R.V.R. Elettronica VJ30000-TE User manual

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
1
TECHNICAL AND MAINTENANCE MANUAL
VJ30000-TE
30Kw Power Tetrode Amplifier 87.5 - 108 MHz
Manufactured by R.V.R. Elettronica - Italy

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
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INDEX
I - PRELIMINARY INSTRUCTIONS AND WARRANTY INFORMATION.......................................................... 4
II - TUBE WARRANTY INSTRUCTIONS................................................................................................................... 6
III – SAFETY REGULAMENT! .................................................................................................................................... 8
CHAPTER 1.................................................................................................................................................................... 12
TX30000-TE GENERAL DESCRIPTION .................................................................................................................. 12
1.1) TRANSMITTER DESCRIPTION ....................................................................................................................... 12
1.2) ELECTRICAL DESCRIPTION.......................................................................................................................... 12
CHAPTER 2.................................................................................................................................................................... 19
ELECTRICAL DESCRIPTION................................................................................................................................... 19
2.1 INTRODUCTION ......................................................................................................................................... 19
2.2 CONSIDERATIONS ON WORKING PARAMETERS .................................................................................. 19
2.3 TUBE ............................................................................................................................................................ 20
2.4 R.F. CAVITY ................................................................................................................................................. 20
CHAPTER 3.................................................................................................................................................................... 36
INSTALLATION ......................................................................................................................................................... 36
3.1 INTRODUCTION ............................................................................................................................................... 36
3.2 UNPACKING...................................................................................................................................................... 36
3.3 ASSEMBLY DESCRIPTION............................................................................................................................... 36
3.4 ASSEMBLY PROCEDURES FOR THE INSTALLATION OF VJ3000-TE ........................................................ 36
3.5 TRANSMITTER CONNECTION TO MAINS VOLTAGE ............................ Errore. Il segnalibro non è definito.
3.5 TUBE INSTALLATION....................................................................................................................................... 38
3.7 TUNING AND SWITCH ON PROCEDURES .................................................................................................... 39
CHAPTER 4.................................................................................................................................................................... 44
MAINTENANCE......................................................................................................................................................... 44
4.1 SAFETY REQUIREMENTS ................................................................................................................................ 44
MAINTENANCE LEVEL 1 ........................................................................................................................................ 44
4.2 ROUTINE MAINTENANCE ............................................................................................................................... 44
MAINTENANCE LEVEL 2 ........................................................................................................................................ 44
4.3 MODULE REPLACEMENT............................................................................................................................... 44
4.4 TUBE REPLACEMENT...................................................................................................................................... 45
4.5 AIR FILTER REPLACEMENT ..................................................................................................................... 45
APPENDIX A.................................................................................................................................................................. 45
CIRCUIT DIAGRAMS, LAYOUTS AND BILLS OF MATERIAL..........................................................................45

