Collcomm NCS-C151 User manual

NCS-C151
INSTRUCTION MANUAL
Rev B
Collcomm Inc.
d.b.a. NCS
Shipping Address
2310 Pendley Road
Cumming, Georgia 30041
Mailing Address
1595 Peachtree Parkway
Suite 204-123
Cumming, Georgia 30041
Toll Free Tel. & Fax : [phone]
Email : [email protected]
Web Site: www.collcomminc.com
collcomm inc

NCS-C151 Manual Rev B Page 2
Revision History
Rev
Description
Date
App’d
0
Initial Release
07/14/14
JFP
A
Corrected for Trunking Radio on RAD1;
Added Tx Audio Levels; corrected DC
wire size & current consumption
1/7/16
JFP
B
Removed 125mVpp AGC Reference
3/27/17
JFP
Model No.: NCS-C151
Serial No. : ___________________________
Accessory Kit
Item # Description QTY
1 10’ DC Power Cable (NCS-410-PSP-10) 1
2 Mounting Feet 4
3 Mounting Bracket Kit 1

NCS-C151 Manual Rev B Page 3
Table of Contents
Section Description Page
1.0 Introduction 4
2.0 Safety Information 4
3.0 Front Panel Controls 5
4.0 Radio Requirements 5
4.1 Receive Audio 5
4.2 Transmit Audio 5
4.3 PTT 5
5.0 Power Supply 6
5.1 Power Requirements 6
5.2 Power Connection 6
5.3 Polarity 6
5.4 Fusing 6
6.0 Opening Unit to Perform Adjustments 7
7.0 Internal Setup and Adjustments 8
8.0 Trunking Delay Operation 10
9.0 Radio Interface Cables 11
9.1 Radio Interface and AUX Jack Pin-outs 12
10.0 Troubleshooting 13
11.0 Contacting NCS 14
12.0 C151 Specifications 15
13.0 Warranty 16

NCS-C151 Manual Rev B Page 4
1.0 Introduction
The C151 provides a method of connecting two radios together for purposes of
in-band or cross-band repeating.
Almost any radio can be used with the C151. Either VOX or COR can be used
as a “busy” signal and COR polarity can be either + or -. Receive audio levels
do not need adjustment due to built-in AGC circuits for both radios. Transmit
audio levels can be adjusted independently for each radio.
A separate record output is provided that records audio transmitted on either
radio. A record control output is included to control an external recorder.
Typical Application
Conventional Radio –RAD 2 Trunking Radio –RAD 1
2.0 Safety Information
The C151 is an electrical device requiring appropriate safety measures during
installation and operation. The following safety precautions should be
observed:
When connecting the unit to a DC power source, a minimum wire size of
24 AWG should be used. When using in a mobile environment,
automotive grade wire should be used.
Do not route cables or wires through areas that may cause the insulation
to be worn resulting in shorting of the wires to ground or to each other.
Do not attempt to operate this equipment while driving a vehicle. For
safety, pull over to the side of the road when making adjustments.
NEVER connect this device to an AC voltage source. Death or injury could
occur and/or the unit can be badly damaged. Connect this device only to a
DC power source with a voltage output of 9-16 volts and a current
capability of at least 100 ma.

NCS-C151 Manual Rev B Page 5
3.0 Front Panel Controls
4.0 Radio Requirements
4.1 Receive Audio
Receive Audio input levels from the radio are not critical. The Busy lights
activate (when using VOX) at approximately 150mV. Receive audio input
levels are automatically adjusted by an AGC circuit. The AGC circuit for
each radio will produce an output of 1.25Vpp.
4.2 Transmit Audio
Transmit audio levels are separately adjustable for each radio and
sufficient gain is available to drive nearly any radio.
4.3 PTT
PTT is via an Open-Drain output. This signal pulls the PTT line of the
radio low and will key any radio with a low-true PTT requirement.
Maximum switching capacity of the PTT output is 100V, 1.5A DC.
Item
Description
1
Power Switch with Green Indicator
2
Delay Circuit Power Indicator
3
Audio Delay Set Pot
4
Radio 1 & 2 Indicators: Red = Transmit and Green = Receive
1 2 3 4

NCS-C151 Manual Rev B Page 6
5.0 Power Supply
5.1 Power Requirements
The NCS-C151 will operate with any 9-16 VDC power supply capable of
providing at least 100mA continuous.
5.2 Power Connection
Power is supplied to the cable on the rear of the unit. The connector is an
AMP/Tyco Right Angle Two Conductor (P/N 1-770966-0)
5.3 Polarity
Power cable polarity is: Red = +, Black = - (or chassis).
5.4 Fusing
The C151 uses an internal self-resetting fuse. If the fuse opens, there is
likely to be an internal malfunction and the unit should be repaired by a
qualified technician.

