Comdel CX600 Series User manual

CX600, FP3113RG
08/25/00 Revise safety section, change AC line input spec to 8A
10/13/99 Changed 25/15 pin adapter Assy
6/10/97 Changed Line cord assy
6/23/97 Added Warning labels, part marking & cosmetic requirements
6/24/98 Added CE mark specific items
CX600S/13.56MHz
RF GENERATOR
Copyright © 2003 by Comdel, Inc.
The information contained in this manual is proprietary to Comdel, Inc. and is protected by copyright and trademark laws.
You may not modify, copy, reproduce, republish, post, transmit, or distribute in any way any material from this manual except as may be
expressly permitted in writing by Comdel, Inc.
Comdel, Inc. •11 Kondelin Road, Gloucester, MA 01930• Phone: [phone] •www.comdel.com

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Table of Contents
I. Safety Information...................................................................2
II. Description / Specifications.....................................................5
A. Electrical Specifications
B. Mechanical Specifications
C. Environmental Specifications
D. Testing Specifications
E. Packaging and Shipping Specifications
III. Unpacking and Inspection.......................................................8
IV. Maintenance............................................................................8
V. Preparation For Use................................................................9
A. Line Requirements
B. Cooling Requirements
C. Installation Requirements
VI. Operating Instructions ............................................................9
A. Local Operation
B. Remote Operation
C. Serial Operation (optional)
VII.Theory of Operation..............................................................13
A. AC Interlock PCB
B. DC Power Supply
C. Oscillator Control Board
D. Driver
E. PA600 Power Amplifier
F. Power Monitor Board
G. CX controller
VIII. Certification.........................................................................16
IX. Chassis Symbols....................................................................17
X. Figures
FP3113RX CX600 Block Diagram
FA0900RX AC Interlock assy schematic
FA0525RX Hall Effect Current Monitor assy schematic
FA0403RX Oscillator Control assy schematic
FA0002RX PA/Driver assy schematic
FA0160RX Directional Coupler assy schematic
FA0606RX CX Interface assy schematic
FA0604RX CX Microcontroller assy schematic
FA0605RX Softkey Input Interface assy schematic
FP3113RX Facilities Control drawing
CPSINTFC CPS Remote Interface

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NOTE: Before installing equipment, carefully read and familiarize yourself with the entire operations
manual. Observe and obey all WARNING and CAUTION notes provided.
I. Safety Information
Warning Label and Safety Marking Explanations:
The following symbols and terms may be found on an instrument or used in this manual.
The CE mark indicates compliance with all currently applicable directives and standards.
This label indicates a general warning or caution condition.
This symbol indicates the presence of high voltages in or around the unit.
This symbol indicates that the component or circuit is short circuit protected.
This symbol indicates the presence of RF energy in or around the unit.
This symbol indicates a protective earth ground connecting point.
This label indicates a
presence of high voltage in or
around the equipment, which
may cause sever injury or
death. All appropriate
precautions should be
observed when installing,
operating or servicing this
equipment.
This label indicates the presence
of Radio Frequency energy in
and around the equipment, which
may cause burns or other
injuries. All appropriate
precautions should be followed
when installing, operating or
servicing this equipment.