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
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PICTURES
FIG. 1 FRONT VIEW DESCRIPTION ........................................................................................................................... 23
FIG. 2 FRONT VIEW .................................................................................................................................................... 24
FIG. 3 REAR VIEW .................................................................................................................................................... 25
FIG. 4 TOP VIEW DESCRIPTION ............................................................................................................................ 28
FIG. 5 PROTECTIONS CARD DESCRIPTION .................................................................................................... 29
FIG. 6 R.F. CAVITY'S FRONT VIEW DESCRIPTION............................................................................................ 30
FIG. 7 WATTMETER VIEW DESCRIPTION........................................................................................................... 31
FIG. 8 R.F. CAVITY LEFT SIDE VIEW DESCRIPTION......................................................................................... 32
FIG. 9 VOLTAGE STABILIZER DESCRIPTION..................................................................................................... 33
FIG. 10 R.F. CAVITY'S REAR VIEW DESCRIPTION .......................................................................................... 34
FIG. 11 DETAIL REFERENCE ................................................................................................................................ 35
FIG. 12 TUBE INSTALLATION DIAGRAM N°1 ................................................................................................. 41
FIG. 13 TUBE INSTALLATION DIAGRAM N°2 ................................................................................................. 42
FIG. 14 TUBE INSTALLATION DIAGRAM N°3 .................................................................................................. 43
FIG. 15 I/O RACK CONNECTORS ........................................................................................................................ 46
FIG. 16 I/O RACK CONNECTORS............................................................................................................................... 47
FIG. 17 REFERENCE VIEW ................................................................................................................................... 48
FIG. 18 R.F. CIRCUIT.................................................................................................................................................... 49
FIG. 19 MEASURE CARD ...................................................................................................................................... 50
FIG. 20 380V CIRCUIT ........................................................................................................................................... 51
FIG. 21 LOW TENSION CIRCUIT ......................................................................................................................... 52
FIG. 22 MEASURE, ALLARMS, LOW-TENSION CIRCUIT............................................................................... 52
FIG. 23 POWER RELAY CARD............................................................................................................................. 53
FIG. 24 REFERENCES VIEW................................................................................................................................. 54
FIG. 25 INTERFACE TELEMETRY CARD.......................................................................................................... 55
FIG. 26 TUNINGS RELAY CARD ........................................................................................................................ 56
FIG. 27 REFERENCES VIEW................................................................................................................................. 57
FIG. 28 POWER SUPPLY P1 .................................................................................................................................. 58
FIG. 29 SECTIONAL VIEW OF THE POWER SUPPLY P1................................................................................. 59
FIG. 30 POWER SUPPLY P2 .................................................................................................................................. 60
FIG. 31 SECTIONAL VIEW OF THE POWER SUPPLY P2.................................................................................. 61
FIG. 32 PROTECTIONS PLANE ............................................................................................................................ 62
FIG. 33 REFERENCE VIEW .................................................................................................................................... 63
FIG. 34 RESISTORS PLANE .................................................................................................................................. 64
FIG. 35 RESISTORS PLANE .................................................................................................................................. 65
FIG. 36 REFERENCE VIEW ................................................................................................................................... 66
FIG. 37 TUNING MOTOR LOAD .......................................................................................................................... 67
FIG. 38 REFERENCE VIEW ................................................................................................................................... 68
FIG. 39 RHEOSTATS ............................................................................................................................................... 69
FIG. 40 REFERENCE VIEW ................................................................................................................................... 70
FIG. 41 PJ1000 PROTECTION SWITCH - PROTECTION FUSES ...................................................................... 71
FIG. 42 REFERENCE VIEW ................................................................................................................................... 72
FIG. 43 INPUT SOCKET......................................................................................................................................... 73
FIG. 44 REFERENCE VIEW ................................................................................................................................... 74
FIG. 45 UTILITIES SOCKET.................................................................................................................................. 75
FIG. 46 REFERENCE VIEW ................................................................................................................................... 75
FIG. 47 HIGHT TENSION PANEL......................................................................................................................... 76
TABLES
TABLE A ELECTRICAL CHARACTERISTICS.......................................................................................................... 14
TABLE B MECHANICAL AND ENVIROMENTAL CHARACTERISTICS.............................................................. 15
TABLE C TRANSMITTER LIMITS ............................................................................................................................. 15
TABLE D READABLE PARAMETERS ON THE FRONT METER PANEL .............................................................. 16
TABLE E READABLE PARAMETERS ON THE FRONT METER PANEL ..............................................................17
TABLE F PROJECT STRUCTURE SPECIFICATIONS ............................................................................................... 18
TABLE G SPECIFICATION OF THE 4CX20000C TUBE............................................................................................ 22

