Page 18
IBVR20 software 8.43.doc
Issue 1
The maximum input sensitivity without attenuation is 80mV (-20dBM). However the gain
may be reduced using a fine and coarse attenuator. The fine provides 15dB of
attenuation in approximately 1dB steps and the coarse provides 30 dB in 2dB steps.
Setting the attenuator correctly will prevent overloading the input stage and easier
adjustment of the system. If an input of 775mV (0dBm) is required than simply attenuate
the input by 20dB by setting the coarse to 09.
To set the input attenuator, move the cursor along until it flashes beneath the desired
attenuator window. Values between 0-9 may be entered directly using the numbered
keys. Note the cursor automatically steps to the next window. Or using the + or – keys will
increase or decrease the value between 00 (no attenuation) and 15 (maximum
attenuation)
Input dynamic compressor or limiter may be introduced to prevent overloading and
assists in maintaining a constant output volume if several operators use a microphone or
music with wide ranging levels..
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| IN 08|ATTENUATOR| COMPRESSOR |CHIME |
| |.00|....00|Off |Off |
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↑
To select either a limiter or compressor, move the cursor along until it flashes beneath the
above window.If no limiter or compressor is required, press 0 ,the display will indicateOff.
If a limiter action is required, press 1. The display will respond thus.
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| IN 08|ATTENUATOR| COMPRESSOR |CHIME |
| |.00|....00|Limiter 00|Fast|Off |
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If a compressor action is required, press 2. The display will respond thus.
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| IN 08|ATTENUATOR| COMPRESSOR |CHIME |
| |.00|....00|Compress 00|Fast|Off |
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↑
The threshold is adjusted by moving the cursor along until it flashes beneath the above
window.
Values between 0-9 may be entered directly using the numbered keys. Note the cursor
automatically steps to the next window. Or using the + or – keys will increase or decrease
the value between 00 (High threshold) and 15 (Low threshold).
------------------------------------------
| IN 08|ATTENUATOR| COMPRESSOR |CHIME |
| |.00|....00|Limiter 06|Fast|Off |
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↑
The release time may be either set Fast, ideal for speech or Slow, suitable for music by
moving the cursor beneath the above window.
Press 0 to select Fast release, or 1 to select Slow release.