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The WARNINGheading used in this manual explains dangers that might result in personal injury or death. Always
read the associated information very carefully before performing the indicated procedure.
The CAUTION heading used in this manual explains hazards that could damage the unit. Such damage may invalidate
the warranty.
MUST–This word is understood to indicate a mandatory condition.
HIGH VOLTAGE–Voltages greater than 50 volts DC or 25volts AC and known to cause death or serious injury if
contacted.
SERVICE–Any operation of maintenance, repair, calibration or similar activity other than the normal operation of the
unit.
QUALIFIED SERVICE TECHNICIAN, QUALIFIED ELECTRICIAN, QUALIFIED PERSONELL –These terms indicate
persons specifically trained to install, service or other wise handle electronic equipment of the character and hazard
potential ofthis unit.
End User Labeling
The system installer should obtain and apply all appropriate safety and warning labels required by the end user’s local
fire department jurisdiction and Occupational Health and Safety Administration over and above those supplied by the
generator manufacturer.
Read And Understand This Section Fully Before Installing or Operating This Equipment.
WARNING: This equipment must be installed, operated and serviced only by trained, qualified persons.
General Safety Requirements
•WARNING: Hazardous Voltages and RF voltages are present inside this unit, which may cause injury or death. To
prevent electrical shock and or RF burns, never operate this equipment with the covers removed. Never operate
without an appropriate cable connected between the RF output connector on the rear panel and the load.
•CAUTION: There are no user or operator serviceable parts inside this equipment. Refer all service to a qualified
service technician.
•This equipment must be bonded to Protective Earth (safety ground) prior to operating the unit. Safety ground
connection must be made at the unit’s rear panel designated 1/4”-20 threaded ground stud. The ground wire
should be a #14 awg or equivalent (minimum) green/yellow lead.
•Replace fuses only with identical type and rating parts. Installation and connection of this equipment must only be
performed by a qualified electrician.
•HEAVY OBJECT CAUTION: A heavy object caution exists for equipment weighing more that
51 lbs or 23 kg. Use lifting aids to install unit, such as chain lifts or hooks and straps, attached to the four handles
at the sides and front of unit. Guide unit intofinal location using care to keep hands and body parts clear of unit.

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CE Mark Specific Safety Requirements
•This equipment meets all applicable safety directives (as specified in prEN50178) required to qualify for the
application of the CE marking.
•This equipment must be installed in accordance with the applicable requirements, or prEN50178 and EN60204-1 /
IEC-204-1.
•This equipment is qualified to operate at Pollution Degree II and Insulation Category II.
•The installation of this equipment must assure that the AC power input connector (UL/CSA) is not accessible to
the user/operator. Access may be gained only by a qualified service technician. AC Mains connector installation
must be in accordance with local requirements.
•This unit provides appropriate separation between all interface, mains and output circuits in accordance with 5.2.18
of prEN50178.
Interlock System
•The low voltage (24 V) safety interlock circuit is designed to disable the unit in the event of an interlock fault
condition. At a minimum, interlock protection is located at the removable top cover, bottom cover and RF output
connector safety cover.
•End user’s system should provide indication to the operator of the interlock fault condition.
•Low voltage powerfor the interlock circuit is supplied by a step down transformer located inside the unit. This
transformer is designed to provide safe low voltage operation and provide isolation from the main AC line.
Lockout/Tagout
Prior to performing system maintenance, repair or other service operations the generator must be locked out and tagged
out to prevent accidentally energizing the system.
The following steps should be performed only by a qualified service technician:
•Disconnect AC input power to the generator.
•Mount a suitable “Clamshell” type lockout device to the AC input plug such as a Hubbell # HLD2 or equivalent.
Follow all manufacturers’ directions for the lockout device.
•Secure the lockout device with anappropriate padlock or safety lock.
•Apply a lockout warning tag to the lock out device.
The Lockout / Tagout device should not be removed until system service is completed and it has been determined
appropriate to reconnect and operate the generator.

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II. Description / Specification
The CX600/13.56 RF amplifier operates at a frequency of 13.56 MHz. The power source produces maximum transfer of
power into a 50 ohm resistive load and is designed to withstand large deviations in load impedance without failure.
The primary features of the CX600 series are its solid-state design, small physical size and reliability.
CX600 series power amplifiers can be supplied with internal frequency sources or may be driven from external
frequency sources having a 50 ohm output and a digital drive level of 0-5 V.
The CX600 series amplifier is constructed with two main sections. The dc power section is contained in the center of
the unit. This section includes the filter capacitor, rectifier and regulators as well as the single-phase 208 Vac power
transformer. These components are operated at about half of their rated outputs to insure the high reliability of this
section. The RF section consists of the internal/external oscillator frequency controlboard (OCB), driver, one PA600
power amplifier on an air-cooled aluminum heat sink, and an output filter/harmonic filter. All components are used well
below their dissipation ratings for long life and low maintenance operation.
A. Electrical Specifications
Nominal Input:
208 Vac, 1 phase
50/60 Hz
8 A
1. AC Input Voltage Range: 190-225Vac; no neutral; single phase with protective earth (PE) ground.
2. AC Line Frequency: 50/60Hz nominal; 47 to 63 Hz range.
3. AC Input Current: 8 amps rms maximum.
4. Output Characteristics:
4.1 0 to 600W continuous forward power at the unit’s rear bulkhead RF connector into a 50ohm load.
4.2 The forward power out is to track the command set point for any load conditions where the
reflected power is less than: 100W.
4.3 Accuracy/Regulation: +/-3.0% of set point, from 10% to 100% max output, as measured by either
the actual output power and/or the forward analog read back signal
4.4 Linearity: +/-3.0% deviation from a straight line for successive requested set point power
increment changes, from 10% to 100% max output, as measured by either the actual output
power and/or the forward analog read back signal.
4.5 Short Term Stability: +/-1.0% for any given output power set point during one continuous hour
of output.
4.6 Long Term Stability: +/-5.0% for any given output power set point during 3 years of continuous
output.
4.7 Rise Time: less than 100ms; from leading edge of enable signal to 90% of power level requested.
4.8 Zero Set point: less than 1.0W actual output power and less than 1.0W read back power when
set point signal is at zero or at a negative voltage.

