Communications Company IC-29 User manual

9181 Chesapeake Drive • San Diego, CA 92123 • [phone] • Fax [phone]
IC-29 Manual PC
Rev E 1/31/00
www.commcoinc.com [email protected]

IC-29 MANUAL
ELEMENTS
Table of Contents
Becoming Familiar With The IC-29........................................................................... 1
Specifications ......................................................................................................... 1-2
Front Panel Controls and Indicators .......................................................................... 3
Rear Panel Connections ........................................................................................... 4
Jumper Settings...................................................................................................... 5-6
Initial Setup and Adjustment Notes............................................................................ 7
Option Boards, Installing an Option Board................................................................. 8
Optional Notch Filter Setup, 120/240 Volt Setup ....................................................... 9
Common Setups For the IC-29 -or-
How to Install an IC-29 Without Reading This Manual ....................................... 10-17
Speaker to Speaker Application ................................................................... 11
Ticket Window Application ........................................................................... 12
Cath-Lab w/Headset Full Duplex Application ............................................... 13
Multi-Cell Monitoring Application .................................................................. 14
Drive-Though Application............................................................................. 15
Drive-Though Multiple Inside Station Application......................................... 16
Guard/Handset Intercom Application ............................................................ 17
Troubleshooting Hints ............................................................................................. 19
Glossary of Terms............................................................................................... 20-21
Configuration Notes................................................................................................. 22
Vox Operations Notes.............................................................................................. 23
Appendix A - Schematics ........................................................................................ 24
Functional Block Diagram ................................................................................ i
Inside Microphone Pre-Amp ........................................................................... ii
Inside Gain & Limiter.......................................................................................iii
Inside Power Amp...........................................................................................iv
Outside Microphone Pre-Amp......................................................................... v
Outside Gain & Limiter....................................................................................vi
Outside Power Amp.......................................................................................vii
Vox & Anti-Vox..............................................................................................viii
Push to Talk/Listen .........................................................................................ix
Shutoff Logic................................................................................................... x
Call Circuit ......................................................................................................xi
Power Supply ................................................................................................xii
IC-29NF Notch Filter.....................................................................................xiii
IC-29DB Delay Board ...................................................................................xiv

Page 1
COMMUNICATIONS COMPANY  IC-29 Manual
BECOMING FAMILIAR WITH THE IC-29
Congratulations on your purchase of the IC-29 universal, 2-station intercom. It can be used with industry
standardmicrophones,speakersandbuttons, or Communications CompanyIC-29Accessories(Seethe
information sheet called IC-29 Accessories). The IC-29 is actually two separate amplifiers, joined by a common
control section and can be used in many different setups - from fast-food drive-up windows, to prison visitor
booths, to hospital Cath-Lab's. Your IC-29 is capable of almost any application or setup you, or your customers
canimagine.
IC-29DESCRIPTION(Sortof Technical)
The IC-29 is a universal two station intercom. All configurations are supported; push to talk, privacy, duplex,
etc. However, the unit is optimized for VOX (voice actuated, hands-free) operation. The unit consists of two
complete audio sections and a common control section. The IC-29 incorporates several unique features. It
has an output amplifier that, when “OFF”, has a very high output impedance so the speaker may also be used
as a microphone without the need of switching contacts. It also has a limiter/volume control that prevents
overload from unusually loud inputs. The changeover circuits are designed for either VOX operation, push to
talk, or combinations to afford maximum versatility. A call feature is also included to both alert the user and
wake up the system if it is turned off. Indication circuits are provided to enable easy testing and setup. User
functions are remotable through D.C. controls. Optional accessory boards provide audio delay in the talk
circuit to assure the VOX can operate without clipping words, and a dual tunable notch filter in the listen circuit
toreducefeedback.
IC-29SPECIFICATIONS(VeryTechnical)
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Page 2
COMMUNICATIONS COMPANY  IC-29 Manual
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Page
COMMUNICATIONS COMPANY  IC-29 Manual
Figure 1 •IC-29 Front Panel
FRONT PANEL CONTROLS AND INDICATORS
The front panel has two sections marked INSIDE and OUTSIDE. Under normal conditions, the INSIDE station
is where the operator is located and the OUTSIDE station is where the customer or public is. The INSIDE knob
controls the audio level inside and the OUTSIDE knob controls the audio level outside.