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
4
I - PRELIMINARY INSTRUCTIONS AND WARRANTY INFORMATION
Please observe safety precautions when handling this unit. This equipment contains dangerous
currents and high voltages.
This manual is written as a general guide for those having previous knowledge and experience with
this kind of equipment. It is not intended to contain a complete statement of all safety warnings
which should be observed by personnel in using this or other elettronic equipment.
R.V.R. doesn't assume responsability for injury or damage resulting from improper procedures or
practices by untrained/unqualified personnel in the handling of this unit.
Please observe all local codes and fire protection standards in the operations of this unit.
CAUTION: always disconnect power before opening covers or removing any part of this unit. Use
appropriate grounding procedures to short out capacitors and high voltage points before servicing.
Any damage to the goods must be reported to the carrier in writing on the shipment receipt. Any
discrepancy or damage discovered subsequent to delivery, shall be reported to R.V.R. within five
(5) days from its receipt.
R.V.R. extends to the original end-user purchaser all original manufacturers warranties which are
transferable and all claims are to be made directly to R.V.R. per indicated procedures.
All manufacturers warranties will be supported by R.V.R. to ensure precise and speedy service
where possible.
R.V.R. shall not be liable for any damage of whatsoever nature, arising out of or in connection with
the product or its use thereof.
R.V.R.'s warranty shall not include:
a. Re-shipment of the unit to R.V.R. for repair purposes
b. Any unauthorized repair/modification
c. Incidental/consequential damages as a result of any defect
d. Nominal non-incidental defects
e. Re-shipment costs or insurance of the unit or replacement
units/parts
Warranty shall come into force from invoice date and for the period of the manufactures warranty.

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
5
To claim your rights under this warranty:
a. Contact the dealer or distributor where you prchased the unit. Describe the problem and ask
if he has an easy solution. Dealers and Distributors are supplied with all the information about
problems that may occur and usually they can repair the unit quicker than what the manufacturer
could do. Very often installing errors are discovered by dealers.
b. If your dealer cannot help you, contact R.V.R. in Bologna and explain the problem. If it is
decided to return the unit to the factory, R.V.R. will mail you a regular authorization with all the
necessary instructions to send back the goods.
c. When you receive the authorization, you can return the unit. Pack it carefully for the
shipment, preferably using the original packing and seal the package perfectly. The customer
always assumes the risks of loss(i.e., R.V.R. is never responsible for damage or loss), untill the
package reaches R.V.R. premises. For this reason, we suggest you to insure the goods for the
whole value. Shipment must be effected C.I.F. (PREPAID) to the address specified by R.V.R.'s
service manager on the authorization.
DO NOT RETURN UNITS WITHOUT OUR AUTHORIZATION AS THEY WILL BE
REFUSED.
Be sure to enclose a written technical report where mention all the problems found and a copy of
your original invoice establishing the starting date of the warranty.
Replacement and warranty parts may be order from the following address. Be sure to include the
equipment model and serial number as well as part description and part number.
R.V.R. Elettronica S.p.a. - Broadcasting Equipment -
Via del Fonditore, 2/2c
Zona Roveri
40138 Bologna - Italy
International Phone: +39 - 51 - 6010506
FAX Number: +39 - 51 - 6011104
R.V.R. reserves the right to modify the design and specifications of the equipment in this manual
without previous

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
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II - TUBE WARRANTY INSTRUCTIONS
VARIAN POWER GRID PRODUCT LIMITED WARRANTY
Varian products are warranted to be free from defects in workmanship and materials only. The
warranty involves both calendar time and filament (or heather) operation time. Specifically
involved are: time since the product was shipped from varian time since delivery to the user,
and operation time.
WHICHEVER ELAPSES FIRST CONCLUDES THE WARRANTY.
The warranties are determined by the codes shown in the price schedule.
TIME SINCE TIME SINCE TIME SINCE
SHIPMENT SHIPMENT HEATER-ON
Code from EIMAC To The User Time
T 36 MONTHS 24 MONTHS 10.000 HOURS
R 24 MONTHS 12 MONTHS 5.000 HOURS
P 24 MONTHS 12 MONTHS 4.000 HOURS
N 24 MONTHS 12 MONTHS 3.000 HOURS
K 24 MONTHS 12 MONTHS 1.000 HOURS
L LIFE TESTED AT FACTORY IN LIEU OF AN OTHER WARRANTY
12 24 MONTHS 12 MONTHS
he last category is for hardware or accessory items whwre only calendar time is involved.
An Original Equipment Manufacturer (OEM) or an authorized Varian Distributor can hold an item
in his stock for 12 months and the end user still receiver full warranty. As an example, warranty
code T is for 36 months from the date of the shipment from EIMAC, or 24 months from the date
of delivery to the user,or 10.000 hours of filament-on time, whichever elapses first.
A product which fails (because of faulty workmanship or materials) in the first 10% of the
warranty-time hours will be heither replaced at no charge by Varian or 100% of the purchase price
will be credited through the original authorized Varian Distributor or OEM. If a failure occurs in
the remaining 10-100% of the warranty time hours a prorated adjustment will be calculated and
credit issued. This can only be done through the original OEM or authorized Varian Distributor

