Pro Intercom LS3 Operating Instructions Manual

LS3

Talkback

Loud speaker Sta tions

Op er ating In struc tions

Mod els: LS3 (Flush mount for a six gang elec tri cal box); LS3T (In its own heavy metal desk
top or wall mount en clo sure); LS3R Rack-mount [2U]. Add an "M" to any of these mod els
for the multi-cir cuit ver sion: LS3M, LS3MT, LS3MR.

Three Op er at ing Modes

You have pur chased the most so phis ti cated Talkback loud speaker sta tion avail able. It can be used,
with out mod i fi ca tion, in any one of three modes. In all modes the sig nal light but ton is op er a tive, and
the vol ume con trol ad justs the level of ei ther the loud speaker or the head phone/hand set earspeaker.
The LS3 de tects the mode of op er a tion which you have cho sen, and au to mat i cally ad justs it self.

1. Press-to-Talk Mode:

As the term im plies, the op er a tor merely presses the Off/Lis ten/Talk switch to its Talk po si tion to com ­mu ni cate with other sta tions on the sys tem. The loud speaker acts as a mi cro phone in this po si tion.
The spring-loaded switch will re turn to the Lis ten po si tion when re leased. The Off/Lis ten/Talk switch
will mute the loud speaker when placed in the Off po si tion. The sig nal lamp will still op er ate with this
switch turned Off.

2. Head set/Hand set Mode:

Plug ging a head set or tele phone hand set into the front panel 4-pin XLR will cause the LS3 to func tion
ex actly as a ‘belt pack’ or head set sta tion. The LS3 de tects the pres ence of the head set or hand set,
and au to mat i cally dis con nects the loud speaker. The Mi cro phone On/Off switch is used to mute the
mi cro phone in the head set or hand set. The Off/Lis ten/Talk switch should be left in the Lis ten po si tion
in this mode.

3. Full Du plex, Hands-free Mode:

When a "Gn x" gooseneck mi cro phone is plugged into the front panel 4-pin XLR, the LS3 de tects this
and shifts to its full du plex, hands-free mode. The gooseneck mi cro phone and the built-in loud ­speaker op er ate si mul ta neously, with none of the ‘clip ping off’ of ini tial con so nants, as hap pens in a
VOX op er ated cir cuit. The op er a tor may speak and lis ten at the same time, with out any switch ing.
The very high ‘sidetone re jec tion’ per for mance of Pro In ter com sys tems per mits this use with out
feed back, and at sur pris ingly high lev els. A close-talk ing, noise can cel ing gooseneck mic is rec -
om mended for best per for mance in this mode. The re cessed sidetone con trol (ac ces si ble through
the front panel) must be op ti mized. See the sec tion be low on Sidetone Ad just ment. Only one LS3
may be used in this mode within any one acous tic en vi ron ment. At tempt ing to use more than one
with out acous tic iso la tion may re sult in se ri ous feed back prob lems. In a noisy en vi ron ment, the Mi ­cro phone On/Off switch may be used to mute the out put of the mi cro phone to other sta tions. A
hand-held push-to-talk mi cro phone (HH5) may be sub sti tuted for the gooseneck mi cro phone to ob ­tain the same re sults.

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Phone: [phone] Or ders and Tech sup port: [phone] Fax: [phone]

Printed in U.S.A.

sup [e-mail] Skype: intercom4pros

Pro In ter com LLC

PO Box 7035 Al gon quin Il li nois 60102-7035

Rev.2_01.13

Sig nal Lamp Op er a tion

The sig nal lamp but ton, when pressed, lights it self and all other sig nal lamps in sta tions on the

same com mu ni ca tions cir cuit.

‘Sidetone’

Sidetone is sim ply the sound of your own voice, heard in your own ear, when re fer ring to a head set or
tele phone hand set. You ex pe ri ence it ev ery day when you use a tele phone. When the LS3 is used in
its full du plex mode, we are ex pand ing that def i ni tion to in clude the sound of your own voice, picked
up by the gooseneck mi cro phone, and re pro duced by the LS3’s loud speaker.

Un like ‘belt packs’ and head set sta tions, the sidetone con trol in an LS3 is au to matic when a head set
or hand set is con nected to the unit. The re cessed sidetone con trol (ac ces si ble through the front
panel) is only ac tive when the sta tion is be ing used in its full du plex hands-free mode, with a Gn'x'
gooseneck mi cro phone plugged in. We strongly rec om mend a close-talk ing, noise-can cel ing
gooseneck mi cro phone in this mode. Sidetone ad just ment is crit i cal to best per for mance. It is the
re duc tion of sidetone to near zero which al lows the mi cro phone and the loud speaker to be ac tive si ­mul ta neously with out pro duc ing feed back. Be fore plug ging in the gooseneck mi cro phone, ad just the
vol ume to a com fort able level when lis ten ing to other sta tions. Next turn Off or dis con nect all the other
sta tions in the sys tem. Do not ad just the vol ume. Plug in the gooseneck mi cro phone and switch the
Mic. switch to On. Ad just the sidetone con trol with a small screw driver while tap ping lightly on the mi ­cro phone. The qui et est po si tion will be a ‘null point’ some where near the cen ter of the con trol’s ro ta ­tion (near 12 o’clock).