ACTIVE LIGHT
Near each Level control are red lights marked "Active". When lit, they indicate the IC-29 is sending audio to the
speaker on that side.
LIMITER
There are Limiters provided in each amplifier section of the IC-29. Limiters control the loudest sound that can
come out of the speaker. Turning the "Limiter" control up or down adjusts the loudest sound that will come out
of the speaker. When the red light marked "Threshold" is lit, it shows that the Limiter is triggered and is
reducing the sound level to the level set by the Limiter control. (See the section marked LIMITER SETUP for
moreinformation).
VOX
The IC-29 can be set up to be a hands-free intercom. In hands-free mode, the person on the inside simply
starts speaking, and the amplifier switches over by itself. This is also called VOX mode. The "VOX" light
turns red if the inside amplifier is being turned on by that person's voice. The "VOX" light turns green if the
person is not speaking loud enough to turn the amplifier on.
The Vox control regulates how loud a person must talk at in order to turn the amplifier on. Turning VOX control
counterclockwise decreases sensitivity, thus keeping louder sounds from turning on the amplifier. Turning
VOX control clockwise increases sensitivity, thus allowing quieter sounds to turn on the amplifier. (See Vox
OperationNotessection).
ANTIVOX
Automatic AntiVox is included in the IC-29. AntiVox keeps loud sounds that come through the inside speaker
from turning on the VOX circuit via the inside microphone. The AntiVox light flickers red when Antivox is
active, and turns green when it is not active. Adjusting the AntiVox control changes the amount of sound from
the inside speaker needed to activate the Vox Circuit. (See Vox Operation Notes section).
CALL
The IC-29 features a built in annunciator that uses the inside speaker station as its' signaling device. This
feature is normally used to signal the operator that a customer is at the ticket window or at the drive-up menu
board. The volume of the alarm is controlled by the "Call" control. (See Internal Jumper Settings for more
information)
POWER CALL ACTIVE LEVEL LIMITER THRESHOLD ANTIVOX VOX
INSIDE
MODEL IC-29
DUAL CHANNEL
UNIVERSAL INTERCOM AMPLIFIER
ACTIVE LEVEL LIMITER THRESHOLD
OUTSIDE

Page 4
COMMUNICATIONS COMPANY  IC-29 Manual
R S RVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED PERSONNEL.
SWITCH INPUTS CONTROLS INDICATORS
CALL
ACTIVATE
COM
COM
COM
CALL TALK
LISTEN
VOX INH
SHUTOFF
+
15VDC
-
15 VDC
100 mA
+
10VREF
COM
INSIDE ACTIVE
OUTSIDE ACTIVE
INSIDE
OUTSIDE
+
-
+
-
T
RI SHOCK, DO NOT EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE ." "AVIS:
RISQ
Figure 2 • IC-29 Rear Panel
REAR PANEL CONNECTIONS
The IC-29 has connections on the back that allow the installer to wire switches, lights and volume controls on
panels away from the unit. There are jumpers inside the unit which must be moved in order to activate the
remote volume controls. They are marked IRL and ORL. On the back of the IC-29, there are three control
sectionsmarkedCONTROLS,INDICATORSandSWITCHINPUTS.
CONTROLS section of the rear panel is where connections for remote volume controls are made. The
connections are marked +10VREF,COM, INSIDE, OUTSIDE and CALL. Volume potentiometers (10K Ohm
linear taper) for the inside level, the outside level and the call level are attached here when they need to be
remoted. They are attached across the +10VREF and COM, with the wiper going to inside, outside orcall.
They have the same functions as the volume controls on the front panel.
INDICATORS sectionhasconnections markedINSIDE
ACTIVE and OUTSIDE ACTIVE for remote LED lights to
show which side is active. They have the same function as
the inside active and outside active lights on the front panel.
SWITCH INPUTS section is where the on/off buttons,
talk/listen buttons and footswitches are connected. The
switch inputs are marked CALL, ACTIVATE, TALK,
LISTEN, VOX INHIBIT, SHUTOFF, and COM. The switches
must be connected between any COM input and any switch input. For example, a switch marked "talk" must
be connected to TALK and COM.