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
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A prorated credit is calculated as follows:
Warranty (hours) - Use Time (hours)
= % Credit
Warranty (hours)
Thus for failure Code N (3000 hours) if failure occurred after 600 hours and was found to be
workmanship or materials related:
3000 - 600
= 80%
3000
Tubes being returned on a warranty claim are normally sent to authorized Varian distributor or
OEM from whom originally purchased. If returned directly to the Varian plant of manufacture, the
authorized Varian Distributor or OEM from whom purchased should be notified in case there are
some special instructions.
All products returned on a warranty claim must be shipped via prepaid freight and include a
completed copy of a service report form, a copy of which is included with every shipped product. A
warranty claim cannot be processed without this form. A copy of the original invoice, bill of sale, or
other purchase document should be included with the executed service report form to establish
purchase date and price.
The original Varian shipping carton and packing material should always be used for any warranty
claim return. Shipping damage because of poor packing will normally preclude any warranty
adjustment since the damage will usually make any testing or measuraments impossible.
PARCEL POST SHOULD NEVER BE USED FOR SHIPMENT OF TUBES.

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
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III – SAFETY REGULAMENT!
WARNING!
The currents and voltages in this equipment are dangerous! Personnel must at all times observe
safety regulation!.
This manual is intended as a general guide for trained and qualified personnel who are aware of the
dangers inherent in handling potentially hazardous electrical and electronic circuits.
It is not intended to contain a complete statement of all safety precautions which should be
observed by personnel in using this or other electronic equipment.
The installation, operation, maintenance and service of this equipment involves risks both to
personnel and equipment, and must be performed only by qualified personnel exercising due care.
R.V.R. ELETTRONICA s.p.a. shall not be responsible for injury or damage resulting from
improper procedures or from the use of improperly trained or inexperienced personnel performing
such tasks.
During installation and operation of this equipment, local building codes and fire protection
standards must be observed.
WARNING!
Always disconnect power before opening covers,
doors, enclosures, gates, panels or shields.
Always use grounding sticks and short out high
voltage points before servicing. never make
internal adjustments, perform maintenance or
service when alone or when fatigued.
Do not remove, short-circuit or tamper with interlock switches on access covers, doors, enclosures,
gates, panels or shields.
Keep away from live circuits, know your equipment and don't take chances.
WARNING!
In case of emergency ensure that power has been disconnected.

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
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TREATMET OF ELECTRICAL SHOCK
1) If victim is not responsive follow the A-B-C's of basic life support.
PLACE VICTIM FLAT ON HIS BACK ON A HARD SURFACE
A) AIRWAY B) BREATHING
NOTE: DO NOT INTERRUPT RHYTHM OF COMPRESSION WHEN SECOND
PERSON IS GIVING BREATH.
Call for medical assistance as soon as possible.
2) If victim is responsive:
a. Keep them warm.
b. Keep them as quiet as possible.
c. Loosen their clothing (a reclining position is recommended).
IF PULSE ABSENT, BEGIN
ARTIFICIAL CIRCULATION
APPROX. 80 SEC. : ONE RESCUER, 15 COMPRESSIONS,
2 QUICK BREATHS.
APPROX. 60 SEC. : TWO RESCUERS, 5 COMPRESSIONS,
1 BREATH
LIFT UP NECK, PUSH,
FOREHEAD BACK,
CLEAR OUT MOUTH IF
N
ECESSARY, OBSERVE
FOR BREATHING.
TILT HEAD PINCH NOSTRILS, MAKE
AIRTIGHT SEAL, 4 QUICK FULL
BREATHS. REMEMBER MOUTH TO
MOUTH RESUSCITATION MUST BE
COMMENCED AS SOON AS POSSIBLE.
IF NOT BREATHING, BEGIN
ARTIFICIAL BREATHING
IF UNCONSCIOUS,
OPEN AIRWAY
C) CIRCULATION
CHECK CAROTID PULSE DEPRESS STERNUM 1 1/2" TO 2"

