PROBLEM TROUBLESHOOTING GUIDE .............................................................................21
7.0
BILL OF MATERIALS,SCHEMATICS, AND PCBOVERLAYS ................................................22
Agile Logic Board Bill of Materials.......................................................................................22
Agile Output Amplifier Bill of Materials................................................................................26
Agile Up converter Bill of Materials.....................................................................................28
750 MHz Down Converter Bill of Materials .........................................................................33
Power Supply Bill of Materials.............................................................................................38
Tuner Processor Board Bill of Materials..............................................................................41
P-379 Processor
2
1.0SAFEGUARDS
General Safeguards
This section is written as a general guide for those having previous knowledge and experience
with these kinds of equipment. It is not intended to contain a complete statement of all safety
precautions, which should be observed by personnel using this or other electronic equipment.
To reduce the risk of fire or electric shock, do not expose this equipment to rain or moisture. Do
not open the cabinet. Refer servicing to qualified personnel.
1. READ INSTRUCTIONS - All safety, installation, and operating instructions should be read
before the equipment is operated.
2. RETAIN INSTRUCTIONS - The safety and operating instructions should be retained for
future reference.
3. FOLLOW INSTRUCTIONS - All safety, installation, and operating instructions should be
followed.
4. GROUNDING AND POLARIZATION - The P-379 Processor is equipped with a three prong
grounded power plug. Do not remove the ground prong from the plug. Do not use an AC
receptacle where the plug blades cannot be fully inserted.
5. SERVICING - Do not attempt to service this equipment yourself as opening or removing
covers may expose you to dangerous voltage or other hazards and will void the warranty.
Refer all servicing to qualified service personnel.
6. DAMAGE REQUIRING SERVICE - Unplug this equipment and refer servicing to qualified
service personnel under the following conditions:
• If the power cord or plug is damaged.
• If liquid has been spilled or objects have fallen into the equipment.
• If the equipment has been exposed to rain or water.
• If the equipment does not operate normally by following the operating instructions.
Adjust only those controls covered by the operating instructions. An improper
adjustment may result in damage and will often require extensive work by a qualified
technician to restore the equipment to its normal operation.
• If the equipment has been dropped or the cabinet has been damaged.
• If the equipment exhibits a distinct change in performance.
P-379 Processor
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Safety and First Aid
Personnel engaged in the installation, operation, maintenance, or servicing of electronic
equipment are exposed to the hazard of high voltage. It is imperative that all safety regulations
and precautions are consistently observed. Knowledge of first aid procedures is recommended.
The following information is presented as a reference only.
DANGEROUS VOLTAGES AND CURRENTS MAY BE PRESENT
IN THE EQUIPMENT EVEN THOUGH THE POWER IS OFF.
REFER SERVICING TO QUALIFIED PERSONEL
• At all times, avoid placing any part of the body in series between ground and circuit points,
whether power is on or off.
• It is the duty of all personnel to be prepared to give adequate emergency first aid treatment
and thereby prevent avoidable loss of life.
• There are three principle degrees of burns, recognizable as follows:
• A first-degree burn reddens the skin.
• A second-degree burn blisters the skin.
• A third degree burn chars the flesh and frequently places the victim in a state of shock
accompanied by respiratory paralysis.
• Respiratory paralysis can cause death by suffocation within seconds. It is imperative that
the approved methods of artificial respiration are initiated immediately and continue until the
victim’s breathing is normal.
• A muscular spasm of unconsciousness may render the victim unable to break free of the
electric power. If this is the case, turn the power off immediately.
DO NOT TOUCH THE VICTIM OR YOU MAY SHARE THE SAME
PREDICAMENT.
• If the power cannot be turned off immediately, very carefully loop a dry rope, article of
clothing, length of strong cloth or a rolled-up newspaper around the victim and pull the victim
free of the power source. Carefully avoid touching the victim or clothing.
• Once free of the power source, the victim must be placed in a reclining position and covered
with a blanket or newspapers to keep warm. At the first opportunity, enlist help in
summoning a doctor. If a doctor cannot be summoned, transport the victim to the doctor or
a hospital. Be sure the victim is kept well covered and warm while awaiting professional
treatment.