SWITCHFUNCTIONS
ACTIVATE Turnson the amplifier. (Outsidemicrophone andinside speaker)
CALL Turnson amplifier, (Outside microphone andinside speaker) and sounds acall tone
throughtheinsidespeaker.
TALK Activates inside microphone and outside speaker (talk mode). Turns on the amplifier
if it is off. Turns off the repeating call tone.
LISTEN Turns on outside microphone and inside speaker (listen mode) if amplifier is already on.
VOX INHIBIT Turns off vox function as long as the switch is on.
SHUTOFF Shuts off the amplifier.
The IC-29 has two connections marked +15VDC and -15 VDC. These provide voltage for future logic on remote
panels or small lights, tone generators, etc., that require less than 100mA of current. Check the current
requirementofyourdeviceor application before connectingitbetweenhereand COM.
LINE IN connections are line-level RCA phono inputs used for connecting
other equipment, such as mixers or wireless headsets, to the IC-29. The
LEVEL trim pots control the amount of line input into the IC-29.
MICROPHONE INPUTS (MIC IN +, MIC IN -, COM, POWER)
Connect your microphone to MIC+, MIC- and COM. POWER supplies
10 Volts to power a condenser microphone, and is returned at COM.
(See PHANTOM POWER in the JUMPER SETTINGS' section.)
SPEAKER OUTPUTS (SPKR +, SPKR -, COM)
Connect your speaker lines to SPKR+ and SPKR-. COM is provided for a shield. If you are using your speaker
asamicrophone(speaker/microphone)connectithere.
(See OUTSIDE SPEAKER ONLY in the JUMPER SETTINGS' section)
DO NOT REMOVE COVER. NO USER
"AUDIO OUTPUTS ACCEPTABLE FOR CLASS 2 WIRING"
INSIDE
(45 ,5 W)
PWR
MIC IN
-
MIC IN
+
COM SPKR
-
SPKR
+
COM
LINE IN
LEVEL
TO REDUCE THE RISK OF ELECTRIC
"WARNING:
DO NOT REMOVE COVER. NO USER SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED PERSONNEL.
115/230 VAC 50/60HZ
22 WATTS
"AUDIO OUTPUTS ACCEPTABLE FOR CLASS 2 WIRING"
INSIDE SWITCH INPUTS CONTROLS INDICATORS
(45 ,5 W)
PWR
MIC IN
-
MIC IN
+
COM SPKR
-
SPKR
+
COM
LINE IN
LEVEL
"AUDIO OUTPUTS ACCEPTABLE FOR CLASS 2 WIRING"
OUTSIDE
(45 ,5 W)
PWR
MIC IN
-
MIC IN
+
COM SPKR
-
SPKR
+
COM
LINE IN
LEVEL
CALL
ACTIVATE
COM
COM
COM
CALL TALK
LISTEN
VOX INH
SHUTOFF
+
15VDC
-
15 VDC
100 mA
+
10VREF
COM
INSIDE ACTIVATE
OUTSIDE ACTIVATE
INSIDE
OUTSIDE
+
-
+
O 115 VAC
O 230 VAC
UL
C
CSA22.2
NO.1
70J6
COMMERCIAL
AUDIO PRODUCT
Model IC-29
UL
LISTED
9181 CHESAPEAKE DRIVE
SAN DIEGO, CALIF. 92123
S.N.
TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE ."
" AVIS: RISQUE DE CHOC ELECTRIQUE - NE PAS OUVRIR ."
"WARNING:
-

Page 5
COMMUNICATIONS COMPANY  IC-29 Manual
ISHPF1
400HZ
ISHPF2
800HZ
IRL
IN REM LEVEL NORM
ORL
OUT REM LEVEL NORM
OUTSIDE
SPEAKER
ONLY
OUT MIC
PHANTOM
POWER
OSO+ OSO-
OSHPF1
400Hz
ON
OFF
OUT ON
IN FOR PRIV
PTL
LSTN
TALK
IRL
IN TO OUT
OPTION I/O
J7
REMOVE JMPR
TO INSTALL
OPTION PCB
OSHPF2
800Hz
REMOVE FOR PRIORITY
IN REM LEVEL NORM
ORL
OUT REM LEVEL NORM
CIS
INSIDE
SPEAKER
ONLY
ISO+
IN MIC
PHANTOM
POWER
ON
OFF
ISO-
ISHPF1
400HZ
ISHPF2
800HZ
INTERVAL
CALL
CIM
CIL
ONE SHOT
REMOVE FOR
REM LEVEL
SWITCH OVER DELAY
REMOVE JUMPERS
TO ADD TIME
200MS
100MS
200MS
IN
IN
OUT
OUT
SPARE JUMPERS
100MS
OUT TO IN
OPTION I/O
J6
REMOVE JMPR
TO INSTALL
OPTION PCB
VCA/LIM OUTSIDE MIC TO INSIDE SPEAKER VCA/LIM INSIDE MIC TO OUTSIDE SPEAKER
COMMUNICATIONS CO. INC.