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4.9 Frequency stability: 13.56 MHz +/-0.005%
4.10 Output Filtering: (for full power into 50 ohms)
Harmonic Signals: less than -30dBc
Spurious Signals: less than -40dBc
AM & FM Noise: less than -40dBc
(@ 50 KHz offset)
5. Protection Features:
5.1 Mismatch Protection: Continuous operation into any impedance mismatch condition without
damage or malfunction; forward power fold back shall occur within 500us if reflected power
exceeds 100W.
5.2 AC Line Protection: A manually resettable circuit breaker on the rear panel opens upon over
current conditions.
5.3 RF Output Power Connection Interlock: A Hard-wired interlock that disables the input AC power
contactor upon removal of the RF output cable.
5.4 Safety Interlock: Disables the input AC power contactor via either of the control I/O connection
signals; open between Pins 11 & 12.
5.5 Over Temperature Fault: Output disabled on high internal temperature.
5.6 Control Signal Protection: Unit not to be damaged if a short circuit or up to 30 volts AC or DC is
placed between any input signal, return signal, and ground.
6. Control Signals
6.1 Signal Input Impedance: 10K ohms, minimum.
6.2 Signal Input Isolation: 1000Vac minimum to the A/C supply line.
7. Rear Panel Electrical Connections
7.1 Input Power Connection: Line cord to be 3’(1 meter), Marinco #306P-AM4
7.2 Output Power Connector: Type "N" female coaxial bulkhead connector.
7.3 Control I/O Connector: 15 pin submin D type (female) receptacle.
8. Control I/O Pinout & Signals (Refer to Figure CPS INTERFACE).
Pin 2: AO, Ref Power Output: 0 to +10Vdc = 0 to 200W linear.
Pin 3: AO, Fwd Power Output: 0 to +10Vdc = 0 to 600W linear.
Pin 4: DI, RF Power Enable, connect tp pin 9 to enables RF output.
Pin 5: AI, Remote Set point Input: 0 to +10Vdc = 0 to 600W linear.
Pin 6: Analog I/O return for Pins 2, 3, & 5 (chassis ground).
Pin 7: DO, RF Power On Output, 5V = RF ON.

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Pin 8: DO, Indicates status of heat sink temperature, LO = HOT, FLOAT = OK
Pin 9: Digital I/O return for Pins 4, 7, & 8 (chassis ground).
Pins 11 & 12: AC Interlock loop, Jump to enable AC power to unit.
B. Mechanical Specifications
1. Size: 19"W x 5.25"H x 16"D (483mm x 134mm x 406mm) maximum dimensions.
Chassis dimensions: 17"W x 5.25"H x 16"D
2. Weight: 36 lbs. (79.2 kg) maximum
3. Mounting: Standard 19" EIA rack mounting adapters with 5.25" front panel.
4. Color and Finish: All surfaces shall be painted or have a coated finish such as gold zinc chromate, gold
alodyne, or equivalent.
5. Handles:
5.1 Front Panel: Two handles (left & right) to be mounted on the front panel exterior, evenly spaced
on center.
6. Front Panel and Indicators and Actuators:
6.1 All front panel indicators will be displayed on a 20 X 2 character alpha-numeric display.
6.2 All settings (in local control mode) will be made from a single rotary encoder or four soft key
actuators.
7. Warning Labels:
7.1 Safety Labels for hazardous voltages, Heavy Object, and Caution for lifting by water fittings are
to be provided on operator visible areas of the generator. IEC standard symbols in user visible
areas for start, stop, enable and cautionary conditions, PE ground, high temperatures and RF
energy present.
7.2 Special marking available at customers specifications
C. Environmental Specifications
1. Operating range: +10 to +40°C (50 to 104°F) ambient, 5-85% R.H. (non-condensing, no formation of ice),
86-106 kPa. Temperature, humidity and air pressure operating range class 3K3 per prEN50178.
2. Cooling Inlet Air: +5 to +35°C max (41 to 95°F)
3. Storage: Temp, pressure & humidity per prEN50178. –25 to +70°C (class 1K4) @ up to 95% R.H. non-
condensing (class 1K3), 70 to 106 kPa (class 1K4).
4. Transportation: Temp, humidity and pressure class 2K3 per prEN50178. –25 to +70°C @ up to 95% R.H.
non-condensing, 70-106 kPa.
5. This equipment has been designed to be compliant with FCC Part 18 emission standards for EMI/RFI
radiation. Radiated emissions shall also not exceed maximum levels permitted by ANSI C95.1-1982

