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Hands-free 2-way speech using the plug-in
microphone must be used with care to prevent
system feedback. Because of the close proximity of
the loudspeaker to the microphone the sidetone
requires very careful adjustment. This is because a
portion of the sound re-entering the microphone can
be re-amplified and leads to 'howl round'. Follow
the instructions in the Sidetone Adjustment in
section (5) below.
Important Note:
Sidetone cancellation and
stability are excellent at any single LS300 station,
preventing the local mic 'howling around' through the
local loudspeaker from local speech. In systems
with several LS300 stations using the LSM-1 for
hands free speech acoustic feedback can take place
around the system.
This is dependant on the
loudspeaker levels and room acoustic properties.
Tecpro recommends use of only one LS300
station in this mode in any one circuit. Operation
of more than one station in this mode should be
undertaken with care. Please consult ourselves or
your dealer for advise.
HH5 Fist Mic
Because of the omni-directional nature of the
internal loudspeaker/microphone, its use (by
pressing the TALK switch) in a noisy environment
is unsuitable. This is due to the amount of
background noise that can be picked up.
The HH5 fist microphone is plugged into the
headset socket. Loudspeaker operation is not
affected. Mic On/Off should be switched 'On'.
Holding the HH5 close to the mouth and speak
while pressing the push switch on its side. Clear
speech without such background sound will be
heard on the rest of the system.
4 SIGNAL LIGHT OPERATION
The SIGNAL pushbutton flashes a light in all
outstations connected to your circuit. It is used to
attract the attention of a user that has a headset
removed or station switched off.
This light signal capability can be used for other
special purposes such as activating transmit to a
radio system connected via an AD913 Radio
Interface Adapter.
5 SIDETONE ADJUSTMENT
Headset Use
The level of your voice in your headset, is called
'sidetone'. When using a headset this level is fixed
and the sidetone control is inactive. The fixed
level suits most standard professional headsets for
normal commercial uses.
02-123(Issue 3)10/94
CANFORD AUDIO PLC
CROWTHER ROAD, WASHINGTON
TYNE & WEAR, NE38 OBW. UK
admin 0191 418 1000
sales 0191 418 1122
fax 0191 418 1001
technical data
Loudspeaker Use
When the station is used in loudspeaker only
mode operation is push-to-talk and sidetone has
no relevance.
Use with Accessory Microphone
The sidetone control is factory preset to give
minimum output of the microphone through the
station's own loudspeaker. Sidetone is affected
somewhat by external factors such as the wiring,
or connection of other stations. In the Tecpro
system this is minimised, but other compatible
systems are not so good.
For optional operation with an open microphone,
the sidetone must be adjusted to completely
cancel any sound from the microphone coming
through the loudspeaker. This is most easily done
by gently tapping the microphone whilst adjusting
the screwdriver preset until the sound disappears
from the loudspeaker. There will be a 'null'
position between the adjustment stops.
6 OVERRIDE CONTROL FUNCTION
LS300 series stations are equipped with a receive
circuit for an ultrasonic (25kHz) control tone
generated elsewhere on the system. The generator
(OG904) is usually fitted in the main or master
station so that when in 'talk' mode it can remotely
control these types of loudspeaker.
There are 4 modes of remote control.
Mode (0)
No override function
Mode (1)
Set to preset override volume level. This
adjustment is a screwdriver preset through the
front panel. This can be used to remotely restore
the volume when the main volume control is
turned down. Alternatively when turned fully
down this can be used to remotely turn the speaker
off.
Mode (2)
Set from OFF to LISTEN and set to preset level -
overrides local off switch in addition to mode (1).
Mode (3)
Set from OFF to TALK to LISTEN and set to
preset level - overrides local off switch and
prevents local talk ie master 'all call' or 'crash call'
in addition to mode (1).
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