P-379 Processor
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2.0WARRANTY
Technalogix Ltd. products have been completely tested and found to meet specifications
and be in proper operating condition. They are warranted to be free from defects in
materials and workmanship for a period of one year from the date of shipment.
Technalogix Ltd. will not be liable for damages of whatever nature arising out of or in
connection with the equipment or its use thereof. Technalogix does not assume
responsibility for injury or damage resulting from the practices of untrained or unqualified
personnel in the handling of this equipment.
Technalogix Ltd. warranty does not include:
• Misuse, neglect or accident.
• Incorrect wiring and /or improper installation.
• Unauthorized repairs, modifications or use in violation of instructions issued by
Technalogix.
• Incidental or consequential damages as a result of any defect.
• Reshipment cost or insurance of the unit or replacement units or parts.
• Acts of God.
Technalogix agrees, at our option, to remedy warranted defects or furnish a new part in
exchange for any part of a unit which, under normal installation, use and service,
becomes defective. The user will pay for transportation costs to and from the repair
center.
To claim your rights under this warranty:
• Contact Technalogix and describe the problem in as much detail as possible. See
troubleshooting section in this manual. If a solution cannot be found at this time, it
may be determined that the unit will have to be returned to Technalogix for repair.
• Package equipment carefully for prepaid shipment to Technalogix. Include a written
description of the problem experienced and a copy of the original invoice establishing
warranty status.
Technalogix reserves the right to make revisions in current production of the equipment
and assumes no obligation to incorporate these changes in earlier models.
P-379 Processor
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3.0DESCRIPTION AND SPECIFICATIONS
General Description
The P-379 contains the latest in television electronics, including synthesized crystalreferenced phase-locked-loop oscillators, microprocessor control, saw-filtered if and
hybrid amplifiers. In addition to these features, the U.S. version contains automatic input
offset programming to remove input offsets inherent to off-air channels (0, ±10KHz),
cable standard channels (0, +12.5KHz, +25KHz) and Cable HRC channels (0.3KHz
master oscillator offset).
Standard Features
• Totally Microprocessor Controlled with Self-Diagnostic Monitoring
• Selectable Input Channels
• Off-Air Channels: 2 through 83 (VHF & UHF)
• Cable Standard Channels: 2 through 181 (54MHz through 1.2GHz)
• Cable HRC Channels: 1 through 181 (54MHz through 1.2GHz)
• Selectable Output Channels
• Cable Standard Channels: T7 through 118 (7MHz through 750MHz)
• Cable HRC Channels: 1 through 181
• Selected Using Internal Switch
• Automatic Input Offset Control
• Detects and Corrects Input Signal Offset Frequency for Heterodyne Processing
before the IF
• SAW-filtered IF - Designed for Adjacent Channel Operation
• +60dBmV Output Using Low-Distortion Hybrid Amplifiers
• Non-volatile Channel Memory
• Synthesized Oscillators
• Crystal Referenced
• Phase Locked
• Digital LED Readout
• RF Muted During Tuning
• Surface Mount Technology (SMT) Construction
Available Options
• “T” Input Channels
• Dual RS232 Control for Daisy Chain Capability
• Defeat able AGC for Manual Gain Control (MGC)
P-379 Processor
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HRC Output Frequency Set:
This Technalogix frequency agile product can be set for HRC frequency output. This
feature is controlled by an internal dip switch assembly, DS-1. The switch is located near
the right front corner (with the panel facing you) between the test point and the output
converter module. DS-1 is clearly marked on the PCB. Switch #3 placed in the OFF
position switches the output frequency to HRC on all channels. The switch is normally
set to ON at the factory.