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standards on safety levels with respect to human exposure to RF and electromagnetic fields from 300KHz
to 100GHz.
D. Testing Specifications
1. Production Acceptance Test: Each unit will be required to "pass" production acceptance testing and a
"Final Test Report" will be generated to document results.
1.1 Production Acceptance Testing process shall include as a minimum: Complete
Parametric/Functional Tests covering: line regulation, calibration, linearity, burn-in, over-temp
test, open circuit test, MAX power test, harmonic distortion, AC ripple, and remote interface
tests. Data sheet for each generator to be shipped with unit.
E. Packaging & Shipping Specifications
1. Accessories Supplied
1.1 Final test results
1.2 Operating manual
2. Shipping
NOTE: If there is a conflict between this document and customer Purchase Order then the latter
supersedes.
NOTE FOR REPAIRS:Unless repairs have accessories included with them and have them listed on the
Return Material Authorization (RMA) Tag, returned materials will not have to fulfill procedural
requirements for accessories.
III. Unpacking and Inspection
1. Carefully unpack the unit and inspect for any obvious signs of physical damage that might have occurred
during shipment. Notify the shipping agent of any damage immediately.
2. Check the outside of the unit for missing or loose mounting screws or broken parts.
3. If there is shipping damage or the unit fails to operate properly upon receipt, report damage to the carrier
and Comdel immediately.
CAUTION: Breaking the seal or removing the warranty decal from this unit will void the warranty. If internal
damage is suspected, contact factory for assistance.
IV. Maintenance
The CX600 is designed to operate unattended for long periods of time. Should periodic maintenance or service be
required, it should only be performed by qualified service persons. Contact the factory for maintenance or service
recommendations.

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V. Preparation For Use
A. Line Requirements
The CX600 is designed to operate from a 208 Vac single phase line. The system will still function within
specifications when the line voltage fluctuates between 190 volts and 225 volts. Voltages over the
recommended 208 Vac, however, reduce the safety margins designed into the system and should be avoided.
The system draws a maximum of 8 amps when used to drive a load of 50 ohms. Under conditions of mismatch
the amplifier could draw slightly more current.
B. Cooling Requirements
The ambient air temperature should not exceed 35o C. Sufficient room over the top of the amplifier and along
the sides to permit an unobstructed airflow through the unit is required for proper operation.
C. Installation Requirements
1. This equipment must be install in accordance with the applicable requirements of prEN50178 and EN60204-
1 / IEC-204-1.
2. This equipment is qualified to operate at pollution degree II, installation category II per prEN50178.
3. Power installation is from a single phase (no neutral) 208 Vac source only. For use at other voltages, a
safety isolation transformer must be used in accordance with the requirements of EN60742 /IEC-742.
4. Installation of this equipment must assure that the AC power connector and line cord are not accessible to
the user/operator. Access may be gained only by a qualified service technician. All AC power connections
must be in accordance with local electrical code and safety requirements.
5. This unit provides appropriate protective separation between all interfaces, mains lines and output circuits
in accordance with Section 5.2.18 of prEN50178.
VI. Operating Instructions
The CX600 may be operated either locally at the front panel or remotely through the 15 pin subminiature D connector
(J1) on the rear panel.
A. Local Operation
NOTE: AC interlock Pins 11-12 must be jumped and RF ENABLE Pins 4-9 must be jumped for the unit to be
operated.
1. Check to see that there is clearance around the unit for proper air flow and that a proper RF load is
connected to the RF output connector at rear of unit.
2. Connect unit to 208Vac nominal, single phase and turn on main power breaker at rear of unit.
3. Verify that LED at red pushbutton (AC OFF) marked 'O' LED is on. If LED is off, then check AC line power.
If LED is flashing then check RF output connector interlock switch, top cover interlock switch, or interlock
loop, Pins 11 and 12 of rear panel connector.

