Spectrum Control Finds Its Next Owner in Greenbriar
Greenbriar adds a defense electronics platform as AEA exits the business it bought from J.F. Lehman in 2019
Spectrum Control makes the components that handle the radio signals used by radar, military radios, satellite links and missile guidance: filters that pass the wanted frequency and block the rest, attenuators that turn a signal down, amplifiers that boost it and dividers that split it.
October 1, 2026|John McNulty
Greenbriar Equity Group has agreed to acquire Spectrum Control, a maker of the electronic parts that filter, strengthen and shield the radio signals used in military radar, communications and satellites, from AEA Investors.
Radio frequency (RF) and microwave signals are the radio waves that radar, military radios, satellite links and missile guidance systems use to see, talk and navigate. Spectrum Control makes the components that handle those signals: filters that pass the wanted frequency and block the rest, attenuators that turn a signal down, amplifiers that boost it, and power dividers that split it among several antennas or receivers.The company also makes electromagnetic interference (EMI) filters, which keep electrical noise from one device from disrupting another, a constant hazard in an aircraft or ship packed with electronics. Other lines include power distribution systems, filtered connectors and secure cabinets built to the government’s TEMPEST standard, which stops classified data from leaking out as stray emissions an adversary could intercept.
Products are sold under the Spectrum Control name and the Weinschel, Inmet and PowerFilm brands. Weinschel and Inmet make RF signal-control and test components; PowerFilm makes miniature resistors and attenuators that mount on circuit boards. Customers are primarily aerospace and defense contractors, along with makers of space and commercial equipment.
A growing part of the business is modules that take an incoming analog radio signal, clean it up and convert it into digital data a computer can process. Built as compact packages or as plug-in cards for the rugged, standardized chassis used in military computers, they let a radar or electronic warfare system receive, sort and act on signals in one assembly.
Spectrum Control traces its roots to 1968, when engineers Thomas Venable, Glenn Warnhuis and John Lane started it in a converted hardware store in Erie, Pennsylvania, to make interference filters. Today, the company is led by CEO Rich Sorelle and employs about 1,100 people at 13 facilities in the US, Canada, Mexico and the UK. Spectrum Control is headquartered about 100 miles east of Cleveland in Fairview, Pennsylvania.
Rich Sorelle
“Over the past several years, our team has worked to build Spectrum Control into a leader in the RF component and subsystems space while remaining focused on solving our customers’ most demanding technical challenges and delivering the quality and reliability their missions require,” said Mr. Sorelle. “AEA has been a highly supportive partner throughout that journey. As we enter our next chapter, Greenbriar’s deep aerospace and defense experience, collaborative approach, and resources make them an ideal partner to help us accelerate innovation, expand our capabilities, and continue investing in our people and customers.”
The sale ends a seven-year hold for AEA, which acquired the business, then operating as API Technologies, from J.F. Lehman & Company in May 2019. Greenbriar will be the company’s third private equity owner since J.F. Lehman took API Technologies private in April 2016. The company changed its name to Spectrum Control in January 2023.
Vinay Kumar
“Over the course of our partnership, Rich and his team strengthened Spectrum Control’s position as a leading innovator in RF and microwave technology,” said Vinay Kumar, a partner at AEA. “Under their leadership, Spectrum has differentiated itself as a trusted solutions provider, well-positioned for sustained long-term growth as intelligence and autonomy become increasingly central to its customers’ mission-critical defense and aerospace systems. We’re proud of what we achieved together and we’re confident that Greenbriar will be an excellent partner for the company’s next chapter.”
The market for RF devices used in defense was worth about $1.5 billion in 2025 and is expected to reach about $2.8 billion by 2031, growth of roughly 11% a year, according to Yole Group. Demand is coming from the replacement of aging radar and communications equipment, the spread of drones and counter-drone systems, and a push to source critical defense electronics domestically. Recent conflicts have also shown that control of the radio spectrum, by jamming an enemy’s signals while protecting one’s own, can matter as much as the number of aircraft or ships.
Competitors to Spectrum Control include Mercury Systems, a Massachusetts-based maker of defense processing and RF subsystems founded in 1981 (NASDAQ: MRCY); MACOM, a Massachusetts-based maker of RF and microwave semiconductors founded in 1950 (NASDAQ: MTSI); and Teledyne Technologies, a California-based conglomerate founded in 1960 (NYSE: TDY).
Private equity owners of defense electronics businesses have found strategic buyers. Honeywell acquired CAES, a maker of RF electronics for the F-35, from Advent International for about $1.9 billion in September 2024. Amphenol bought defense cable assembly maker Trexon from Audax Private Equity for about $1 billion in November 2025.
Noah Blitzer
For Greenbriar, the attraction is Spectrum Control’s embedded position on defense programs and room to expand product development and manufacturing capacity. “Spectrum Control holds designed-in positions on some of the most important defense and aerospace platforms in production today, reflecting decades of customer trust and the company’s differentiated engineering capabilities,” said Noah Blitzer, a managing director at Greenbriar. “We look forward to partnering with Rich and the Spectrum team in this next phase of growth and are excited to support them as they continue to invest in new product development and expand their manufacturing capabilities to meet growing customer demand.”
Greenbriar invests in services and manufacturing businesses with specific interest in logistics, distribution, aviation, aerospace and defense, vehicle aftermarket, and advanced manufacturing. Greenbriar is currently investing from its seventh fund, Greenbriar Equity Fund VII LP, which closed above its $4.3 billion target in February 2026 with $5.4 billion of capital, up from $3.5 billion for its sixth fund in 2023. The firm was founded in 1999 and is headquartered in Greenwich, Connecticut.
Spectrum Control follows Greenbriar’s investments in managed transportation provider eShipping in January 2026 and freight forwarder AIT Worldwide Logistics in February. In December 2025, the firm formed Applied Aerospace & Defense, a maker of hardware for aircraft, satellites and missile defense systems that went public in June 2026.
AEA‘s middle market private equity group invests $200 million or more of equity in companies with enterprise values from $400 million to more than $2.5 billion and EBITDA of $25 million to $200 million. Sectors of interest include industrials, services and consumer, in North America and Europe. AEA also runs strategies for smaller companies and private debt. The firm was founded in 1968 by the Rockefeller, Mellon and Harriman family interests and S.G. Warburg & Co. and is headquartered in New York City.
Radio frequency (RF) and microwave signals are the radio waves that radar, military radios, satellite links and missile guidance systems use to see, talk and navigate. 
The company also makes electromagnetic interference (EMI) filters, which keep electrical noise from one device from disrupting another, a constant hazard in an aircraft or ship packed with electronics. Other lines include power distribution systems, filtered connectors and secure cabinets built to the government’s TEMPEST standard, which stops classified data from leaking out as stray emissions an adversary could intercept.
