UCR411a/UCR511a Audio Board Firmware Revision History 2.0 to 6.0 Series


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.