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4. Push AC ON green pushbutton marked '|'. The AC ON LED should be illuminated after the mains contactor
closes.
5. The front panel display should show the model/frequency of the unit and the software version number for
the first two seconds. The front panel display should show 'REM' for remote control. Push the mode select
key (>>) on the front panel to select LOCAL control.
6. Enable RF by pushing the blue RF button on the left side of the front panel. The RF button should
illuminate, the display flash 'RF ON', and readings of forward and reflected power should appear. If the
display shows 'CHECK RF INTERLOCK', this means that the RF enable Pins 4 and 9 of rear panel
connector are not jumpered.
7. RF is disabled by pushing the RF button again, by removing RF interlock by disconnecting Pin 4 and 9 of
rear panel connector, or by interrupting the AC mains via the AC interlock loop, the stop softkey, or the
circuit breaker located on the rear panel.
8. The CX600 regulates forward power based upon the setpoint selected by the large data encoder knob on
the front panel.
9. The CX600 can be programmed to linearly ramp up and down the RF output power when RF is enabled or
disabled. This is done by pushing the function select softkey (>) once to adjust the upramp time, and
once more (>) to adjust the down ramp time. The times are programmable from .1 to 10 seconds, in .1
second increments through turning the data encoder knob on the front panel. Pushing the function select
softkey a third time (>) brings the data encoder knob adjustment back to forward power setpoint.
10. An overtemp condition due to improper clearance around the unit or high ambient temperature will
automatically disable RF the CX600. The front panel display will show 'OVERTEMP' for about 2 seconds if
the RF ENABLE softkey is pushed. RF will not be able to be turned on until proper coolant
flow/temperature is established.
B. Remote Control Operation
1-4. Refer to Figure CPS REMOTE INTERFACE DEFINITION for the electrical interface specification. For
remote control operation follow the first four procedures for local control as listed above.
5. Remote operation is the power-up default mode. If the current mode of operation is LOCAL, then push
the mode select key (>>) until the display shows 'REM' in the upper left corner OR restart the unit by
turning AC off then back on.
6. Enable RF by jumping the RF ENABLE pins 4 and 9 of the rear panel connector. The RF button should
illuminate, the display flash 'RF ON', and readings of forward and reflected power should appear.
7. The voltage on Pin 5(+) and 6(-) of the J1 connector will determine the output power level. A voltage of 0
to 10 volts DC across Pins 5 and 6 (chassis ground) will linearly correspond to an RF output of 0 to 600
watts.
8. Reflected and forward power can be monitored remotely through Pins 2(+), 6(-) and 3(+), 6(-) respectively.
Both of these balanced analog outputs are 0 to 10 VDC linearly corresponding to 0 to 200 watts of
reflected power and 600 watts of forward power respectively.
9. An overtemp condition as stated in #10 above in LOCAL will also result in the 'closure' of the
OVERTEMP DIGITAL OUTPUT, Pins 8 and 9 (chassis ground) of the rear panel connector. The digital
output opto-isolator will be turned on.
11. When RF is present at the RF output connector, the POWER ON DIGITAL OUTPUT, Pin 7 will be at
approximately 5V.