Specifications
RF Characteristics
Frequency range 7 to 750 MHz
Frequency Response (one channel) ±0.5 dB
Frequency Tolerance ± 1KHz
Frequency Stability ±250 Hz
RF Output Level +60 dBmV max
Output Impedance 50 Ohms, unbalanced
Harmonics > 60 dB below rated power
Predominant Intermodulation Distortion dBc = decibels below visual
All others< -60 dBc
Return Loss > 14 dB
Spurious Emissions < -60 dBc
P-379 Processor
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NTSC Video Characteristics
System M/N
Input: C3F Neg NTSC
Input impedance 75Ohms, unbalanced
Input frequencies 7 to 800 MHz
Off-air channels 54 to 890 MHz
RF bandwidth 6.0Mhz
Input AGC range -16 to +16 dBmV
Input AGC type Sync Tip Ref.
Recommended input 0-10 dBmV, +60 to +70 dBuV
Noise figure 9dB VHF, 10dB UHF
Adjacent channel rejection 60dB
Image rejection 60dB
Audio carrier adjustment range Flat Response to –10 from
Below the video carrier Input levels
IF Section
Video IF level
Audio IF Level
Return Loss > 14 dB
IF Frequency, Video Carrier 45.75 MHz
IF Frequency, Audio Carrier 41.25 MHz
Video Sound Spacing + 4.5 MHz
Vestigial side-band width 0.75 MHz
Return Loss > 14 dB
Second IF Frequency 945.75 MHz
+ 37 dBmV, +97 dBμV
+22 dBmV, +82 dBμV
Physical Characteristics
Power Requirements 100-130, 210-230 VAC, 50/60 Hz
Operating Temperature 0 - 50°C
Weight 12 lbs
Dimensions (Processor only) W-19", D-14 ", H 1.75”, 1U-high
P-379 Processor
8
Block Diagram
Pre-Amp IN
RF Loop
IF Carrier
Pre-Amp Out RF In
Up converter
Tuner PCB
Display and Control Board
RF Output
Down converter
Output
Amplifier
P-379 Processor
9
4.0INSTALLATION
This section contains installation recommendations, unpacking, inspection, and
installation instructions for the Technalogix P-379 Processor. Carefully read all material
in this section prior to installation. Also read and review operating procedures later in this
section.
Building Recommendations
The quality of the building is of great importance if you are to expect long life and
continued performance from the processor. The building must be clean, dry, temperature
controlled and secure. The processor takes up a single 1-U high space on a 19” rack.
Don’t forget to allow space in the building for any additional racks to house test
equipment, a workbench area, line regulating transformers, ladders, equipment and
parts storage, first aid kit, emergency generator if used, as well as heating and cooling
devices that may be unique to your installation. A sloping roof will tend to develop leaks
less rapidly. The building should be well roofed with good material. The cooling load will
be lowered with reflective or light colored roofing material.
Heating and Cooling Requirements
The environment’s temperature will contribute greatly to the length of the processor’s
life. Technalogix recommends that the building’s filtered air intake must have capacity for
all air-flow in the building plus an additional 20%. Keep the intake below the roofline to
avoid intake of solar heated air. Please ensure that the intake and exhaust areas are on
the same side of the building to avoid pressure differentials during windy conditions.
Also, do not position intake near exhaust’s preheated air. If air conditioning is required to
cool the shelter, discuss the situation with a qualified HVAC technician. Under average
conditions, 12,000 BTUs will cool approximately 500 square feet to a comfortable level.
P-379 Processor
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Electrical Service Recommendations
Technalogix recommends that a qualified, licensed local electrician be consulted for the
required electrical service. We suggest local electricians because:
• The personnel knows the local codes
• The personnel can be on site readily
• You are apt to get better overall support if you give what business you can to local
suppliers
Technalogix recommends that proper AC line conditioning and surge suppression be
provided on the primary AC input to the power amplifier. All electrical service should be
installed with your national electrical code in your area, any applicable provincial or state
codes, and good engineering practice. Special consideration should be given to lightning
protection of all systems in view of the vulnerability of most translator sites to lightening.
Lightning arrestors are recommended in the service entrance. Straight and short
grounds are recommended. The electrical serviced must be well grounded. Do not
connect the unit to an open delta primary power supply, as voltage fluctuations could
harm the unit. Branch your circuits. Do not allow your lights, your workbench plugs, and
your translating equipment off of one circuit breaker. Each translator should have its own
circuit breaker, so a failure in one does not shut off the whole installation.
