Click for homepage
← ETM-1810/M
HF radio modem with FEC - this page is a stub

ETM-1820/M is a high-end HF radio modem with error-correcting features like Forward Error Correction (FEC) and echo-cancelling, developed around 1985 by Telefunken 1 in Ulm (Germany). The device was mainly intended for use by the German Armed Forces and by its NATO allies.

The device supports multiple waveforms and allows additional modes to be added later by updating the firmware or by soft-loading them.

The ETM-180/M was commonly used in the fully adaptive (modified) STANAG 4285 mode with QPSK in the upper sideband and suppressed carrier (J2D). Data transmissions generally took place in 3.2 sec frames at a speed of 2400 baud. When in use, the LCD display at the front panel continuously shows the quality of the signal. The device can also be remote controlled, e.g. by the ARCOTEL ACT-1810 transmission processor.

The device was also used in FARCOS and MAHRS systems, and as part of the HF-7000 special forces radio system. During the Cold War it was also used as part of the base station of the pan-European HARPOON stay-behing radio system. It is fully compatible with the remote controlled ETM-1810/M which has a limited control panel and misses the liquid crystal display (LCD). The ETM-1820 was also used as the basis for the TST-4045 HF Modem made by Timmann (TST).

  1. Due to name changes, the ETM-1810 was also sold under the names Telefunken System Technik (TST), DASA, EADS, Racoms, EADS Racoms, and Telefunken Racoms.

  • Serial single-tone  waveforms
  • High data rates up to 19,200 bps
  • Decision feedback equalizer
  • Efficient forward error correction (FEC)
  • Short acquisition at start of transmission
  • Very robust  transmission modes
  • Suitable for STANAG 5066 systems
  • Suitable for duplex, half-duplex or simplex HF radio connections
  • Suitable for short signal transmission (e.g. DF commanding)
  • Suitable for continuous or long-term transmissions (broadcast, fax, text, etc.)
  • Suitable for transmission of digitized, coded voice
  • Built-in Test-Equipment (BITE)
  • Data interface operable in synchronous and asynchronous mode
  • Modem setting via front panel
  • Remote control via serial-line or Ethernet
  • Mains or battery power supply (option)
  • Stationary or mobile applications
  • 19" 1U rackmount module
Transmission modes
  • MIL-STD-188-110A/B
  • MIL-STD-188-110B Appendix F (ISB)
  • STANAG 4539 Annex B, inclusive Autobaud
  • STANAG 4415 75 bps (NATO robust waveform)
  • STANAG 4481 FSK
  • STANAG 4285, including Annex E
  • STANAG 4529 (Narrow-Band)
Single-tone waveforms
  • STANAG 4538
  • STANAG 4539
  • STANAG 4285
  • STANAG 4529
  • MIL-STD-188-110B including Appendex F (ISB)
  • Data
    EIA RS-232C, DIN 66020, CCITT V.24.V.28
  • Control
    EIA RS-232C, DIN 66020, CCITT V.24.V.28 (internal connector)
  • Speed
    75, 150, 300, 600, 1200, 2400, 4800, 9600, 19200 baud asynchonous
Compatible equipment
The following equipment is known to be compatible with ECHOTEL:

  1. Telefunken Racoms, ETM 1820M
    Retrieved February 2018.
Further information
Any links shown in red are currently unavailable. If you like the information on this website, why not make a donation?
Crypto Museum. Created: Tuesday 20 March 2018. Last changed: Monday, 26 March 2018 - 15:04 CET.
Click for homepage