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
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FIRST-AID
Personnel engaged in the installation, operation, maintenance or servicing of this equipment are
urged to become familiar with first-aid theory and practices. The following information is not
intended to be a complete first-aid procedure, it is brief and is only to be used as a reference. It is
the duty of all personnel using the equipment to be prepared to give adequate Emergency First Aid
and thereby prevent avoidable loss of life.
Treatment of electrical Burns
1) Extensive burned and broken skin.
a. Cover area with clean sheet or cloth.
(Cleanest available cloth article).
b. Do not break blisters, remove tissue, remove adhered particles of clothing, or apply any
salve or ointment.
c. Treat victim for shock as required.
d. Arrange transportation to a hospital as quickly as possible
e. If arms or legs are affected keep them elevated.
NOTE
If medical help will not be available within an hour and the victim is conscious and not vomiting,
give him a weak solution of salt and soda: 1 level teaspoonful of salt and 1/2 level teaspoonful of
baking soda to each quart of water (neither hot or cold). Allow victim to sip slowly about 4 ounces
(half a glass) over a period of 15 minutes. Discontinue fluid if vomiting occurs (Do not give
alcohol).
2) Less severe burns - (1st & 2nd degree)
a. Apply cool (not ice cold) compresses using the cleanest available cloth article.
b. Do not break blisters, remove tissue, remove adhered particles of clothing, or apply salve or
ointment.
c. Apply clean dry dressing if necessary.
d. Treat victim for shock as required.
e. Arrange transportation to a hospital as quickly as possible.
f. If arms or legs are affected keep them elevated.

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
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Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
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CHAPTER 1
TX30000-TE GENERAL DESCRIPTION
1.1) TRANSMITTER DESCRIPTION
The TX30000-TE/V1 is an FM broadcast transmitter working in the frequency band from
87.5 MHz to 108 MHz. The transmitter is composed of a modulator (mono or stereo) mod.
PTX30LCD, a driver amplifier mod. PJ1000M and a tetrode final amplifier mod. VJ30000-
TE for the antenna connection.
The transmitter is composed of two 19" racks, 40 HE each, meccanically and electriccally
connected together, so that, when the installation is completed, to realize a single functional
equipment that shows on the right side the driver amplifier, the modulator and the power
supply and service section for final stage amplifier, and on the left side shows the final
amplifier cavity and the general air cooling section.
The final power amplifier uses the tetrode 4CX20000C grounded grids configured with
cathode excitation.
1.2) ELECTRICAL DESCRIPTION
The VJ30000 ia a tube amplifier with utilize the tetrode 4CX20000C grounded grids
configured with cathode excitation.
This amplifier is able to operate with several output max power values but inferior to 27 Kw
continuous with a driver power of about 1000W.
The amplifier show plate pipes, load and input motorised, allowing coverage of the entire
frequency band.
The VJ30000 has been designed to use a 3-phase supply (3-phase option without neutral).
1.3) FRONT PANEL DESCRIPTION
The working parameters values and commands are available separately on each equipment.
About the description of the modulator and driver amplifier see as reference its manual
issued to the transmitter; in fact, these equipment are autonomous and they are only
contained in the complete transmitter rack.
About the final power amplifier are available the readings of the following working
parameters:
A) forward and reflected output power on a single meter, selectable by a selector placed on
the itself meter;
B) control and screen grid currents on a single meter, selectable by a selector placed on the
itself meter;
C) plate current;
D) plate voltage, control grid voltage, screen voltage, filament voltage and filament current
on a single multimeter, selectable by a totative selector placed on the itself multimeter;
E) output cavity air temperature and number of the protection interventions on a alpha-
numeric display at double two digits;
F) indication with the working hours of the tetrode filament on hour counter;
G) active alarm led indications (red color) relative to anomalies caused to excessive plate,
control grid and screen grid currents, excessive reflected power, insufficient control grid
voltage, plate voltage enabled but not present, insufficient air pression in the cavity,
excessive air temperature on the output cavity;
H) INTERLOCK led indicator to indicate the block of the equipment caused to personnel
safety.

