|Burroughs MO-10R / 6704
|Written by Accutron on 2007-06-20
The MO-10R is a high speed variant of the 6700, with internal 100K spade resistors and an unusual 20-pin base. The MO-10R is believed to be the fastest counting tube ever produced, with a maximum counting speed of 10 MHz. There is also a shielded variant of the MO-10R, the BD-309, which resembles the large, shielded BD-301 (shown above). The internal spade resistors are mounted at the top of the tube, between the upper mica sheet and the getter.
Criteria for Selection of the Magnetron Beam Switching Tube as a Circuit Component (PDF)
Though it resembles a 6700, the MO-10R is an unusual beam-switching tube with internal spade resistors. Minimizing spade lead capacitance is critical to obtaining high counting speeds in beam switching tubes; most driver circuits specify a minimal distance between the spade leads and resistors. Internalizing the resistors reduces the distance to an absolute minimum, permitting the MO-10R's uniquely high 10 MHz counting speed.
Note the unusual 20-pin envelope. All other beam switching tubes (with the exception of various early sleeve anode tubes and the BD-309, a shielded MO-10R variant) feature one of several similar 25- and 26-pin configurations.
The MO-10R is packaged in a standard 6700-style box, and includes a pinout diagram and magnet warnings.
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