Over ride Con trol Fea ture

LS3’s are equipped with a re ceive cir cuit which re sponds to a con trol tone gen er ated else where in the
sys tem by an OG904 Over ride Gen er a tor mod ule. An OG904 can be fit ted into any Pro In ter com
sta tion which can be used with a head set, hand set, or mi cro phone. This in cludes ‘belt packs’, head ­set sta tions, mas ter sta tions, or other LS3’s. The over ride tone may be trig gered by a sep a rate switch
added to any of these de vices, or by their mi cro phone On/Off switch.

When the LS3 de tects the con trol tone, it will switch to a pre de ter mined mode, re gard less of the po si ­tion of any of its front panel con trols. The vol ume may be raised or low ered. The sta tus may be
shunted from Off to Lis ten. The Talk func tion may be dis abled.

Typ i cal among ap pli ca tions for this fea ture are: re stor ing vol ume in a dress ing room where the front
panel con trol has been turned down; mut ing a sta tion when com mu ni ca tions should not be heard at
that lo ca tion, and; mut ing a sec ond LS3 in a nearby lo ca tion while the first is send ing.

There are five modes of con trol, de ter mined by the po si tion of the re cessed Over ride level con trol ac ­ces si ble through the front panel, and add ing or re mov ing links on the rear PC board.

Mode 0: No over ride func tion
Mode 1: Switch to pre set over ride vol ume level
Mode 2: As mode 1, plus shunts Off/Lis ten/Talk from Off to Lis ten
Mode 3: As mode 1, plus shunts Off/Lis ten/Talk from any po si tion to Lis ten.
Mode 4: As mode 1, plus shunts Off/Lis ten/Talk from Talk to Lis ten

As sup plied from the fac tory, your LS3 is set for Mode 3.

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The mode is es tab lished by links on the rear PC board.

Set the mode as fol lows:

MODE Link 1 Link 2 Link 3

0 Cut Cut Cut

1 Make Cut Cut

2 Make Make Cut

3 Make Make Make

4 Make Cut Make

Com pat i bil ity with Clear-Com

®

Pro In ter com sta tions are com pat i ble with Clear-Com® and other pop u lar party-line sys tems op er at -

ing on a 200W un bal anced line. A Pro In ter com sta tion added to a Clear-Com® sys tem will op er ate as
its Clear-Com® equiv a lent. Due to dif fer ences in bridg ing im ped ances, you may not be able to
achieve suf fi cient sidetone re jec tion in an LS3 (con nected to a Clear-Com® sys tem) to use the LS3 in
its full du plex hands-free mode. Stock Clear-Com® sta tions can not gen er ate the Over ride tone.

Con nec tions

Sin gle-cir cuit Mod els

Head set, Hand set & Gooseneck Mics

¬ ¬ Multi-cir cuit Mod els ® ®

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About the ro tary se lec tor switch on ‘M’ ver sions

This ro tary switch is spe cially cho sen be cause it con nects to the next se lec tion be fore it dis con nects from the first

(refered to as 'short ing'). This elim i nates an noy ing ‘clicks and pops’ as the switch is ro tated. It is ca pa ble of switch ing up

to 9 cir cuits but, in our LS3MT (the ta ble-top or sur face mount ver sion) and the LS3MR (the rack mount ver sion), it can

only switch four cir cuits be cause that is all the 6-pin XLR con nec tor can han dle. By far the ma jor ity of these sta tions are

used in 2-cir cuit ap pli ca tions and the switch is fac tory set so that only 2 po si tions are avail able. If you want to use more

than two po si tions, and we did n’t set this up for you when you ac quired the sta tion, please see the set of in struc tions be -

low for al ter ing the num ber of po si tions avail able.

Re move the knob from the se lec tor switch and the PC board from its mounts. Loosen the nut on the
shaft and lift the lock ing ring gently, not ing the po si tion on the switch into which the tab was in serted.

(Note: on some mod els the switch presses so firmly against the panel when the PC board is mounted,
that the nut is not nec es sary.) Ro tate the lock ing ring to the third or fourth slot in the body of the switch

and press it firmly into place. Re-tighten the nut (if used) firmly by hand. Re as sem ble the PC board
onto its mounts, check ing that the front panel switches all move freely be fore tight en ing the mount ing
screws. Re-in stall the ro tary switch knob.

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