Control, Data, and Telephone Line
Low-Voltage TEMPEST Filters

TSS USA Manufacturing provides low and medium voltage TEMPEST filters to protect sensitive data and telecom applications from unplanned EMI and EMP events.

For facility engineers overseeing sensitive data and telecom applications, security is always important. But in heavily regulated and sensitive applications—military and national security, healthcare, finance, energy, transportation, communications, and industrial—security needs are far beyond important. They are critical.

Information gained by the wrong people could mean a threat to a company’s competitive position and profits, the loss of personal data, or even a threat to the safety and interests of a nation.

The same factors that can allow the incursion of interference, such as antennas, wiring, enclosures, and even power and data cables, can also permit their transmission. While data can be radiated by equipment, the biggest concern is conducted emissions. Information can ride for long distances on existing wiring, like power wiring.

TEMPEST filters can help eliminate unplanned emanation of electromagnetic radiation (EMR) and, with it, sensitive, confidential, and classified information that might allow access to unauthorized persons. TEMPEST, which stands for Transient Electromagnetic Pulse Emanation Standard, is a U.S. National Security Agency and NATO specification and certification to prevent eavesdropping and signal interception because of unplanned outgoing EMR.

A TSS USA Manufacturing TEMPEST line filter provides a 100 dB insertion loss across a broad spectrum of signals. Because decibels are a logarithmic unit, that’s 0.001% of the original signal, making interceptions next to impossible.


This range of 3- and 4-line filters is suitable for a range of control and telecom applications including:

  • Filtering control and low current power lines on shielded rooms and general installations.
  • Carrying digital data circuits and analogue telephone circuits into shielded rooms and communications cabins.
  • Acting as in-line filters for information security applications.

Compliance Standards

All control, data, and telephone line filters are rigorously tested and meet or exceed the relevant performance and/or safety criteria defined within these standards:

  • MIL-F-15733
  • MIL-STD-220C


  • Voltage rating: 120/230 VAC @ 60 Hz
  • Capacitance: in compliance with MIL-STD-202, Method 305 @ 1 kHz
  • Visual/mechanical construction: in compliance with MIL-F-15733, paragraph 4.6.1
  • Insulation resistance: 1500 MΩ (as per MIL-STD-202, Method 302)
  • Dielectric withstanding voltages: 1000 VDC line-to-line and line-to-chassis (as per MIL-STD-202, Method 301)
  • Insertion loss: in compliance with MIL-STD-220
  • Voltage drop: less than 1% of the rated voltage
  • Terminal strength: in compliance with MIL-STD-202, Method 211
  • Leakage current: 5mA maximum @ 120 VAC, 60 Hz
  • Voltage discharge: less than 30 VDC after removal of power
  • Operating temperature range: -55º C to +70º C

TSS USA Manufacturing TEMPEST filters are manufactured using predominately U.S.-sourced materials and meet the FAR 52.225-1 Made in America.

Our experts can guide you through your filter section and our engineering services are available at no extra charge.