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UCR411a/UCR511a Audio Board Firmware Revision History


This model is not capable of firmware updates in the field so no files are available for download. Contact Lectrosonics if you need a firmware update.


UCR411a/UCR511a Audio Board v6.0 - 13 March 2013

  • Added compatibility mode 7.
  • Improved squelch system to ignore supersonic emissions from transmitters, especially "Mode 7" transmitters.
  • This version works on the same hardware as versions 3.0 and newer, but it must be used with RF board firmware v6.0 or newer.

UCR411a/UCR511a Audio Board v4.3 - 11 October 2012

Corrected modulation acceptance level in compatibility mode "EU M6". No other modes are affected.

UCR411a/UCR511a Audio Board v4.2 - 19 June 2012

Adjusted audio meter timing to more closely match transmitter audio metering.

UCR411a/UCR511a Audio Board v4.1 - 25 November 2009

  • Applied bug fixes and sonic refinements to mode 3.
  • Improved response to sharp acoustic transients.
  • Improved noise squelch and diversity systems for better performance under moderate to weak RF conditions.

UCR411a/UCR511a Audio Board v4.0 - 08 September 2005

  • Added compatibility mode 6.
  • Adjusted diversity switching algorithm for slightly quieter switching.
  • Dynamic noise filter now controlled by channel noise rather than signal strength to improve accuracy.
  • This version works on the same hardware as v3.2, but it must be used with radio board firmware v4.0 or newer.

UCR411a/UCR511a Audio Board v3.2 - 29 March 2005

Extended limiter overhead range in 200 Series compatibility mode.

UCR411a/UCR511a Audio Board v3.1 - 01 February 2005

Made frequency response very slightly flatter (using DSP to compensate for a 0.4 dB dip at 8 kHz).

UCR411a/UCR511a Audio Board v3.0 - 27 September 2004

  • Added IFB compatibility mode.
  • Added noise-based squelch.
  • Use only with radio board firmware version 3.0 or higher.

UCR411a/UCR511a Audio Board v2.0 - 12 May 2004

New firmware for Rev. E of the audio board.