Burroughs BX-4000  
Written by Accutron on 2006-10-11  

The BX-4000 is a low voltage variant of the BX-2000, and the only Beam-X tube with known specifications to be rated at 1 MHz instead of 2 MHz. However, the BX-4000 is capable of staying in the megahertz region at a much lower spade voltage and much higher spade resistance than the BX-1000. A BX-1000 powered to BX-4000 specifications would be riding the lower boundary curve of its stable operating region, and would not be capable of 1 MHz operation.

The BX-4000 was quickly superseded by the BX-4001, identical in electrical characteristics but capable of full 2 MHz operation. There are only a handful of BX-4000 / BX-4001 devices known to still exist.


Burroughs BX-4000, a low voltage Beam-X variant in a standard shielded envelope.


The BX-4000 was shipped in a medium-sized carton with end flaps and a solid foam insert.

This article is part of the [Beam Switching Tubes] exhibit.

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