone, Operatone
Manhattan Lamp Works appears to have been a manufacturer of tubes labeled under several brands. Their advertising all appears in a tiny slice of time in early 1925. Given that all ads show BBNT tubes, we can place them squarely in this time frame.
The Belltone ads show 'Clearatone' on the tube, the Clearatone ad shows Radio Tube Laboratories, 296 Broadway, NYC
I have placed the Clearatone tubes with Manhattan, since their photo seems ubiquitous to these ads.It seems unusual that Belltone sells for $1.75 14-Mar-1925, and by April they are marked down to $0.95. It seems their initial price point was too high and lowered almost immediately after the first advertisements.
I have not run across any examples of these tubes, and would love to hear from anyone with examples.