A Original
Release

Pub.
No.
86M119


Page ii
Issue
A 1U661-002/-003 COMM / NAV / DME / ADF CONTROL PANEL
TABLE OF CONTENTS
Section
Title
Page
No.
1.0 General Information...........................................................................................2
1.1 Introduction..................................................................................................2
1.2 Description Of Equipment ...........................................................................2
2.0 Installation .........................................................................................................3
2.1 Introduction..................................................................................................3
2.3 Unpacking....................................................................................................3
2.4 Inspection.....................................................................................................3
2.4 Installation Requirements ............................................................................3
2.5 Installation Procedure ..................................................................................3
2.6 Post Installation Check ................................................................................3
3.0 Technical Specifications ....................................................................................6
4.0 Connector Pin List ............................................................................................8

LIST OF FIGURES


Title
Page No.
Figure 1
Installation Wiring Diagram .......................................................5
Figure 2
Outline Configuration .................................................................7


Pub. No.
86M119


Page 1
Issue
A
1U661-002/-003 COMM / NAV / DME / ADF CONTROL PANEL
1.0 GENERAL
INFORMATION
1.1 INTRODUCTION
This manual contains installation information for the 1U661-002/-003 COMM / NAV / DME /
ADF Control Panel manufactured by Sigma Tek, Inc., 1001 Industrial Road, Augusta, Kansas
67010. The 1U661-002/-003 Control Panel is designed specifically to replace older mechanical
Control Panels installed in various 500 series Citation Jets manufactured by Cessna Aircraft
Company.
1.2
DESCRIPTION OF EQUIPMENT
The 1U661-002 Control Panel is designed to provide remote tuning of two VHF COMM
Transceivers, two VHF NAV / DME Receivers and one Automatic Direction Finding (ADF)
Receiver. The Control Panel is capable of tuning within a VHF COMM frequency range of
118.00(0) to 135.97(5) MHz in 25 KHz increments. An optional extended tuning range from
118.00(0) to 136.97(5) MHz in 25 KHz increments is available by jumper selection on the
external J6 connector. The 1U661-003 is identical to the 1U661-002 except the VHF COMM
frequency range is fixed at 118.00(0) to 151.97(5) MHz in 25 KHz increments.
The VHF NAV frequency range is 108.00 to 117.95 MHz in 50 KHz increments. The ADF
frequency range is 190.0 to 1799.5 KHz in 0.5 KHz steps. The capability of pre-selecting
frequencies provide a single level of memory. Up to Ten (10) additional memory channels can
be stored and retrieved with the MEM buttons on the Control Panel. Audio Volume controls
with integrated power Off switch are available for both COMM and NAV radios. Other
ancillary functions incorporated on the Control Panel are; Squelch On/Off, Comm Test, Marker
Sensitivity Hi/Lo, Nav Test, BFO On/Off and ANT/ADF mode selector.
The Control Panel has five (5) dual line, five and a half (5½) digit, Liquid Crystal Display
modules. The displays offer a high degree of readability in bright sunlight, and are backlit for
low ambient light viewing. The top line of each display is referred to as the "Active" display (or
frequency), while the bottom line is referred to as the "Pre-Select" display. Frequency updating
is performed by tuning the knobs associated with the display above it. All updates target the
bottom display line. The Pre-selected frequency is activated by pressing the Transfer (TFR)
switch on the tuning knob stack.
The 1U661-002/-003 has an integrally lighted plastic panel which includes all pertinent
nomenclature required to identify the function of each control. Dimming is controlled by the
aircraft 5 volt DC dimming buss accessed through the rear connector. The nomenclature is
clearly visible in both low and high ambient light conditions.
Internal circuitry of the Control Panel is comprised of five (5) independent Modules, one for
each radio. Each Module is similar in construction, containing three (3) electronic printed circuit
board (PCB) assemblies and a back plane circuit board. One electronic PCB assembly, which is
duplicated in all five Modules, is the micro controller (MCU) board. This board controls the
overall operation of the radio and functions associated with the Module. A second duplicated
PCB assembly is the power supply (PWR) board which provides all necessary voltages for the
Module electronics. The COMM, NAV and ADF Modules contain a third PCB assembly which
serves as the interface board to the NAV and ADF radios.

