R.V.R. Elettronica PJ250-NV User manual

Manufactured by R.V.R. Elettronica - Italy
TECHNICAL AND MAINTENANCE MANUAL
MANUALE TECNICO E DI MANUTENZIONE
PJ250-NV

PJ250-NV Technical and Maintenance Manual
R.V.R. Elettronica S.r.l. (Bo) Pag. 2
PJ250-NV
250W F.M. BROADBAD AMPLIFIER
Technical and Maintenance Manual
Manuale Tecnico e di
Manutenzione
English Pag. 3
Italiano Pag. 35

PJ250-NV Technical and Maintenance Manual
R.V.R. Elettronica S.r.l. (Bo) Pag. 3
INDEX
Prliminary Instructions & Warranty Information Pag. 5
Safety Regulations Pag. 7
SECTION 1
General Description Pag. 10
Electrical Specifications (Table A) Pag. 12
Dimensional & Environmental Specifications (Table B) Pag. 13
SECTION 2
Electrical Description Pag. 14
Front Panel's View Description Pag. 16
Front Panel's View (Fig. 1) Pag. 17
Rear Panel's View Description Pag. 18
Rear Panel's View (Fig. 2) Pag. 19
Top's View Description Pag. 20
Top's View (Photo 1) Pag. 21
Down's View Description Pag. 22
Upper's View (Photo 2) Pag. 23
Block Diagram (Fig. 3) Pag. 24
Recommend Test Equipment (Table C) Pag. 25
SECTION 3
Installation Procedures Pag. 26
SECTION 4
Maintenance Procedures Pag. 28
SECTION 5
Calibration Procedure of Modules Pag. 31
APPENDIX A
Circuit Diagram, Bills of Material and Layouts Pag. 67
Wiring Diagrams Pag. 68
R.F. Power Amplifier Card Pag. 69
Low Pass Filter Pag. 74
Transformer Supply Section Pag. 78

PJ250-NV Technical and Maintenance Manual
R.V.R. Elettronica S.r.l. (Bo) Pag. 4
Switching Power Supply Pag. 81
Directional Coupler Card Pag. 85
Alarms Card Pag. 89

PJ250-NV Technical and Maintenance Manual
R.V.R. Elettronica S.r.l. (Bo) Pag. 5
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:
1) Re-shipment of the unit to R.V.R. for repair purposes
2) Any unauthorized repair/modification
3) Incidental/consequential damages as a result of any defect
4) Nominal non-incidental defects
5) 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.
The warranty for a period of 12 months is referred to any R.V.R. product,
while for products as transistors, Mos-Fet and tubes of the final stages
is applied the man fact re's arrant of these de ices

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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),
until 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.r.l. - Broadcasting Equipment -
Via del Fonditore, 2/2c
Zona Roveri
40138 Bologna - Italy
Telephone [phone]
Fax [phone]
R.V.R. reserves the right to modify the design and specifications of the
equipment in this manual without previous notice.

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R.V.R. Elettronica S.r.l. (Bo) Pag. 7
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.r.l. 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

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R.V.R. Elettronica S.r.l. (Bo) Pag. 8
Treatment 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
IF UNCONSCIOUS, IF NOT BREATHING,
OPEN AIRWAY BEGIN ARTIFICIAL
BREATHING
LIFT UP NECK, TILT HEAD,
PUSH FOREHEAD BACK, PINCH NOSTRILS,
CLEAR OUT MOUTH IF NECESSARY, MAKE AIRTIGHT SEAL,
OBSERVE FOR BREATHING. 4 QUICK FULL BREATHS.
REMEMBER MOUTH TO MOUTH
RESUSCITATION MUST BE
COMMENCED AS SOON AS
POSSIBLE.
C CIRCULATION
CHECK CAROTID PULSE DEPRESS STERNUM 1 1/2" TO 2"
IF PULSE ABSENT, APPROX. 80 SEC. : ONE RESCUER, 15 COMPRESSIONS,
BEGIN ARTIFICIAL 2 QUICK BREATHS.
CIRCULATION
APPROX. 60 SEC. : TWO RESCUERS, 5 COMPRESSIONS,
1 BREATH
NOTE: DO NOT INTERRUPT RHYTHM OF COMPRESSIONS
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).

