Crown Broadcast FME 350W to 2000W User Manual– 05/2013
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CLIP
(CONF.DEV.CLIP) – read/write
With this parameter, set the MPX hard clipper to prevent any possibility of overmodulation on the modulator
itself. This process is carried out digitally right before the RF generation and is therefore enabled on all the
inputs. If the deviation is greater than the configured value (in kHz), the MPX hard clipper is automatically
enabled. Unlike FM limiters/clippers used in audio processing, this clipper cannot be used continuously for it
generates a noticeable audio distortion. It is therefore best to set it at 0, or at the maximum authorized
deviation, plus a few kHz to ensure additional security with the audio processor.
From 0 to 200 kHz
The FM Limiter option includes 3 processing stages:
AGC: The Automatic Gain Control purpose is to compensate level variations applied to the
selected audio input. The algorithm is wide-band for maximum audio fidelity and gated to avoid
noise and unwanted level corrections.
FM LIMITER: The FM Limiter prevents from over-modulation by limiting the audio peaks.
MPX POWER LIMITER: The MPX Power Limiter is based on to the ITU-R 412 standard applied
on some FM markets.
CLIP STATE
(CONF.STATE.CLIP) – read/write
This parameter enables or disables the clipper. Default: off.
Off/On
CLIP
(CONF.DEV.CLIP) – read/write
Set in kHz, this parameter represents the maximum FM deviation and is used as a reference by the FM
Limiter algorithm. Default value: 75 kHz.
From 0 to 150 kHz
AGC STATE
(CONF.AGC.STATE) – read/write
This parameter enables or disables the Automatic Gain Control processing stage. Default: off.
Off/On
AGC DRIVE
(CONF.AGC.DRIVE) – read/write
With this parameter, load more or less the AGC input. At 0 dB gain reduction will be applied when the
transmitter is fed by an audio level higher than the input level setting. Increasing the drive will add gain
reductions, while low audio levels will be increased (more processed). Default value: +4 dB.
From 0 to 12 dBu
AGC ATTACK
(CONF.AGC.ATT) – read/write
With this parameter, tune in dB/s the AGC reactivity speed to a volume increase. A high setting is
recommended to protect the FM limiter stage against high audio levels and possible audio distortions.
Default value: 8641dB/s
From 0.1 to 10 000 dB/s