Pub. No.
86M119


Page 2
Issue
A 1U661-002/-003 COMM / NAV / DME / ADF CONTROL PANEL
2.0 INSTALLATION
2.1 INTRODUCTION
Although the 1U661-002/-003 Control Panel is designed to meet the highest levels of quality and
performance, it can only attain those standards when properly installed. This section provides
the user with practical guidelines to assist in the planning and installation of the 1U661-002/-003
in the flight deck.
2.3 UNPACKING
Use care when unpacking the Control Panel from the shipping carton to prevent damage to the
contents. It is also good practice to save the carton and interior packing material until the unit
has been satisfactorily installed in the aircraft. The original packing material should be used in
the unlikely event that it is necessary to return the unit to the factory.
2.4 INSPECTION
A visual inspection of the Control Panel should be performed to insure that physical damage has
not occurred during shipment. Look over the front of the panel for any chips or scratches. This
includes the displays and all controls. All of the controls should be rotated, pushed or toggled to
ensure proper mechanical operation. The metal cover should not show any dents, and should be
secure. The rear connectors should not show any signs of being damaged along the
circumference. The pins should be visually inspected to insure they are not damaged or bent.
2.4 INSTALLATION
REQUIREMENTS
This Control Panel is intended for use in a cockpit environment. The control panel is mounted to
the instrument panel with seven (7) screws. To ensure proper grounding of unit, all bare metal
mounting surfaces must be clean and free of any contaminants, debris or corrosion.
2.5 INSTALLATION
PROCEDURE
Connect the five (5) circular connectors to the appropriate mating connectors on the back of the
Control Panel. J1 and J2 should be connected to the COMM transceivers, J3 and J5 should be
connected to the NAV / DME receivers, and J4 should be connected to the ADF Receiver. The
COMM1 connector J1 and the ADF connector J4 are identical, so care should be taken to insure
the proper cable is attached to the correct connector.
After the connectors have been checked for successful mating, place the Control Panel in the
opening provided for it. Using the seven (7) screws, securely fasten the unit.
Note: Connector J6 on the 1U619-002 can be used to change the VHF Comm frequency
tuning range. Refer to Figure 1 and J6 Pin List for further details. Connector J6 on
the 1U619-003 Control Panel is not used.

Pub. No.
86M119


Page 3
Issue
A 1U661-002/-003 COMM / NAV / DME / ADF CONTROL PANEL
2.6
POST INSTALLATION CHECK
Apply power to the 1U661-002/-003 Control Panel and the radios. The displays should show the
last frequencies selected when the Control Panel was last powered down. The Comm displays
should show frequencies within the range of 118.00 to 136.97 (or 151.975) MHz. The Nav
display should show frequencies of 108.00 to 117.95 MHz. The ADF display frequencies
between 190.0 and 1799.5 KHz.
To check the Control Panel and associated systems, any of the five (5)
TEST
switches may be
activated. This should cause the activation of all pertinent display segments on the Control
Panel. In addition to activating all display segments, the
TEST
function should also illuminate
the corresponding indicator.
Turn all knobs, and ensure that the appropriate display line is being updated properly. Select
frequencies known to contain information. Verify that the outer (or small) knob operates the
fractional portion of the display while the large, inner knob updates the whole values. A
clockwise rotation of the knobs should cause the frequency to increment, while a counter
clockwise rotation should result in the frequency being decremented.
After selecting the desired frequencies, press the
TFR
switch to swap the values from Pre Select
to Active. The associated radio should tune to the frequency shown in the Active display.
A small knob adjusts the volume level of the audio signal. Clockwise rotation of the volume
knob should increase volume level. The unit is turned off with a full counter-clockwise rotation
(COMM and NAV only).


Pub. No.
86M119


Page 4
Issue
A 1U661-002/-003 COMM / NAV / DME / ADF CONTROL PANEL

COMM 1
RADIO
RADIO
COMM 2
RADIO