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
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I) led indicators as memory of the protection interventions happened (yellow color);
J) led indicator to indicate the voluntary protections service stand-by for short time for a
final amplifier overload.
K) led indicator to indicate the voluntary plate power supply stand-by.
The commands relative the final power stage amplifier are the followings
A) key selector to enable the tunings push buttons;
B) two push-buttons at three positions that allow the setting of the input tuning of the tetrode
amplifier cavity;
C) a push-button at three positions that allows the setting of the frequency tuning of the
tetrode amplifier cavity;
D) a push-button at three positions that allows the setting of the working impedance of the
tetrode anode;
E) a selector at two positions that allows to put in stand-by the tetrode anode power supply;
F) a selector at six positions to select the different measures of the multimeter;
G) a selector at two positions that allows to select the control grid or screen grid current
measures;
H) a selector at two positions that allows to select the forward and reflected power
measures;
I) a key selectro that allows to put in stand-by for a short time the overload protections of
some amplifier’s parameters;
J) a push-button that allows to reset the counting and the memories of the protections
interventions occurred;
K) a push-button that allows to change on the diplay the indication from protection
interventions counter to status of the warm-up timer;
L) a main switch with overload protection that allows to stop the mains voltage to all service
circuits of the amplifier.
Please refer to Table A for the electrical specifications and Table B for the mechanical
specifications.
1.4) PANNEL ALARMS
The panel alarms (fig.2) has numbers indicators of different colors: the red leds point out a
condition of current alarm, the yellow leds show that there has been a condition of alarm
then reentered.
This encircled is characterized by the following protections: excess of VSWR, excess grid
current, excess of anodic current, insufficient power tension, excess of temperature, opening
panel, insufficient ventilation and a key interrupter.
On the panel there are two interrupters, one visualizing the preheating time of valve
filament the second reading the number of reset cycles that the circuit protection has
performed.
Finally a digital display with four digits show the time or the n° of cycles (the two digits of
left), the air temperature of expulsion (°C) (the two digits of right).
Prese, refer to the TABLE A for electrical charcterostocs and the TABLE B for
enviromental specifications.

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
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TABLE A ELECTRICAL CHARACTERISTICS
Power Supply 3-phase with neutral: 380-415V±15%
3-phase without neutral: 208-240V±15%
Manins Voltage Frequency 50-60 Hz
Frequency Range 87.5 - 108 MHz
Tube 4CX20000C
Electrical power consumption
for 25Kw in antenna 51KVA
External Thermal power consumption
for 25Kw in antenna 17Kw
Cosφ0.9
Correct power consumption for phase 32%,32%,36%
Output Power from 500 to 25000W
Antenna Impedance 50 Ohm
No essential emessions less than -85dBc
Frequency Stability 2.5 ppm
Modulation Type F3E
Preenphasis 50 o 75 micro-seconds
selectable
Modulation S/N ratio 82 dB (rms value, dev=±75Khz)
AM synchronous -47dB (mod=400Hz, dev=±75Khz)
AM asynchronous -47dB
Audio MPX input impedance 600 or 1000 Ohm
Audio Channel input impedance 600 or 1000 Ohm
Input audio level fron -13 to +14dB (adjustable)
Channel frequency response from 30 to 15000Hz
Channel distorsion max 0.07% (from 30 to 15000Hz)
Stereo separation greater than 50 dB
Input for SCA or RDS signal n°3
Air cooling Forced ventilation

