ClearCom FreeSpeak II - Wireless Partyline

User Guide | FreeSpeak II™ Base station version
Page 41
level the user can cut the audio reflections (which cause the echo) from the
partyline when a wireless beltpack user speaks. This is achieved when the VOX
level is set above the audio level of the reflections, thus allowing a partyline user’s
voice to pass through the VOX gate in the Base station mixer but the VOX gate
will reject the audio reflections.
Note: If both the partyline user and the FS II user speak at the same time, the FS II
user may hear the echo as the audio reflections piggy back the partyline audio.
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.
4.3 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 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.