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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.

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R.V.R. Elettronica S.r.l. (Bo) Pag. 10
CHAPTER1
GENERAL DESCRIPTION
1.1 EXTERNAL DESCRIPTION
The PJ250-NV is housed in a 3U 19" rack.
On the front panel the alarm indicators are placed in a central position,
the mains switch and the meter for the forward and reflected power.
On the rear panel the R.F. Input and R.F. Output connectors are located,
together with the interlock connectors, one of BNC type and one VDE
female, the main voltage input.
1.2 ELECTRICAL DESCRIPTION
The PJ250-NV is a power amplifier working on the 87.5-108 band with
an output power in excess of 250W and a drive level of about 20W.
This amplifier uses a RF module composed of four amplification stages
(MRF317 or SD1480), with a switching power supplies fixed with the RF
module on cooling ribs to obtain a high dissipation.
A built in low pass filter suppresses the harmonic contents below the
FCC and CCIR requirements.
A protection system protects the amplifier against thermal problems,
excessive input drive power and excessive SWR inside the amplifier or
along the feeder.
This system provides an automatic reset to initial conditions when the
problem ceases.
1.3 METERS AND INDICATORS
The forward and reflected power of the amplifier are read by the
analog multimeter (5 Fig.1) and selected by the selector (6 Fig.1) on
the front panel.
Various led (3 Fig.1) indicators indicate the alarm conditions caused
by thermal problems, excessive input drive power (4.Fig.1) and excessive
SWR.
A green indicator confirms the amplifier is operational (7 Fig.1).
1.4 PROTECTION CIRCUITS
The protection circuits put the amplifier in stand-by in the case
of a fault condition.
After 90 seconds the protection reactivates the amplifier if the fault
has disappeared.
If not, this process is repeated 4 times, at the end of which the amplifier
stays disabled for 15 min.; after 15 min, if the trouble persists, the
protection performs other four cycles and then disables the amplifier
indefinitely.

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If during these cycles the anomaly disappears and the amplifier works
regularly for more than 15 min. the counting system is reset and the
original conditions established.
The protection acts for excessive SWR, over-temperature and overdrive.
It indicates the problem with warning lights and disables the pilot
exciter.
NOTE: The intervals described are nominal.
1.5 R.F. AMPLIFIERS
The amplifier comprises an RF broadband module with 50 Ohm input/
output impedance ("N" type connectors).
The output power of the module is approximately 250W across the frequency
range while the drive power is 20W; this output power is limited to 250W
to maintain a good level of reliability.
1.6 DEVICE SPECIFICATIONS
Refer to Table (A) for electrical specifications, and to Table (B)
for dimensional and environmental specifications.

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R.V.R. Elettronica S.r.l. (Bo) Pag. 12
TABLEA
ELECTRICAL SPECIFICATIONS
Power Supply 100-130V, 50-60Hz
198-250V, 50-60Hz
Cooling Forced ventilation
Frequency Range from 87.5 to 108 MHz
(other frequencies on request)
Power Output Max. 300W, Typ. 250 W
R.F. Drive Power approx. 20 W for Pout=250W
R.F. Input Impedance 50 Ohm
R.F. Input Connector Standard "N" type
R.F. Output Impedance 50 Ohm
R.F. Output Connector Standard "N" type
Harmonic and Spurious Suppression meets or exceed FCC and CCIR
requirements
Power Consumption 570 W