IC-29 INTERCOM AMPLIFIER
REV E
FRONT
REAR
OUT ON
INTERNAL JUMPER SETTINGS
The IC-29 can be used with many different types of accessories, and can be set up in hundreds of different
ways. This versatility is achieved through the use of jumpers on the inside of the amplifier. A short description
of each jumper is described below.
ORL, IRL (OUTSIDE REMOTE LEVEL AND INSIDE REMOTE LEVEL )
With the jumper in the NORM position, the volume of the amplifier is controlled by the
volume knob on the front panel. When the jumper is in the REM LEVEL position, the
volume is controlled by a remote 10K pot attached to the back of the unit in the
CONTROLS section. (See the Rear Panel Connections section ).
OSHPF1, OSHPF2 / ISHPF1, ISHPF2 (INPUT LEVEL & FREQUENCY RESPONSE)
There are two functions of these jumpers. First, if both on the same side are removed
(i.e. OSHPF1 and OSHPF2) then the microphone input becomes aline level input. If
either jumper is installed, then the microphone input is a mic level input. The second
function is pre-amp equalization. Installing both jumpers adds all the low frequencies to
the mic input. Removing one or the other cuts some of the low frequencies out.
Note: if using a speaker as a microphone we recommend removing the 400Hz jumper.
OUT MIC PHANTOM POWER / IN MIC PHANTOM POWER (ON/OFF)
Jumperforusingmicrophonesrequiringphantompowerwhenusingaseparate
microphone. ONsupplies10 Vdc (commonmode) phantom powerto the microphone.
OFFis usedfor regulardynamic microphones,or electretmicrophones whichrequire a
separatepowerwire.
OUTSIDE SPEAKER ONLY / INSIDE SPEAKER ONLY
Tells the amplifier that the speaker on the outside or the inside will act as a microphone
when no sound is coming out of it. Both jumpers (+ and -) must be in to use this
option. When using a separate microphone, these jumpers must be removed.
OUTSIDE
SPEAKER
ONLY
OSO+ OSO-
INSIDE
SPEAKER ONLY
ISO+ ISO-
OUT MIC
PHANTOM
POWER
ON
OFF
IN MIC
PHANTOM
POWER
ON
OFF
OSHPF1
400Hz
OSHPF2 800Hz
Figure 3 • IC-29 Jumper Location

Page 6
COMMUNICATIONS COMPANY  IC-29 Manual
OPTION I/O (In to Out / Out to In)
Theseare connections foroption boards, insideand outside.
When there is no option board installed, a two pin jumper must
be installed on the right-most pins for the IC-29 to work.
OUT TO IN
OPTION I/O
J7
REMOVE JMPR
TO INSTALL
OPTION PCB
IN TO OUT
OPTION I/O
J6
REMOVE JMPR
TO INSTALL
OPTION PCB
CALL ANNC (ONE SHOT / REM LEVEL / INTERVAL)
With the jumper in the ONE SHOT position, the call tone will sound one time and
stop. When this jumper is removed, the call tone repeats, and is controlled by the
INTERVALjumpers.
The INTERVAL jumpers control the nature of the repeating tone. Removing or
installing jumpers changes the pattern of the repeating tones. Removing all of
them causes the tone to repeat indefinitely, and is not a valid combination.
When "Remove for Remote Level" jumper is removed, the volume of the call tone
is controlled by a 10K pot attached to the back of the unit in the CONTROLS
section. (See the Rear Panel Connections section). When the jumper is installed,
call volume is controlled by the screwdriver adjustment on the front panel.
button is pressed.