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C. Serial Operation (Optional)
The following is a description of the RS-232 ASCII instruction set to operate the CX series of
RF generators. The baud rate is selectable via a DIP switch on the uP control PCB behind the
front panel and is factory set to 9600 baud, N, 8, 1, with echo.
1. All incoming instructions need to be terminated with a carriage return (HEX 'D') except for the ATTENTION
(!) and EXIT (#) commands.
2. The CX interface does not normally require handshaking for it's input because it is interrupt driven with a
1K buffer. Handshake control of it's output is optional.
3. The (PROMPT) response is defined as: <CR><LF> > or HEX D, A, & 3E
Instruction Function Response
! (NO <CR>) ATTENTION (PROMPT)
SPxxxx SET RF POWER (PROMPT)
ER ENABLE RF (PROMPT)
DR DISABLE RF (PROMPT)
P+xx.x SET POWER UPRAMP TIME (PROMPT)
P-xx.x SET POWER DOWNRAMP TIME (PROMPT)
RF READ FORWARD POWER xxxx (PROMPT)
RR READ REFLECTED POWER xxxx (PROMPT)
EE ENABLE ECHO (PROMPT)
DE DISABLE ECHO (PROMPT)
# (NO <CR>) EXIT <CR><LF>BYE
4. Function descriptions:
! -ATTENTION
The '!' command redirects control of the RF generator from either local (front panel) or
analog remote (15 pin 'D' connector) to the serial port (9 pin 'D' connector). There will be
no response from the CX from any other ASCII codes sent while in local or analog
remote modes. Upon receipt of the ASCII '!', the CX will disable RF, set power setpoint
to 0 watts, disable echoing of ASCII characters, and issue a PROMPT. The CX is now
ready to receive ASCII commands via the serial port and will not respond tolocal or
analog remote commands. This command does not require a carriage return <CR>.
SPxxxx -SET RF POWER
This command provides for forward power setpoint (in watts). The syntax allows up to
four digits (xxxx) with leading zeroes OK.
This command only adjusts the setpoint for the CX and does not enable or disable the
RF power.
ER -ENABLE RF
This command enables RF power at the preprogrammed setpoint SPxxxx (SET RF
POWER). The power out will start at 0 watts and increase linearly to the setpointover
the period of time as set by P+xx (UPRAMP TIME).

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If the external RF interlock connection is interrupted (15 pin rear panel analog remote
interface connector), the RF output will not be enabled, and the CX600 will respond with
the message: "CHECK RF INTERLOCK". If RF output is already turned on when the RF
interlock is interrupted, the CX600 will respond with the same message and disable RF
output.
If at any time the CX600 overheats, the unit will disable RF and respond with the
message: "OVERTEMP".
DR -DISABLE RF
This command disables RF power without affecting the setpoint. The power out will
decrease from setpoint to 0 watts linearly over the period of time as set by P-xx.x
(DOWNRAMP TIME).
P+xx.x -UPRAMP TIME
This command allows up to three digits with an optional decimal point (xx.x) to set the
RF power upramp time as described above in the ER (ENABLE RF) command.
The units of time is in seconds and is adjustable from .1 to 10 seconds. The default time
is .1 second unless previously set from either the serial port or local control (front panel).
P-xx.x -DOWNRAMP TIME
This command allow up to three digits with an optional decimal point (xx.x) to set the RF
power downramp time as described above in the DR (DISABLE RF) command.
The units of time is in seconds and is adjustable from .1 to 10 seconds. The default time is
.1 second unless previously set from either the serial port or local control (front panel).
RF -READ FORWARD POWER
This command returns the forward power of the CX.
The returned value can be from one to four digits and the units will be watts. The
PROMPT as described above will follow the value returned.
RR -READ REFLECTED POWER
This command returns the reflected power of the CX.
The returned value can be from one to four digits and the units will be watts. The
PROMPT as described above will follow the value returned.
EE -ENABLE ECHO
This command enables the serial port to echo all ASCII characters sent. The start
default for the echo function is programmable by the serial port configuration switch on
the microcontroller PCB mounted on the back of the front panel, switch #1.
DE -DISABLE ECHO
This command disables echoing of characters.
# -EXIT

