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Monsanto 101B frequency counter (1969)

Monsanto101B-front.jpg
The Monsanto 101B is a 5-digit frequency counter-timer, up to about 100MHz. It is a sturdy instrument, made in USA.

The Monsanto 101B is a compact frequency counter-timer. It comes in a metal case with a tilt stand for bench use. Its display has Burroughs B-5750 nixies. It uses TTL for the digital circuitry.


  A look at the nixies and digital circuits,
	from above and behind.

A look at the nixies and digital circuits, from above and behind.

The 101B has a number of rotary switches to select the operating mode and gate time.

I bought this counter in spring 2004 through Internet. The person who sold it was a radio amateur who didn't use the counter any more. He didn't know whether it still functioned.

When I tried it, counter did work, but the range switches seemed to be a bit unreliable and the readings were not exact. I will have to invest some time to make this counter work again. This will be worth the trouble, I trust. It is a nice and compact counter, not too large like the other nixie frequency counters I have.


  A look from the bottom, showing the cable harnesses.

A look from the bottom, showing the cable harnesses.

At least, I have made a web page for it now...

Copyright © 2007 by Onno's E-page         published 2007-04-07