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
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TABLE B MECHANICAL AND ENVIROMENTAL CHARACTERISTICS
Rack dimensions 565 mm (22.24") W
850 mm (33.46") D
1930 mm (75.98") H
Working temperature from -5° to +45°C
Maximum installation admissible max 95% to 45°C without condensing
Maximum installation height 2500 m
Cooling air volume 3000 m3/h
TABLE C TRANSMITTER LIMITS
Standard tetrode time life=9000 hours at 25KW (maxim 12000 hours)
Power efficiency that depends from the antenna system quality SWR<1.15
Good aspiration air for cooling without impurities
Maintenance aspiration air filters =3 mounths
Very high working noise.

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
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TABLE D READABLE PARAMETERS ON THE FRONT METER PANEL
Output forward power
Output reflected power
Tetrode anode current
Tetrode screen grid current
Tetrode anode voltage
Tetrode filament voltage
Tetrode screen grid voltage
Tetrode control grid voltage
Tetrode driver power
Reflected power of the tetrode input circuit
Power supply current of the solid state PA stage
Power supply voltage of the solid state PA stage
Air temperature of the final stage
Air temperature of the middle stage
Tetrode warm-up timing
READABLE PARAMETERS ON THE EXCITER'S FRONT PANEL
Exciter output forward power
Exciter output reflected power
Working frequency
Audio deviation level for each channel
Modulation level for SCA and RDS inputs
Internal parameters for the various stages of the exciter

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
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TABLE E READABLE PARAMETERS ON THE FRONT METER PANEL
Excessive output reflected power in antenna
Tetrode anode overcurrent
Tetrode screen grid overcurrent
Tetrode control grid overcurent
Final stage overtemperature
Excessive reflected power against to driver
Eccessiva corrente assorbita dal driver
Driver working overtemperature
Insufficient air cooling pression
Service interruptions for not lock rack panels (personal safety)
Total power supply arrest for short circuit
Fuses on each service power supply
Fuses on tetrode filament power supplies
Protection switches for overcurrent on aircooling fans
Excessive reflected power against to exciter
Exciter working overtemperature
Exciter final stage avercurrent
Protection fuses for exciter power supply.

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
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TABLE F PROJECT STRUCTURE SPECIFICATIONS
Amplifier cavity of the tetrode final stage 1/4 tuned with capacitor output coupling.
Grounded-grid configuration of the Final stage tetrode through by-pass capacitors.
Filter for output armonics attenuation the 9th order shunt type at concentraded constants installed
inside of the rack.
Filter for middle stage armonics attenuation of the 9th order at concentraded constants.
Aircooling fans for each equipment.
Power supply with insertion at two steps to limite the insertion overcurrents.
Inductive-capacitor filter on the tetrode anode power supply.
Capacitors for high voltages in film in no PCB oil (no polarized).
Power resistors not connected in series to tetrode anode power supplies of the final stage to limite
the energy of possible anodic discharges.
Stabilized tetrode filament power supply with electromechanical voltage stabilizer.
Single control and screen grid power supply and supplied by electromechanical voltage stabilizer.
Bleeder resistors on both grid power supplies.
Single protection circuits for each equipment.
Overvoltage soppression circuits on data line and internal measures.
Electronic corcuits protect against discharges coming from anode power supply.
Protection circuit against electrical arcs inside the amplifier cavity.
Each device under voltage is protected by fuses.
For personal safety each circuit is interrupted from the high voltage supply.
On the fron panel the general switch interrupts only the line of low power.