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Upon receipt of this ASCII character the CX will disable RF power, set the power
setpoint to zero, issue a "<CR><LF>BYE" response, then redirect control of the CX to
the mode the unit was previously in when the attention command (!) was given. Local
control can now be commanded fromthe front panel mode select button.
This command only functions after a PROMPT and does not require a carriage return.
The '#' will not be recognized buried in or tagged at the end of another command.
The CX will no longer recognize serial port ASCII characters EXCEPT for the attention
'!' character.
VII. Theory of Operation
The CX600/13.56 is a high frequency power amplifier for use in OEM applications. The power sources consist of a AC
Interlock, DC power supply, five stages of gain with associated control systems and monitoring circuits.
The radio frequency signal is generated locally in the Oscillator Control Module. From this module the signal goes to
the driver. The driver further amplifies the signal to approx. 20 Watts to drive the PA600 power amplifier. From the
PA600 the signal is fed through a low-pass filter to remove harmonic content. Forward and Reflected control signals
are obtained from the output signal as it passes through the power monitor board to the output RF connector. The
front panel CX Controller monitors the user input from either the front panel or rear connector, and monitors the control
signals from the RF output power monitor, PA voltage monitor, PA current monitor, and PA overtemp switch. Refer to
Fig 1, CX600 BLOCK DIAGRAM to see how the individual modules are connected together.
A. AC Interlock PCB
The AC mains to the mains power transformer is switched via relay K1, controlled by the AC INTERLOCK
PCB (Figure FA0900RX) mounted on the front panel behind the ON/OFF softkeys. AC power to this interlock
system is supplied by 24VAC transformer which is energized when circuit breaker CB1 on the back panel is
thrown.
The AC INTERLOCK PCB supplies the logic to the AC mains control contactor tostart and stop the CX600
via the front panel softkeys. The PCB's start/stop circuitry is composed of relay logic for safety. The active
circuitry (U1A) causes the OFF softkey lamp to flash if the interlock loop is broken.
The interlock 'loop' for the CX600 includes the rear panel I/O 15 pin 'D' connector, the top cover, and the RF
output connector cover.
B. DC Power Supply
The DC supply consists of a single-phase transformer, full-wave, bridge rectifier and a low-pass filter for the
main power voltages. There are three single-phase bridge rectifiers and filters feeding the positive 15 volt,
negative 5 volt, and positive 5 volt regulators. These voltages are used in the control circuitry.
The outputs of this stage are:
144 VDC Unloaded
37 VDC 25 amps (600W RF output)
1+15 VDC Regulated 250 mA max
1-5 VDC Regulated 250 mA max
1+5 VDC Regulated 1A max

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The high current required by the RF power amplifier (PA) is monitored by the HALL EFFECT CURRENT
MONITOR PCB (Figure FA0502RX) mounted on the 40V DC filter capacitor. This PCB uses a Hall effect
device to monitor the DC current feeding the PA600 RF power amplifier.
C. Oscillator Control Board (OCB)
The oscillator control board (Figure FA0403RX) has six parts, oscillator clock, three stages of gain, circuitry
for output power control and monitoring circuitry. The oscillator clock is a TTL compatible output device that
determines the frequency of operation. This square signal is amplified by three tunedstages of gain,
producing a relatively clean sinusoidal 1 watt output. The DC voltage that powers the last gain stage is
adjustable through control transistor Q5 to control the RF output level of the OCB.
The gain control circuitry smoothes output control and stabilizes output power against line and load
variations and limits output power during high VSWR conditions. Control is achieved through the LM 356
operational amplifier, IC1. This op-amp compares the forward power signal (from the power monitor board) to
that of the DC reference level applied to the non-inverting input. The reference level is set either from the
front panel potentiometer or from Pin 5 of the J1 connector.
The LM 356 drives the gain control transistor, Q5, until enough signal from the forward power detector in the
directional coupler is applied to the inverting input to the op-amp. When the inverting signal equals the
reference voltage on the non-inverting input the drive level holds constant.
The non-inverting input is also the point to which some of the protection circuits connect. The CX controller
pulls this point down when load conditions bring the amplifiers near their over-voltage, or over-current limits.
This limits the drive to the amplifiers until the match between the generator and the load is corrected.
The reflected power limiter performs in the same way when the signal from the reflected power detector in the
directional coupler reaches a pre-set limit. The Q6 transistor does the pull-down function until SWR
conditions are within safe limits. The OCB also includes linearizing circuitry allowing both forward and
reflected analog power level signals to appear at connector J1 as linear presentations of the incident and
reflected RF output power. Two squaring ICs U2 and U4 are used to condition the square law signals from the
directional couplers.
Typical Specifications
(OCB)
Output load impedance 50 ohms
Output RF power level 1 watt (max)
Input power Pin 10 +15 VDC at 170 mA max
Pin 8 -5 VDC at 24 mA max
Remote power control input impedance
Pin 2 on J1 2 K ohm
Reflected power limit Internally set to 100W
D. Driver
The CX600 driver (Figure FA0002RX) is a two-stage Class "C" amplifier with feedback. The first transistor
amplifies a 1 watt (typical) input from the OCB to about 5 watts. The circuitry between the two stages include
two wideband impedance matching transformers and a loss section. The loss section provides added stability
to the system and isolation between stages. The second stage of the driver sends 20 watts (max) to the driver
output connector. There are no adjustments or tuning required for this module.