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Antenna and Tower Recommendations
Your preliminary engineering workgroup should establish your antenna and tower
requirements, both for receiving and transmitting antennas. Construction of sturdy, high
quality antenna/tower systems will pay off in terms of coverage of your service area, the
overall quality and saleability of your radiated signal, and reduced maintenance
expenses. Technalogix provides complete turnkey antenna systems if needed. If your
site is serving as a translator, your receiving antenna should be line of sight to the
originating station, both winter and summer. The foliage will change with season.
Transmitting antennas can enhance or seriously impair the translator output. It is
assumed that one has been selected prior to system installation, but the best-designed
antenna system will function poorly if shortcuts and compromises are used during
installation. Follow the manufacturer’s instructions exactly, along with any engineering
data prepared for the site.
The selection, routing, and length of coaxial cable are extremely important in the
installation. If there is a 3 dB line loss in the cable between your unit’s output and the
transmitting antenna, a 500 watt unit will only deliver 250 watts to the antenna. Buy the
best cable you can obtain, route it via the shortest way to the antenna, and keep it
straight. Do not form it into sharp bends on its way. Do not use any more cable fittings
for the installation than absolutely necessary. All cautions here apply equally to all
coaxial cables in the system - input and output. The better known tower manufacturers
offer complete technical and safety documentation with their towers. Be sure that you
have this information as it regards wind loading, guying, etc. Be absolutely safe and
certain about this aspect as human lives may be at stake.
Shelter Security
The FCC requires that the translator be secure from entry or control by unauthorized
persons, and that any hazardous voltages or other dangers (including most tower bases)
be protected by locks or fences as necessary to protect personnel and prevent
unauthorized tampering or operation. Security of the building further implies that it be
secure from wildlife. Use sturdy construction materials, including sheet metal if
necessary. Holes around conduit, cable, and other similar entry points should be stuffed
with steel wool and caulked to prevent entry of wildlife. Other features of security for your
shelter may include its location with respect to the prevailing wind conditions. Location
leeward of some natural topographical feature will prevent wind damage and snowdrifts.
Check the soil runoff conditions that may slow or hasten wind or water erosion and other
concerns that may be unique to your location
.
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Unpacking and Inspection
Check the outside of the container. Carefully open the container and remove the
processor. Retain all packing material that can be reassembled in the event that the
equipment must be returned to the factory.
Exercise care in handling equipment during inspection to prevent
damage due to rough or careless handling.
Visually inspect the enclosure of the processor for damage that may have occurred
during shipment. Check for evidence of water damage, bent or warped chassis, loose
screws or nuts, or extraneous packing material in connectors. Inspect all connectors for
bent connector pins. If the equipment is damaged, a claim should be filed with the carrier
once the extent of the damage is assessed. Technalogix cannot stress too strongly the
importance of immediate careful inspection of the equipment and subsequent immediate
filing of the necessary claims against the carrier if necessary. If possible, inspect the
equipment in the presence of the delivery person. If the equipment is damaged, the
carrier is your first area of recourse. If the equipment is damaged and must be returned
to the factory, phone for a return authorization. Claims for loss or damage may not be
withheld from any payment to Technalogix, nor may any payment due be withheld
pending the outcome thereof. Technalogix cannot guarantee the carrier’s performance.
P-379 Processor
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Location and Function of Controls and Connectors
The following illustrations depict the location of the installation connectors when
installing the power amplifier with a processor.
FRONT
BACK
Aural Carrier Level - Allows user to set aural carrier level relative to visual carrier level.
Processor is factory tested at –10 dBc (decibels below visual carrier).
Input Source – Allows the user to select between cable HRC, cable standard or off-air.
Input Select – Allows the user to select the desire channel for input signal.
Output Select – Selects the desired channel of operation. If you require a lower channel
than the one currently displayed, push the toggle switch down. The channels will
change one at a time as many times as you press the switch. Holding the select switch
in the up or down position will “scan” to the desired channel. It is normal for the
frequency lock LED to turn off during and for a few seconds after, changing channels.
The switch must be held up or down initially for three seconds. This helps to ensure that
no accidental channel changes will occur.