NCS-C151 Manual Rev B Page 7
6.0 Opening Unit to Perform Adjustments
Follow the procedure shown below to open the unit up to perform settings and
adjustments:
Rear View of Unit –locate 4 screws
1. Remove 4 screws, rear panel & bezel
2. Slide the whole assembly (both circuit card assemblies) out of the
enclosure. Be careful to secure both boards.
3. Ready for Adjustment

NCS-C151 Manual Rev B Page 8
7.0 Internal Setup and Adjustments
The lower of the two printed circuit board assemblies inside the C151 has
provisions for setting up COR/VOX, COR Polarity and VOX Hang time. To
setup these functions, remove the rear cover of the C151, slide the PCB
Assembly (2 Boards) out of the enclosure and refer to the diagram below
(the lower of the 2 boards) for the locations of settings and adjustments.
The top board does not require any adjustments.
Radio 1 Receive Setup and Transmit
Audio Level Adjustments
Radio 2 Receive Setup and
Transmit Audio Level Adjustments
Record Output Level
Adjustment
Factory Installed Shunts & cables on
Internal Board Connector EXCEPT
POSITION 1.
RADIO1 Setup switches set for Low-
going COR (COR- = ON) and normal
Hang-time (LOW-HANG = OFF).
RADIO2 Setup switches set for Low-
going COR (COR- = ON) and normal
Hang-time (LOW-HANG = OFF).

NCS-C151 Manual Rev B Page 9
7.1 Connect one radio to the RAD1 jack and the other radio to the RAD2 jack
on the rear panel of the C151 using radio-specific Radio Cables. Connect
the power cable to 12VDC.
7.2 Set the COR, VOX and Hang-time settings as required for each radio.
7.3 Turn On the Power switch. The Green “ON” indicator should illuminate.
7.4 Transmit a signal to the radio connected to the RAD1 jack. The green
BUSY indicator for RAD1 should light up and the red TX indicator for RAD2
should light up. This will cause the radio connected to the RAD2 jack to
transmit. Adjust the RAD2 TX level control using a service monitor or another
radio. Stop transmitting.
7.5 Transmit a signal to the radio connected to the RAD2 jack. The green
BUSY indicator for RAD2 should light up and the red TX indicator for RAD1
should light up. This will cause the radio connected to the RAD1 jack to
transmit. Adjust the RAD1 TX level control using a service monitor or another
radio. Stop transmitting.
7.6 This completes Setup.
7.7 Reinstall the two (2) circuit board assemblies inside the enclosure as
follows:
1. Slide the bottom circuit board into the SECOND from the BOTTOM
SLOT on the rear of the enclosure. Slide the top circuit board into the
FOURTH from the TOP SLOT on the rear of the enclosure. Make
sure both sides of each circuit board slide into the corresponding slot
on each side of the enclosure.
TOP Board (4th slot from top)
BOTTOM Board (2nd slot from bottom)

NCS-C151 Manual Rev B Page 10
2. Slide the assembly all the way into the enclosure making sure the
power switch fits through the hole on the front panel
3. When the assembly is all the way into the enclosure, re-install bezel,
rear panel and tighten 4 screws.
8.0 Trunking Delay Operation
8.1 Overview
The NCS-C151 is equipped with a Trunking Delay Module connected to Radio
1 (RAD 1). The purpose of the circuit is to delay the transmitted audio and PTT
release while the Trunking Radio acquires a channel from the Trunking Radio
System controller. This prevents voice transmissions from being lost or
“chopped” during the channel assignment (trunking handshake).
8.2 Setup and Operation
The delay module has an adjustment on the front of the NCS-C151 for setting
the total Trunking Channel Acquisition delay. Turn this control using a small
screwdriver to equal or exceed the maximum delay expected from the trunking
system. Available values (also shown on the unit’s front panel) are: 0ms (no
delay), 50ms, 100ms, 200ms, 400ms, 800ms, 1600ms and 3200ms.
During operation, when the trunking radio is keyed from the C151, the radio will
key for at least the set delay period plus the length of the receive audio time
from RAD 2 (the audio from RAD 2 will be transmitted complete after the time
of the delay set).

NCS-C151 Manual Rev B Page 11
9.0 Radio Interface Cables
A Radio Interface Cable is required for each radio interfaced to the C151. This
cable contains mic audio, receive audio and PTT signals. It can be fabricated
from the documentation supplied in the instruction manual or obtained from
NCS. The cable consists of an RJ-45, 8 pin modular connector on one end for
mating to the C151 and a radio interface connector on the other end. Un-
terminated cables are also available that require the customer to attach the
radio interface connector.
Most commercial radios have an accessory connector that usually has mic
audio, receive audio and PTT connections available. This is the preferred
interface to the NCS-C151.
Specifying Radio Interface Cables
NCS can supply Radio Cables for almost any radio. Standard cable length is
six feet, however, custom lengths are available. Since there are numerous
connector types for interfacing to various commercial and amateur radio
transceivers, the radio model and connector type should be specified at the
time of purchase.