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Typical Specifications
(Driver)
Gain 15 dB
Input power 1 watt (max)
Output power 20 watts
Input impedance 50 ohms
Output impedance 50 ohms
Collector voltage at full power * 40 VDC
Current at full power * .7 A
* 600 watts into 50 ohm resistive load
E. PA600 Power Amplifier
The PA600 uses four power transistors arranged in two pairs of push-pull Class "C" amplifiers. The input
power from the driver is matched with a wideband transformer, T1. The driver input is then split into two
signals and fed into two push-pull transformers, T2. Each of these transformers drives the bases of each pair
of power transistors, Q1-Q4. The transistors are operated common emitter with feedback.
The collector signals are coupled by a push-pull hybrid combiner, T3. The output of these combiners is once
again added together in a two-way hybrid combiner. There are no adjustments on the PA600.
Typical Specifications
(PA600)
Gain 15 dB
Input power 20 watts
Output power 700 watts (min)
Input impedance 50 ohms
Output impedance 50 ohms
Collector voltage * 37 VDC
Current draw * 25 ADC
* At 600 watt system output into 50 ohm resistive load
F. Power Monitor Board
The power monitor or directional coupler board (Figure FA0105RX) is a detector, which produces voltages
proportional to the square of both forward and reflected power. The signals from the two detectors are
produced from current and voltage taps off the output line. The forward and reflected signals are fed into the
OCB where they are linearized. They are then fed to the CX controller where they are reproduced to the
remote interface connector and displayed on the front panel. The reflected power signal is only present when
the generator is driving a load that is not purely resistive, or not 50 ohms. This signal is also used to drive the
OCB VSWR shutdown circuitry.
G. CX Controller
The CX controller is comprised of four PC boards mounted to the left side of the front panel:
1. CX INTERFACE PCB
The function of the CX Interface PCB (Figure FA0606RX) is to condition all of the analog and digital
inputs and outputs for the CX Microcontroller. This PCB board also provides the protection control

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circuitry to limit forward power in cases of high PA current or high PA RF voltage. This protection
function is handled by U1.
2. CX MICROCONTROLLER PCB
This PCB (Figure FA0604RX), mounted under the CX INTERFACE PCB, contains a 16 bit
microprocessor, memory, digital I/O, and analog I/O to control and monitor all activities of the CX600.
If for any reason the program is terminated or gets lost, the watchdog timer U6 automatically restarts
the system. U6 also monitors VCC for low voltage conditions. If VCC drops below 4.5V, the system
is shut down via uP reset line, U1-71.
If the optional RS-232 serial port is utilized, U7 and associated components supplies the interface.
U14 provides the 5V or 10V reference for the A/D (U11) and D/A (U13) converters.
3. SOFTKEY INPUT INTERFACE PCB
This PCB (Figure FA0605RX) is mounted under the CX MICROCONTROLLER PCB and contains the
softkey sense pads and buffer circuitry to interface all front panel user interface to the CX
Microcontroller.
4. 20 x 2 CHARACTER ALPHA NUMERIC FLORESCENT DISPLAY PCB
This PCB, also mounted under the CX MICROCONTROLLER PCB, provides the display, high
voltage power supply, drive circuitry, and microprocessor to interface the 20 x 2 character display to
the CX Microcontroller data bus.
VIII. Certification
1. This unit carries the ETL safety compliance mark to UL standard UL-1012.
2. This unit is SEMI F47 voltage sag immunity tested.
3. This unit is designed and labeled in compliance with CE mark certification requirements. The manufacturer
will supply a Declaration of Conformity as required.

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IX. Chassis Symbols