User's Manual

Figure 4-3 VOX Gate Setting Examples
Note: If the FS II beltpack users shouts or increases the microphone gain into the beltpack the echo
might return if the audio reflects are above the VOX gate level.
4.2.5.4 Auto null the partyline channel at the Base station
Partylines connected to the Base station can be auto nulled by first enabling partyline channel
by pressing the partyline button on the front of the Base station.
The auto nulling is then activated by pressing and holding the enable partyline button. The
Base station will go then into an auto null routine.
4.3 Wireless partyline
The FS II Base station provides five wireless partyline groups which allow up to twenty eight
members to be connected together in a conference call. The beltpack keys assigned to the
wireless partyline group are assigned as dual talk and listen and partylines connected to the
group are assigned as talk and listen.
When a beltpack or partyline talks to a wireless partyline group the talk signal from the
beltpack or partyline is subtracted from the listen signal to remove the sidetone resulting from
the user’s voice being looped back in the conference audio, leaving only the audio from other
members.
Party-line A
Nulling
circuit
-15dB
-30dB
The reflections from the party-line get delayed by the base station
encoding, decoding and the DECT stack which causes the echo.
V2.0 VOX gate
set to -26db
0dB
Party-line A
Nulling
circuit
-15dB
-30dB
V2.0 VOX gate
set to -26db
-20dB
Party-line A
Nulling
circuit
-5dB
-20dB
The reflection from the party-line can be removed by using the
new V2.0 VOX gate functionality therefore removing the echo.
But if the audio volume is increased either by shouting or increasing
the mic gain the party-line reflections will return, due to the VOX gate
set at a lower level.
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FreeSpeak II User Guide