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Data sheets for receivers 1037A, 1906, 1907, 2074, 2801

Nems-Clarke has a long history. It started in 1951 when Clarke Instruments merged with National Electric Machine Shops (NEMS)

In 1951, Clarke Instruments was a small ten person design firm run by Allan Clarke. It rented space from the on the King Street entrance of the NEMS building at 919 Jessup Blair Drive in Silver Spring MD.

NEMS has a long history. The name was chosen in 1937 when the National Electric Supply Company incorporated. NESC was founded in February 1899 and manufactured radio parts from the very beginning of radio. Company archives contained photographs of transmitters produced for the Navy in 1909.

By 1951, NEMS was purely a production house. They took schematics and mechanical designs from other firms and built equipment. For example, some of RCA's early TV alignment generators were built by NEMS and shipped off to RCA for marketing. They owned the building at 919 Jessup Blair Drive. It housed machine shops, sheet metal fabrication, assembly and test facilities.

As Clarke Instruments was primarily a design firm and NEMS was an established production house, the merger quickly bore fruit. The name was offically changed to Nems-Clarke in January of 1955.

Allan Clarke hired future CEI founder Ralph Grimm after Grimm dropped out of Capitol Radio Engineering Institutes (CREI). Grimm was a brilliant engineer who developed new and highly respected products for the firm. Grimm would become one of Clarke's favorite engineers. To supplement his day job at Nems-Clarke, Grimm started teaching night classes at CREI, even though he never graduated.

Grimm designed or "had a major hand" in the new Nems-Clarke line of telemetry and special purpose receivers. These products were quickly snapped up by the military for ballastic missle telemetry. The 2501 receiver and associated preamplifiers was used in the TRANSIT satellite program. For the DISCOVERER space program, they developed the DCA series of diversity combiners. The 1455 receiver was developed for the CENTAUR booster rocket program.

Grimm also designed the Megalume electronic strobe lights and the 107-A and 120-D field strength meters that proved very popular in the broadcast industry.

In September 1957, Nems-Clarke was purchased by Vitro Corporation of America and the name was changed to Vitro Electronics. Vitro Corporation encompassed a variety of industries. Vitro subsidiaries designed, constructed and operated nuclear, chemical, metallurgy and defense facilities. They also produced uranium concentrate, thorium, rare earths and rare metals.

In the early Vitro Electronics years, the engineers at the Jessup Blair building developed the 1037A telemetry receiver. The 1037 was used for reception of all signals in the Mercury and Gemini manned space flight programs. These were hectic and exciting times. Engineers often worked erratic and late hours. The goal was to beat the Russians and adrenalin flowed freely. Many radios were modified at the last minute to gain "a dB here or a dB there." Some were shipped not matching the catalog and with circuits looking more like prototypes, but the end users were happy.

Vitro Electronics put two 1037s and a diversity combiner in one box and called it the 2074 (twice the 1037). This radio was developed and successfully used in the Apollo manned space program. Because a space craft rotates relative to the earth, the phase of the signal is constantly changing. The 2074 had two full 1037 receivers right to the end of the IF stages. The diversity combiner was inserted before the detector. This yielded a 6 dB improvement over using two separate receivers and a post detection or audio satge combiner.

The 2074 was used for much of the Apollo program. "One small step..." probably came through a Scientific Atlanta antenna and a Vitro Electronics 2074 receiver.

The Nems-Clarke engineers traditionally were driven to continually push the performance envelope. Every innovation that squeaked out a little more signal or produced a little less noise was vital to communicate reliably across the vast distances of space and through the noisy and absorptive ionosphere.

This design ethic didn't sit well with the new Vitro management, which was largely from New York. Prior to the purchase by Vitro, Nems-Clarke was a privately held corporation. Vitro's New York managers didn't like the way Nems-Clarke was run. Their New York offices began to change the management structure. In the process they drove off many long time managers and replaced them with their own.

The new Vitro managers wanted fully developed and frozen designs without expensive customization. Things they could market. As one former employee put it, "they were trying to tell us dumb engineers how to run our business, which we had been quite happily doing, and they didn't even know what an electron was."

One of the first groups to leave formed Defense Electronics, which was incorporated in October, 1959. The telemetry business was booming and a few engineers recognized and seized the opportunity. They quickly "got in tight" with NASA. Early in the Apollo program, DEI landed the contract for the ship and plane based telemetry receivers. Vitro held onto the ground based contract. Eventually DEI took over Vitro Electronics telemetry product line. The 1037 was renamed the 1037-G and the 2074A was offered. Both appear externally unchanged except for the DEI name plate. These two receivers were displaced somewhat by the new TR-711. However, DEI's TMR series clearly owes a debt to the older Vitro Electronics.

Nems-Clarke made only a handful of surveillance receivers, the bulky and noisy 1301, 1302 & 1306 were produced in significant quantities. They used the 416B tube in the RF stage which required noisy forced air cooling - unusual for a receiver. The 416B was a fine amplifier but not that quiet. Adding to the limitations, these units were 5 rack units high.

The 1906, 1907 and 2801 are more desirable units. They were vastly superior in performance, size and quietness, both electrical and mechanical. All three were purchased and modified for airborne use by LTV (see the G175 tech sheet for pictures and info on these modified units). The 1906 and 1907 were listed in the 1961 Vitro Electronics catalog as "compact telemetry receivers". All of the 1906 and 1907 radios I have seen, including those pictured in the catalog, bear the tag "special purpose receiver". Only the 2801 was advertised as "an extended coverage surveillance receiver". To my knowledge, surveillance receivers were a side effort of the Nems-Clarke line of Vitro Electronics.

Nems-Clarke is significant in WJ history because several employees led by Ralph Grimm, left Vitro/ Nems-Clarke to form the new Communications Electronics Incorporated (CEI). Ralph Grimm was the president of CEI until he was allegedly ushered out after WJ purchased CEI. Peter Pao was an RF design engineer for Nems, CEI and was one of the founders of Astro Communications Labs.

If you have any indormation, particularly early catalogs from Clarke Instruments, NECS, NEMS, Nems-Clarke, Vitro, Defense Electronics, Inc or Astro Communications Labs, please contact me. I am always eager to fill in gaps in this fascinating history.