Normally, the PRIVACY jumper is out, and the PTL jumper is in. They are
installedthiswayforVOXoperation or push-to-talk applicationswherereturn-to-
listen is wanted, and it allows for change over to be controlled with one "talk"
switch. Confused? See a typical applications sheet that looks like your setup, and
see how they are set.
REMOVE FOR OUT ON
If this jumper is installed, the outside speaker is on ONLY when the inside speaker
is off. When removed, the outside speaker is on whenever the system is active,
andis used for duplex, non-intercom applications.
REMOVE FOR IN ON
If this jumper is installed, the inside speaker is on ONLY when the outside speaker
is off. When removed, the inside speaker is on whenever the system is active,
and is also used for duplex, non-intercom applications
NOTE: When the OUT ON & IN ON jumpers are out, the IC-29 functions as two separate
amplifiers, without common control.
SWITCHOVERDELAY
These jumpers are used to delay the time it takes to switch from Inside to Outside
mode (or vice-versa). They are used to prevent "pop" caused by room acoustics,
or "ringing" from speaker-only setups. Remove individual jumpers to add delay
time. The jumpers marked "OUT" delay the switching of Inside to Outside. The
jumpers marked "IN" delay the switching of Outside to Inside. NOTE: When using
an IC-29DB Delay Board, all switchover jumpers should be in.
PRIORITY (LISTEN / TALK)
These jumpers control which side gets priority in a Push-To-Talk / Push-To-Listen
setup. The LISTEN jumper gives break-in priority to the inside amplifier (outside
microphone),and the TALK jumper gives break-in priority to the outside amplifier
(inside microphone). With both jumpers installed, whichever button is pressed first
gets priority. With both jumpers removed, which ever button is pressed last gets
priority.
IN FOR PRIVACY & REMOVE FOR PTL (PUSH-TO-LISTEN)
These jumpers control a privacy function for the outside station. When the IN FOR
PRIVACY jumper is in and the PTL jumper is out, the Push-To-Listen button must
be pressed to allow the inside speaker to be turned on. -- Sort of like a "Push-To-
Talk" button for the outside station. The Inside station remains on until the TALK
CIS
INTERVAL CALL ANNC.
CIM
CIL
ONE SHOT
REMOVE FOR
REM LEVEL
SWITCH OVER DELAY
REMOVE JUMPERS
TO ADD TIME
200MS
100MS
200MS
IN
IN
OUT
OUT
100MS
LSTN
TALK
PRIORITY
IN FOR PRIV
OUT ON
PTL
REMOVE FOR
IN ON

Page 7
COMMUNICATIONS COMPANY  IC-29 Manual
IC-29 INITIAL SETUP AND ADJUSTMENT NOTES
Your IC-29 is designed to be set up by a qualified installer and should not need to be adjusted, configured, or
altered after initial setup. Your IC-29 should be trouble-free from the moment of installation until the system is
removed. If future adjustments need to be made because of changes in the room (i.e. furniture changes,
carpet, drop ceiling, etc.,) the amplifier can be re-configured without the need to return it to the factory. Just
contact a qualified installer and provide them with these setup notes.
"LIMITER THRESHOLD" AND "LEVEL" CONTROLS
The Limiter threshold is used to set the maximum listening volume of the IC-29. The Limiter can be used to
preventsudden, loudsounds (likedropping a metal pan) from blaring through the speaker on theother side,
whileallowinga suitable volumefornormal conversation.
An assistant is needed for Limiter, Vox, Antivox, and Level adjustments. If no assistant is available, a portable
radio tuned to a news or talk program, set at a low but natural level, can substitute for an actual person. Be
sure to put the radio at a distance from the microphone similar to that of a user. A step ladder may be handy
also.
LIMITER SETUP
Turn the Limiter knob fully clockwise, then adjust the Level knob to a comfortable listening level with no
feedback. Once you are satisfied with the system level, mark it with a pencil, and begin to turn the Limiter
control counterclockwise until the red "Threshold" light begins to flicker. That's all! Now do the same for the
other side, and you're done. With these settings, the signal compression and gain are ideal. There will be
minimalbackground noise,and sufficient gain to accommodate normal conversation.