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TABLEB
MECHANICAL SPECIFICATIONS
Cabinet dimensions 439.00 mm (17.28") W
129.00 mm (5.080") H
341.50 mm (13.44") D
Panel dimensions 483.00 mm (19.00") W
132.50 mm (5.170") H
Operating temperature from -10°C to 50°C
Humidity 95% max., non-condensing
Weight 20.5 Kg

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CHAPTER2
ELECTRICAL DESCRIPTION
This section describes the overall working theory of PJ250-NV.
For ease of description the amplifier is subdivided into subassemblies
that will be discussed in detail below.
The block diagram is illustrated in Fig.3.
2.1 POWER SUPPLY
The power supply comprises two switching power supply (2-3 Photo
2) fitted to the cooling fins and its accessibles from the lower part
of the amplifier.
A mains transformer (2 Photo 1 and 1 Photo 1) has a selectable input for
voltages between 110 and 240 Volt and two outputs: A 31 Volt, B 18 Volt.
The output "A" drives the two switching units that generate the 28 Volt
needed by the R.F. modules.
Output "B" supplies the ALARMS CARD; inside this circuit a rectifying
and stabilization circuit provides the +15 Volt needed by the
electronics.
2.2 ALARMS CARD
This module (1 Photo 1) is composed of a board shielded by a metal
box mounted on the left side near the rear panel.
On this board, the electronics detect any system anomaly such as excessive
SWR, internal or antenna, over-temperature or over-drive.
This module will also, whenever possible, reset the system to its original
conditions, after a fault has occurred.
2.3 R.F. POWER AMPLIFIER
The module (3 Photo 1) is placed in the upper right side of the
amplifier. This module is totally shielded and placed on a heat sink.
This circuit delivers 300W with 25-30W of drive and is supplied by a
dedicated power supply.
The quiescent parameters of each module are:
VDC=28V Ia=15A Pout=250 W
The active devices employed are BJT NPN (MRF317 or SD1480).
2.4 LOW PASS FILTER
This filter (4 Photo 1) is fitted in a metallic box mounted on the
heat sink on the right position.

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Thanks to this low pass filter the harmonic suppression is more than
75 dBm.
2.5 DIRECTIONAL COUPLER
This circuit (5 Photo 1) is placed on the upper right side of the
amplifier and fitted on the rear panel.
This module makes the measurement of the forward and reflected power.
A BNC connector situated on the rear panel provides a power signal at
-40dB of the amplifier output power.

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FRONT PANEL VIEW DESCRIPTION
(FIG. 1)
1 Power On/Off Switch
2 Line A.C. Line Indicator
3 Alarms Leds indicating the PJ250-NV's alarms status
4 Grid Air duct grid
5 Meter Analog meter used to monitor the operating
parameters of the amplifier
6 Meter Selector Selector to monitor parameters:
FWD PWR Forward Power
RFL PWR Reflected Power
7 On "Power On" Indicator

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FIG.1

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REAR PANEL VIEW DESCRIPTION
(FIG. 2)
1 Fan Forced Ventilation
2 R.F. Input R.F. Input Connector ("N" type)
3 D.C. Fuse 1-2 Protection Fuse for R.F. Module
4 A.C. Line for Exciter A.C. Power Line for Exciter
5 Mains Voltage A.C. Power Line for Amplifier
6 Voltage Changer and Fuse block and line voltage selector. Use a
A.C. Line Fuse small screwdriver to change the fuse or the
line voltage. Rotate the block and position it
for the desired voltage.
7 R.F. Output R.F. Output Connector ("N" type)
8 R.F. Test -40dB -40dB with respect to the Output Level
9 Alamrs/Interlock BNC connector which permits the exciter to be
put in stand-by, in case of the amplifier
fault or in case of Ext.St.By.

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FIG.2

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TOP VIEW DESCRIPTION (PHOTO 1)
1 .................... Alarms Card
2 .................... Transformer
3 .................... R.F. Power Amplifier
4 .................... Low Pass Filter
5 .................... Directional Coupler