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
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CHAPTER 2
ELECTRICAL DESCRIPTION
2.1 INTRODUCTION
This chapter describes, in detail, the operating theory of the VJ30000-TE.
To aid understanding, the unit has been subdivided into modules (fig.1A), each of which is
fully described below.
2.2 CONSIDERATIONS ON WORKING PARAMETERS
The tetrode transmitter is equipped with polarization circuit much versatile that allows to
choise the working Class and the "circulation electrical angle".
When the transmitter is made in the firm is configured in Class B for small power input and
then automatically in Class C for high input power.
This choise allows to obtain the Reflected Power values read on driver not directly
connected with the absolute input reflected power on the tetrode.
The input circuit setting is optimized when the transmitter reaches the programmed output
power; in fact, for lower input power is normal to read reflected power values higher than
the reading on the driver meter.
The transmitter can work with different values of the maximum output power on condition
that lower of 27 KW continuous.
At each power value correspond a better antenna coupling ratio for the best energy
consumption efficency of the equipment.
The best energy consumption efficency of the transmitter is obtained when is evidence a
particular effect of the IG2 current: if the input power increase on the tetrode, there is a big
increasing of the IG2 current but the output power doesn’ t increase more.
A setting in according to the point in which you have the best energy consumption efficency
is advantageus economically, but is dangerous for the reliability.
In fact, if the mains voltage decreases lightly, the transmitter works with the tetrode satured,
with dangerous energy quantity on the harmonic components of the working frequency
present in the RF cavity that can cause electrical arcs with high probability of damage on the
amplifier.
Then, a value of the screen grid current near to the protection threshold could cause
sometimes breakings down of the service.
If the station has a good mains voltage with variations until +/- 7%, the transmitter can be
adjusted with antenna coupling to which corresponds a cavity amplifier efficiency of about
78% (Cavity Efficiency=Forward Power/VA*IA).
When the transmitter works with an high electrical efficiency, the amplifier cavity is tuned
with high Q loaded parameter value.
In This case is necessary to verify that the syncronous amplitude value doesn't increase until
no admissible values.
The operator has a table of characteristics values for the tunings adjusting, but for the great
importance that have some parameters against others, is correct to allow a great choise
freedom and to left to the operator competence the decision about the values to set the
transmitter.

Data redazione: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ30000-TE - R.F. Tube Amplifier
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The limits that mustn't reach are:
- Anode current = 3,6A
- Control grid current G1 = 300mA
- Screen grid current G2 = 300mA
- Output reflected power = 750V with a continuos working of 30KW in antenna
- Anode dissipated thermal power of tetrode > 17KW
- Electrical power consumption efficiency of the amplifier cavity > 80%
The typical working tetrode values for 25KW output power in antenna are:
- Anode voltage = 10700V
- Anode current = 3.10A
- Control grid current G1 = 50-150mA
- Screen grid current G2 = 150-200mA
- Driver power = 900W
When the transmitter is tuned to work correctly at 25KW of output power in antenna, the
final amplifier doesn't present good working parameters if it works at low power.
Note that in this configuration the transmitter cannot work absolutely for long periods with
output power in antenna less than 8KW because the value of thermal power dissipation will
be greater than maximum value admissible for tetrode anode.
The reflected power value too read on the driver meter is never minimum when the
transmitter doesn't work at maximum output power for which is been setted.
2.3 TUBE
This power amplifier uses mainly the 4CX20000C tube.
The 4CX20000C ia a ceramic/metal power tetrode intended for use as a VHF power
amplifier. It features a type of internal mechanical structure which results in high RF
operating efficiency. Low RF losses in this
structure permit operation at full ratings to 110MHz.
The 4CX20000C provides high gain in FM broadcast service, and is also recommended for
RF linear power amplifier service. The anode is rated for 20Kw of dissipation with forced-
air cooling and incorporates a highly efficient cooler of new design.
It is also recommended for use as a grounded grid FM amplifier. In addition, grounded-grid
operation is attractive since a power gain as high as twenty times can be obtained.
2.4 R.F. CAVITY
The R.F. Cavity is accessible when are been removed the fixed screws of the front panel.
It's divide in three sections: the top section in which is placed the motorizzations of the
tunings; the central section in which is fixed the tube and the bottom section in which is
placed the tube socket.
A temperature probe is placed externaly on the air chimney that is placed on the top of the
R.F. cavity. The protection circuit that continuously monitors this probe, switch of the
amplifier in case of overtemperature.
This section of the chamber is mounted on four motorized bars and can go up and down in
according to desired transmission frequency.
In the central section of the chamber, around the tube's socket, is situated a collar with
fingers to ground the control grid.