NOTE: The user may reduce the volume Level if desired, but if the Level knob is turned past the setting where
it was initially set up, the Limiter will keep the volume down, and heavy compression (and possibly distortion)
will happen. The users should be encouraged to mark the preset adjustment and to leave the Level control set
at that point. If more volume is absolutely necessary, the Limiter setup procedure will have to be done again.
VOX-ANTIVOX SETUP
Accomplish the Limiter and Level setting first, then confirm the jumpers are set for a VOX system. Turn the
INSIDE Level knob all the way down, and both ANTIVOX and VOX trimpots fully counterclockwise. Have your
radio or assistant speak normally on the inside microphone. Turn the VOX control clockwise until the green vox
light begins to flash red. Set the inside level control back to the pencil mark (do not be disturbed if the system
starts chopping). Now advance the ANTIVOX control slowly clockwise until the ANTIVOX indicator is red with
brief flashes of green. When you speak into the microphone, you should easily be able to cause the system to
switch modes.
SWITCH OVER DELAY JUMPERS
NOTE: The outside switchover delay jumpers should never be removed for VOX operation.
Often when the inside user stops talking, there is a "pop" or "bonk" sound. This is especially true if the outside
speaker is also used as a microphone. It may be necessary to extend the switchover delay. This is easily
accomplished by removing the jumpers. First remove the 100 MS jumper (adding 100 MS delay). If this is
insufficient, try the 200 MS jumper or combinations of the two. Always use the minimum delay that is satisfac-
tory.

Page 8
COMMUNICATIONS COMPANY  IC-29 Manual
IRL
IN TO OUT
OPTION I/O
J7
REMOVE JMPR
TO INSTALL
OPTION PCB
IN REM LEVEL NORM
ORL
OUT REM LEVEL NORM
SWITCH OVER DELAY
REMOVE JUMPERS
TO ADD TIME
200MS
100MS
200MS
IN
IN
OUT
OUT
SPARE JUMPERS
100MS
OUT TO IN
OPTION I/O
J6
REMOVE JMPR
TO INSTALL
OPTION PCB
VCA/LIM OUTSIDE MIC TO INSIDE SPEAKER VCA/LIM INSIDE MIC TO OUTSIDE SPEAKER
COMMUNICATIONS CO. INC.
IC-29 INTERCOM AMPLIFIER
REV E
FRONT
Hex Standoff (Typical)
OPTION BOARD
IN to OUT OPTION BOARD
OUT to IN
Option boards are plug-in circuit boards for the IC-29 which allow the installer fast and easy ways to fine-tune a
particular installation site.
IC-29 NOTCH FILTER PCB 12300245-A
FREQ 1
FREQ 2
IC-29 DELAY LINE PCB 12300248
TherearetwooptionboardsavailablefortheIC-29, theNotchFilterboardandtheAudioDelayboard. TheNotch
Filter board provides two screwdriver adjustable filters used to tune out feedback modes and help compensate
forsmallliveroomacoustics . TheNotchFilterboardcanbeinstalledineitherchanneloftheIC- 29. The AudioDelay
board provides 55ms of audio delay in the talk channel (In to Out) for VOX operation in order to avoid chopping
the first syllable speech, this board must mount in the "In to Out" option slot.
INSTALLING AN OPTION BOARD
Installation requires a 1/4" nutdriver or pliers, and a small phillips screwdriver.
1.UnplugtheIC-29.
2. Remove the cover.
3. Locate the option board connector pins. They are in the center, toward the front of the IC-29.
4. Decide on which side you need to install the option board:
IN to OUT. Affects the inside microphone and the outside speaker.
OUT to IN. Affects the outside microphone and inside speaker.
(Usually a Delay Board is installed on the IN to OUT side only.)
5. Install the standoffs supplied with the option boards.
a. Unscrew and save the two phillips-head screws in the IC-29 that will be replaced by the
standoffs. (See figure )
b. Using the 1/4" nutdriver or pliers, screw in the standoffs where you unscrewed the phillips-
head screws.
6. Remove the black jumper on the pins on the right side of the option board connector.
7. Line up the two standoffs and the holes in the option board, and carefully install the option board
on the connector pins, taking care not to bend the pins.
8. Take the two screws you removed earlier and screw them into the standoffs, securing the option
board to the IC-29 assembly.
9. Install the cover back on the IC-29.
IC-29 OPTION BOARDS
NOTE: Option board installation should
only be done by a qualified technician.