Canford LS300 Series Instruction manual

technical data
CANFORD AUDIO PLC
CROWTHER ROAD, WASHINGTON
TYNE & WEAR, NE38 OBW. UK
admin 0191 418 1000
sales 0191 418 1122
fax [phone]
02-123(Issue 3)10/94
LS300 SERIES TALKBACK LOUDSPEAKER STATIONS
27-311 TECPRO LS311T Loudspeaker station, single circuit, metal case
27-312 TECPRO LS312T Loudspeaker station, multi circuit, metal case
27-321 TECPRO LS311F Loudspeaker station, single circuit, flushmount
27-322 TECPRO LS312F Loudspeaker station, multi circuit, flushmount
27-331 TECPRO LS331 Loudspeaker station, single circuit, rackmount
27-332 TECPRO LS332 Loudspeaker station, multi circuit, rackmount
27-341 TECPRO LS311TW Loudspeaker station, single circuit, wood case
27-342 TECPRO LS312TW Loudspeaker station, multi circuit, wood case
1CONNECTING THE STATION TO THE
SYSTEM
"Loop-Through" Wiring - Two parallel wired
connectors are provided on most stations to allow
wiring to be looped through and on to the next
station if required. The female connector is used as
the input and the male connector as the output by
convention.
LS311/TandLS331Singlecircuitstations-Use2-
core screened cable and connect as shown in
diagram (1) using XLR-3 type connectors.
LS311/F Flush mount single circuit stations - For
ease of installations, these are provided with a plug
which connects to incoming wiring using screw
terminals. Wire as shown in diagram (2) using 2-
core screened cable.
LS312/F Flush mount multi-circuit stations - For
ease of installation, these are provided with a 12 pin
plugwhichconnectstoincomingwiringusingscrew
terminals. Wire as shown in diagram (3) using
multi-conductorindividuallyscreenedcableforbest
performance. Overall screened cable will work but
will suffer crosstalk between circuits when used
over larger distances.
LS312/Tand LS332Multi-circuit stations - These
are provided with 6 pin Neutrik type XLR
connectors. Up to 4 circuits can be connected.
Connect according to diagram (4) using multi-
conductor individually screened cable.
Wiring instructions for all types should be
attached to the station.
2 BASIC OPERATION
Operation varies slightly when the station is used
with built-in loudspeaker alone, headset, or plug-in
microphone.
Loudspeaker only operation
The function switch on the right of the unit is the
main operation control.
OFF - The loudspeaker is silent. The signal lamp
will still operate, to attract your attention if
required.
If a headset or accessory microphone is in use, they
are unaffected by this switch position.
LISTEN-The loudspeaker will be on, the volume
control can be used to set a suitable level.
TALK - Allows you to speak to the circuit. The
switch has a momentary action andwillspringback
to LISTEN when released. It switches off the
loudspeaker and uses it as a microphone. Tone
correction is applied to produce clear speech. You
may then speak normally so long as the switch is
pressed,andyouwillnothearthecircuitthroughthe
loudspeaker.
HEADSET OPERATION
ATecpro compatible headset wired as in diagram
(5) can be plugged into the station's front panel
socket. Internal circuitry automatically mutes the
loudspeaker when the headset is plugged in.
MIC ON/OFF - Located on the left of the Signal
Light switch, this is a latching key which activates
the headset mic to speak to the system. The
microphone amplifier gain is factory set to suit
most dynamic headset microphones. It contains a
limiter/compressor which prevents system
overload.
The volume controlnowcontrolstheheadsetlisten
level.
TALK -Still can be used to speak to the system if
requiredthroughtheloudspeaker. Inheadsetusethe
'Off/Listen/Talk'switchisnormallynotusedandhas
no affect on headset operation.
3 USE WITH ACCESSORY MICROPHONES
LSM-1 PLUG-IN GOOSENECK MICROPHONE
An LSM-1orequivalentmicrophonecanbeplugged
into the front panel socket instead of a headset.
This can convert the LS300 series station to hands-
free 2-way operation. In this case the Mic 'On/Off'
switch activates the plug-in mic. The loudspeaker
will simultaneously receive the circuit audio and is
controlled by the 'Off/Listen/Talk' switch and
volume control.

technical data
CANFORD AUDIO PLC
CROWTHER ROAD, WASHINGTON
TYNE & WEAR, NE38 OBW. UK
admin 0191 418 1000
sales 0191 418 1122
fax [phone]
02-123(Issue 3)10/94
Hands-free 2-way speech using the plug-in
microphone must be used with care to prevent
systemfeedback. Becauseofthecloseproximityof
the loudspeaker to the microphone the sidetone
requires very careful adjustment. This is because a
portionofthesoundre-enteringthemicrophonecan
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,
preventingthelocalmic'howlingaround'throughthe
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 TALKswitch) 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.
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 gentlytapping 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).

technical data
CANFORD AUDIO PLC
CROWTHER ROAD, WASHINGTON
TYNE & WEAR, NE38 OBW. UK
admin 0191 418 1000
sales 0191 418 1122
fax [phone]
02-123(Issue 3)10/94
Mode (4)
Set from TALK to LISTEN and set to preset level -
prevents local talk in addition to mode (1).
The mode is set with links on the printed circuit,
locations are marked on the rear PCB. The modes
are selected as follows.
Mode Link 1 Link 2 Link 3
0Cut Cut Cut
1Make Cut Cut
2Make Make Cut
3Make Make Make
4Make Cut Make
7 CLEARCOM COMPATIBILITY
Tecpro stations are completely compatible with
Clearcom stations. Any Tecpro stations added to
Clearcom will function as their Clearcom
equivalents. However, Clearcom stations have a
lower bridging impedance and will degrade a
Tecpro system slightly due to a reduction in side-
tone stability incurred when a Clearcom outstation
is used in a Tecpro communications system.
Additionally, override tone may be reduced in
effectiveness by Clearcom stations.

technical data
CANFORD AUDIO PLC
CROWTHER ROAD, WASHINGTON
TYNE & WEAR, NE38 OBW. UK
admin 0191 418 1000
sales 0191 418 1122
fax [phone]
02-123(Issue 3)10/94