NCS-C151 Manual Rev B Page 12
9.1 Radio Interface and AUX Jack Pin-outs
RJ45 RAD and AUX Connector Pin-out
NAME
PINOUT
RAD1,
RAD2
RJ45
Conne
ctors
on
Rear
Panel
Pin
Signal
Note
1
TX AUDIO
To Radio Mic Input
2
TX AUD
COMMON
To Radio Mic Input Common or Gnd
3
PTT
To Radio PTT Input
4
GND
Signal Ground
5
RX AUDIO
From Radio Audio (Speaker) Output
6
GND
Signal Ground
7
----
Not Used
8
COR
In From Radio
AUX
RJ45
Conne
ctor on
Rear
Panel
Pin
Signal
Note
1
DISABLE_1
Not Used
2
DISABLE_2
Not Used
3
GND
Signal Ground
4
EXT_P4
Spare/Factory Use
5
RECORD
OUT
RX AUDIO MIXED FROM BOTH RADs
6
GND
Signal Ground
7
RECORD
PTT
KEYS EXTERNAL RECORDER WHEN
EITHER RAD IS BUSY
8
EXT_P8
Spare/Factory Use

NCS-C151 Manual Rev B Page 13
10.0 Troubleshooting
The C151 was designed with care and uses high quality components and
construction. You should not experience any operating difficulties when you
follow the setup and use instructions in this manual. If you do experience
problems, here is some information that may help you resolve the issues.
Hum
Magnetically induced hum can be caused to any modern piece of audio
equipment by too close proximity to unshielded power transformers or other
equipment that radiates strong AC magnetic fields. You can tell if you have this
type of hum by rotating the C151 left/right, up/down and moving its position. If
the hum increases and decreases, then you are experiencing magnetic
coupling from an unshielded power transformer or other equipment. The C151
should be several inches away from equipment that radiates AC magnetic
fields.
Another source of hum can be a ground loop. This is a situation when pieces
of audio equipment that are connected together do not have their grounds well
connected. This results in a voltage difference between the equipment grounds
and can be a safety hazard as well as introducing electrical problems. The
solution to this problem is to tie all your equipment grounds (usually case or
chassis) together with a low impedance RF connection. The best choice for
connecting material is a wide braid or copper strap.
Noise
Excessive noise can be caused by many factors. The C151 uses state-of-the-
art low noise amplifier ICs. However, even these components can add a bit of
noise or “hiss” to an audio signal if not adjusted properly. If you seem to have
excessive “hiss” type noise, review the setup and level adjustments you’ve
made to the C151 In some cases, increasing the radio’s own mic gain and
decreasing the levels from the C151 may improve the noise level.
Excessive noise can also be caused by ground loops. See the previous “hum”
discussion for information on eliminating ground loops.
Distortion
Distorted audio can be caused by one of two situations. The first and most
common is improper adjustment of audio levels. Be sure you’ve adjusted the
Radio and C151 level controls as recommended in this manual and that your
radio’s mic gain control is properly adjusted. Setting the Volume Controls at
too high a level can also cause distortion.
RF at the operating position can also cause distorted audio. To determine
whether this is the problem, connect your transmitter to a dummy load. If the
distortion disappears, then you have RF entering the interface cables. To
eliminate RF problems, first make sure you have set up the jumpers and radio
cables correctly. Then check that you have a good ground between all pieces
of equipment and that your RF ground is low impedance.

NCS-C151 Manual Rev B Page 14
In-band Repeating
In-band repeating requires special attention to prevent one radio from
interfering with or desensitizing the other. Many techniques are available
including increasing vertical and horizontal separation of antennas, shielding
one antenna from the other and using different polarizations for each antenna.
The specific solution will be determined by the installation environment and the
overall operation conditions. Experimentation will be required.
11.0 Contacting NCS
NCS wants you to experience trouble free operation of our equipment. If you
have any questions, comments or need technical help, please use the following
resources:
1. Go to the web site, www.collcomminc.com. Here you will find the latest
instruction manuals, any factory developed modifications and Frequently
Asked Questions. Schematics for all NCS products are available. Please
inquire.
2. Email us at [e-mail]. Be sure to include all pertinent
information, e.g. make and model of radios, how they’re connected to the
C151, detailed description of any problems, antenna and grounding
configurations, etc.
3. Telephone us toll-free at 888-883-5788.
Note: Be near your equipment and have the manuals for your radios
available. We will do our best to help you using our technical expertise.

