Marconi-Ekco Instruments Ltd.
Electra House, Victoria Embankment, London WC2, England (1936)

Marconi Instruments Ltd.
Longacres, St. Albans, Hertfordshire, England

Marconi Instruments (formerly Marconi-Ekco, MEI), also known as MI, was a manufacturer of electrical measuring and testing instruments, including automatic testing equipment. They made signal generators, oscilloscopes, voltmeters, spectrum analysers and other products.

For a short time in the 1930s, MEI also fabricated valves/tubes under the label "Marconi-Ekco".

MI had many dependencies around the world that catered the local markets mostly as distriubutors and service organizations. The USA branch, Marconi Instruments, Inc. (MII), released a series of models specifically designed for the USA - details about place of design and manufacture are not known at this time).

Please see this forum article for a list of addresses and names of local companies.

In 1936, Marconi's Wireless Telegraph Company and E.K. Cole Ltd. (EKCO) form a jointly-operated company to be called Marconi-Ekco Instruments Ltd. with a nominal capital of £5,000. The manufacture of electrical measuring and testing instruments of EKCO and Marconi is taken over by the new company.

The name of the company is changed to Marconi Instruments Ltd. in 1941/1942 after E.K. Cole sold the whole of its share interests.

Due to the acquisition of Marconi's Wirless Telegraph Co. by English Electric Company Ltd. (UK), Marconi Instruments becomes part of the latter in 1946.

In 1968, GEC (UK) buys English Electric. Marconi Instruments is sold to IFR Systems Inc. (USA) in 1998.

Aeroflex Inc. (USA) acquires IFR Systems Inc. in 2002 and is itself taken over by Cobham plc (UK) in 2014.