Telex user manual Wirsri?rcddsrrninssthe~opwrtingdist.nCc, Ths CM300URM300L with 25 ohm

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Wirsri?rcddsrrninssthe~opwrtingdist.nCc

(where theDC voltage drop is the limiting factor). Ths following eqlutioas apply for a wndnctor sizeof #22 AWG.a minimwnuser station voltage of 18.0 volts, d a minimum power supply voltage as stated below.

For Modds PSlO, PSM, PS31, P M , PS60, usa Vmin =

28.4VDC:

-D

(feet) P 322,181 1Ibt-( . .

1.

D h -

(mtgs)= 99,133 1Im (milliPmperes)

For Models PS8, PSl5 (Vmin = 24.0 MC):

. .

(feet) = 185,874 1Im (rmllumpcrcs1

D h c e - (map) = 56,654 1I&# (milli.mpsrss)

Exnmpk:

Ths CM300URM300L with 25 ohm

~ u s a

r u p t o 6 0. .

. With a PS8 supply

the maximum c p a h g ~ f o thisr anti011 is

185,874160 ''

= 3098 fkt (944 mstas). Asd

with a PS3l-y

the muimomopsnting dishlLce

 

= 5370 feet (1652 mtgs).

md a usa station with 25 ohm phollg (37mA) is 185,874EV = 5024 feet (1531-).

Anotha bmsfit of not "earth" grounding the circuit return is tht it prevents the h t m h t i o n of noise through 'earth" curw(sfrom other equipmeat. If the RTS Systmes circuit

gmund~tsthsc~l~nts,itisWrdythattheywillbc

hevd is interfering noise on thed 4 o n line.

Wirin~lC&&g(See Cable Wiring D

i in Section 7,

Application Momati011)

 

Two c h m d 'TW' applications, or single c l l m l d , thma wiro a p p l i ~ & ~IMY~ USE ather e~ ~ C ~ O ~ I I O cableD C (for canrmimcs) or hmhvkhl-paircable (Isss expensive tbrmmicqhomcnble). S I a n d a d w i r c r i z c f o r t h e ~

is#2zgougswiroforinkm=&h. F o r y t

iumWi01u arch chtlmd should have m i~~J~wdually shieldedtwistalpirof.tlasr#2zgurgewirc;wrchis

8723 for 2 ~ b m n dUUCI~ , mn for 3 cbmnels. POX plenum md I or 2CV' C wiring, use Bddea 88723 md 88777. Thsplaaum able hna a slighUy smaller d*metcr, isTefbninsul.tsd, d.boutthree. timgthepriceof 8723

18777.

System circuit g r d should not b k t l y c o n d to

W i r e u s i n g c a b l e W i ~ , S e c t i o n 7 , t o r e d u c e

 

 

intdemim UUCI help maintain a low crossc.1L f i p

'euth'or'chssis'zmund(dirseclvmesnsacamectionmbstmea*.

 

 

ohmmtawwld&).

~ g C T 8 1 . l i o n i s b ~ t o

 

 

its own chassis via a 0.1 microfaadcapacitor, stabli6biug

 

Liac levd is bchmwa 1OdBu md OdBu

a r P d i o f i . q l l c I I c y ( R F ) ~ t o r a d u e s n d i o ~The audio a&

i n ~ c e f m m n d i o t n n s m i ~ .

(bchvecn 0.24

.ad 0.77 volts rms).

Thwe levels are low

~ t o ~ t ~ i n t o & e q u i p m m t ( s u e b a s

 

 

To pre-vent a buildup

of voltage acm(g tbe system ca-

TV amsns) yet high amugh to minimirs extend

p l c i ~ , t h c p o w s r s u p p I y h s a b l s s d s r ~ t o c h . s s i s inmfemcetotheTWSpttm.

 

ground (22 kilohms). If the system hs no RTS Systems

The 200 ohm Liac i m p d a w is high enough to uUow

pow- supply, add a bleeder mistor at a cmotnl point in

the system.

 

mnnmmication om liae lengths of 1.6 kilometers (one

 

mile) d low mwgh to permit m d#lrule speech

 

 

The benefit of not 'earth' gnnmdiug the RTS System

bmdwidth with 3.2 kilomttefs of d

a t e d cable. In

most systems the 200 ohm impcdpace gives a high fidelity

circuit nzum is that continued operation is possible during

nn accidmtrl system ground fault. This awidmtal

bmndwidth with low lwsar.

 

grounding uo happm whea a wire is pinched or a cable

When using equipmeat in nia or conditions of excessive

scraped.erossasbprpedge. Oncrceidentalgrwndcmb

moisturr, always protect the equipment with plastic covers

t o l d by the system until the fault can be cleared md

(with luck) b c f m a sccolld ground fnult can cause noise or

md make sure uU cable c~ll~ectcnsme lifted out of mud,

overload or bring the system down.

mow or moisture md pmtected with plastic. Wpter mud

d s n o w i n ~ ~ ~ ~ c p n c a ~ s ~ n o i s e .

 

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Contents Rtstm Proprietary Notice CM3001RMUWBlock Disgram Description Users are talking eonf&gFymiii Using two win able. P o r n is Suppliedbyabatteryoraloulpowgsupply.~ C M H K l l R M 3 0 0 c m b e ~ e d i n a l t h r e e ~ StpuatefromtheaudiodsuppliedcmtnllyTheluorstltiontodnwmncwrrntfromthepower Their weight, padding and dssignLowilqdmceandcanbetlnneduploud Theimpdwxhasalargerefhxtwith~tdaybeulsttsWirsri?rcddsrrninssthe~opwrtingdist.nCc Ths CM300URM300L with 25 ohm~ t o ~ t ~ i n t o & e q u i p m m t s u e b a s TV amsns yet high amugh to minimirs extendWiring Diagnm at back of mmd T h e I W I n ~ s y s t e m d ~ s l u r o s c o m m mAnd~elillgsbidddninwinswithcircuitrchunwirrs I a g ~ u s a ~ o n s w i l h t h r e e ~ m d t h l mP i d Openting Envircammts Blaring RdioAuto on Highway Muimum AUomb1.3Fmnt Panel, Model CMUO/RM300 User Station A c u b o n m i ~ s m u l . t s t y p e b s p d p e t CALLplshbottonCARBonMICrophooc AS1409 B Assembly Diagram, P.C.B. CCW45Layout Sectim 7 Diagrimsi DrawingsTM1786 Volt Battcry Opedon / Tckpmdoctim Systean Exampk SD14640D2993, Outline Drawing, CM3OO Page Cable Wiring D i ,T h Channel Systen Page Page Page Page21 Page Page Page Mraarrsra