NCS-C151 Manual Rev B Page 15
12.0 C151 Specifications
General
Dimensions
2.1"H x 4.1"W x 5.0"D
5.3cm x 10.3cm x 12.0cm
Weight
1.0 lb (0.45kg)
Temp Range
-20°C to + 65°C
Power Requirements
9 to 16 VDC @ 100mA max. Nominal 12VDC @ 100mA
9VDC Battery:
Type
Total
Capacity
Estimated Max
Runtime
Standby
Estimated Max
Runtime
50% Duty Cycle
Carbon-
Zinc
400 mAh
TBD hours
TBD hours
Alkaline
565 mAh
TBD hours
TBD hours
Lithium
1200 mAh
TBD hours
TBD hours
Front Panel
Power On/Off
Toggle Switch with Green LED Indicator
Indicators
Green LED "Busy" Indicator and Red LED "Transmit" Indicator
for each Radio
Delay Set
Adjustable pot for fixed interval delay settings from 0 to 3200 ms
Rear Panel
Radio IF Connectors
RAD1, RAD2
RJ-45 Modular Jack
AUX
RJ-45 Modular Jack
DC Power
AMP/Tyco 2 Cond, Rt Angle P/N 1-770966-0
Signal Levels
COR from Radio
COR + → Active High
COR - → Active Low
Low = < 1.0VDC; High >2.0VDC
PTT to Radio
Active Low, <.5 Ohm @ 1A, Max Rating 1.5A, 100V
TX Audio
Adjustable, 0 → 1.25Vpp or 0-125mVpp (See page 2)
RX Audio
Speaker or Line Out from Radio, 75mVpp → 5Vpp

NCS-C151 Manual Rev B Page 16
13.0 Warranty
All products manufactured by Collcomm Inc. (hereafter referred to as NCS) and purchased
from an authorized dealer or purchased directly from NCS will be warranted to be free from
defects in material and workmanship for a period of one (1) year from the date of purchase.
NCS' liability under this warranty and the Customer's exclusive remedy is limited to
repairing, servicing or adjusting, and/or replacing the defective product returned to NCS
within the warranty period. Whether the defective product is repaired or replaced will be at
the sole discretion of NCS. The warranty will be voided for products that have been abused,
misused, or subjected to abnormal operating conditions as determined by NCS. Further,
products damaged by lightning, power surges or force majeure events are not covered under
this warranty.
If, in the Customer's estimation the product appears to be defective and is within the warranty
period NCS should be notified as to the nature of the defect. If the product appears to be
covered by the terms of the warranty, NCS will promptly communicate a return authorization
number and shipping instructions to the Customer. When returning a product for
repair/replacement under warranty the proof of purchase or a copy thereof must be returned
with the defective product. NCS at its discretion may deny warranty in the absence of proof of
purchase. Acceptable proof of purchase includes bill of sale, cancelled check or credit card
receipt. Evidence of alteration of the proof of purchase document shall be reason to
immediately void the terms of the warranty.
For those products returned that prove to be defective and covered under the warranty, the
Customer will bear the cost of shipment for the return of the product to NCS. Collect
shipments will not be accepted. NCS will bear the cost of shipment for return of the product
to the Customer after repair/replacement. Mode of shipment for return to the Customer will be
determined by NCS. Should examination reveal that the product is not defective, NCS will
notify the Customer and request return shipping instructions and NCS will be due all shipping
expenses. In the event that the examination reveals that the product is defective, but for any
reason is excluded from this warranty, NCS will prepare a quotation of the cost to repair, and
will communicate same to the Customer. In the latter event, NCS will be due all shipping
charges incurred for return of the product to the Customer.
The Customer may attempt to repair a defective product under warranty provided
authorization to do so is received from NCS Technical Support. NCS will supply replacement
parts free of charge for authorized Customer repairs provided that the defective part along
with the proof of purchase is submitted to NCS. NCS will pay postage and handling for
replacement parts provided the above terms are met. The product warranty under these
circumstances will remain in force for the life of the warranty.
EXCEPT FOR THE EXPRESS WARRANTIES STATED IN THIS WARRANTY, WHICH
ARE EXCLUSIVE, NCS DISCLAIMS ALL WARRANTIES ON PRODUCTS SOLD
HEREUNDER, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE. UNDER NO CIRCUMSTANCE IS NCS
LIABLE FOR CONSEQUENTIAL DAMAGES TO PERSON OR PROPERTY AS A
RESULT OF THE USE OF ANY NCS PRODUCTS.
The Customer may have additional rights beyond those specifically outlined in this document
based on individual state laws.