Output Level – Sets visual carrier output level.
RF Out Test Point – Provides a sample of the RF output level which is 20 dB below the
actual value. RF test point is only a relative indicator of the actual RF output level and
may vary. All RF operating measurements should be made at the RF output of the unit.
RF Output - Modulated Audio/ Video output capable of +60 dBmV levels using built in
low distortion hybrid amplifiers.
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RS-232 Ports – Set up for optional RS-232 control option.
Combined IF Input/ Output – 45.75 MHz visual carrier and 41.25 MHz audio carrier
intermediate frequency signal loop.
RF In – Modulated RF input – Recommended RF input is 0 dBmV to 5 dBmV.
T-Channel Switch – Allows the user to switch the optional T-channel on or off. To use
the T-Channel Input Option, if the unit is so equipped, ensure that that a T-channel input
source is attached to the F-connector marked “T-Channel IN” on the rear panel. Position
the T-Channel switch on the rear panel of the P-379 to the “ON” position.
P-379 Processor
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5.0OPERATING PROCEDURE
Preliminary Hook-up
1. Position the Technalogix P-379 agile processor in its installation mount or rack.
2. Locate the antenna lead or cable drop that will provide the input signal for the P379 agile processor.
3. Ensure that the input signal provides an adequate signal. The recommended
input level for best performance from the Technalogix P-379 Processor is 0 to
+10dBmV (+60dBuV to +70dBuV).
Setup and Operation
1. Connect the input-source cable drop or antenna lead to the F connector
On the rear panel of the P-379 marked “RF INPUT”.
NOTE: If you have a P-379T, also connect the T- or return-channel input source
cable to the F-connector on the rear panel of the P-379 marked “T-INPUT”.
2. Connect the output of the P-379 to a 50 Ohms load via an RF cable connected to
the F-connector marked “RF OUTPUT” on the rear panel of the P-379.
3. Connect the Technalogix P-379 to a proper AC electrical source. The correct
electrical input type for the unit is marked on the rear panel, directly under the
entrance of the power cord into the unit.
Exercise care in handling equipment during inspection to prevent
Damage due to rough or careless handling.
Technalogix power supplies are designed so that, under certain power
line or heat buildup conditions, the unit shuts off. An indication is no RF
output, although the POWER LED on the front panel remains illuminated.
If this occurs, unplug the power cord and wait at least two (2) minutes
before reapplying power. Upon reapplying power, you should again have
RF output. If the unit fails to provide RF output again, or should the unit
return to shutdown mode, telephone your distributor for assistance or call
Technalogix direct at 403-347-5400. Remember: Technalogix
recommends a 1.75” air circulation space between each piece of rackmounted equipment.
P-379 Processor
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4. Input channel selection. Select the desired input source type and channel using
the front panel controls. Because the built-in input offset feature automatically
removes any input offset, no calculations or adjustments are required. The
Technalogix P-379 Agile Processor has a built-in delay in the input- and outputchannel tuning circuits. In order to change channels, hold the channel select
switch in the up- or down-position for at least three seconds. When the circuit is
defeated, channel selection will proceed normally. Channels can be changed
one at a time by raising/lowering the channel select switch one channel at a time;
or channels can be scanned rapidly by raising/lowering the channel select switch
and holding it while the unit rapidly moves through the channels. However, once
the channel select switch is released for more than one second, the delay-tuning
circuit reactivates.
Until an active input channel is selected, the input channel display will flash.
Once the input channel is selected, the input channel display will stop flashing as
long as the input signal level is within the required capture range. If the input
channel display continues to flash after a known, active input channel is selected,
check the level of the input signal to ensure it is at adequate levels for detection
(from –5dBmV to +10dBmV) and not too low or too high.
The FREQUENCY LOCK LED on the front panel display may also blink during
input-channel tuning. This is because, when the unit is being tuned, an RFoutput muting circuit is enabled to ensure that moving RF carriers do not interfere
with any existing channels on the cable system.
T-Channel Input Option. To use the T-Channel Input Option, if the unit is so
equipped, ensure that that a T-channel input source is attached to the Fconnector marked “T-Channel IN” on the rear panel. Position the T-Channel
switch on the rear panel of the P-379 to the “ON” position.
If your P-379 has green LED’s on the front panel, above the channel select
switch, the LED marked “T-channel” will illuminate when a channel in that range
is selected. If your P-379 does not have green LED’s, but does have a threenumber channel display, the selected T-channel will be indicated by a “-“ (minus)
sign preceding the number of the T-channel selected. When in T-channel
operation, only the T-channels will be selected.
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5. Select the desired output channel. Unless otherwise specified, the unit is factory
set for cable standard channel frequencies and the microprocessor automatically
selects the proper FCC offset for the output channels, requiring no calculations or
adjustments.
NOTE: For HRC output channels, see the section in this manual entitled
HRC Output Frequency Set.
During output-channel tuning, the FREQUENCY LOCK LED on the front panel
display may also blink during input-channel tuning. This is because, when the
unit is being tuned, an RF-output muting circuit is enabled to ensure that moving
RF carriers do not interfere with any existing channels on the cable system.
6. Connect a spectrum analyzer (recommended) or a field strength meter to the Fconnector marked “RF OUTPUT” on the rear panel of the P-379 agile processor.
If the unit is already connected to another device, disconnect that device from the
unit.
7. using the front panel control marked “OUTPUT LEVEL,” adjust the RF output of
the unit. The recommended output level is between +55dBmV and +60dBmV
(+115dBuV and +120dBuV).
Setting the RF output level below +55dBmV may adversely affect the parameters
of the modulating signal; setting the RF output level above +60dBmV will
adversely affect the quality of performance of the P-379. Ensure that the RF
output level is checked each time an output channel is selected, particularly
when the selected channel is a return or “T” channel or when the channel
selected is in a different band from the previous channel.
NOTE: Ensure that you do not overdrive the power amplifier. Please see
the power amplifier manual for recommended levels.
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8. While the RF OUTPUT signal is still connected to the spectrum analyzer or field
strength meter, observe the aural carrier level. The difference between the video
carrier level and the audio carrier level – the “Delta AV” or ΔAV – should be the
same as the input source. In other words, if the RF INPUT signal ΔAV is 13dB,
the RF OUTPUT signal ΔAV should be 13dB ±2dB. Minor adjustment of this
ΔAV may be made either at the input signal source (if the input signal is not from
an off-air source) or with the AURAL CARRIER LEVEL control on the front panel
of the P-379. When switching to either of the frequency sources (STD or HRC),
the internal aural carrier attenuator drops automatically from 6dB to 0dB since
the ΔAV for cable signals has normally been preset at the headend. However,
the ΔAV for off-air signals may vary considerably. Normal operation level of the
aural carrier is 10 to 13dB below the video carrier. If adjustment of the AURAL
CARRIER LEVEL control on the front panel of the P-379 will not bring the ΔAV of
an off-air signal into an acceptable range, check the ΔAV of the input signal. If
the ΔAV of the input signal is too small or is negative (the aural carrier is above
the video carrier), it is possible that the AURAL CARRIER LEVEL control of the
P-379 will be unable to compensate. Check the input signal before contacting
Technalogix for return-for-repair information.
P-379 Processor
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Translator Hookup
1. Connect modulated video from P-379 RF OUT to the Technalogix power amplifier.
2. Turn down RF level on P-379 all the way.
3. Ensure that IF OUT is connected to IF IN on the P-379 processor using the loop F to
F cable supplied.
4. Connect the transmitting antenna cable to the RF output connector on the power
amplifier. It is recommended that a quality through line wattmeter be installed in this
same line.
5. Verify that all signal and RF cables are connected properly.
6. After following proper installation procedures outlined in the power amplifier manual,
plug the power amplifier’s power cords into an appropriate electrical outlet.
Output power should be adjusted with a sync and blanking signal only with the aural
carrier removed. This is simply done by disconnecting one end of the audio carrier loop
found on the back panel of the P-379.
AUTOMATIC MORSE CODE KEYING DEVICE
Translators must be equipped with a device that identifies the call signal of the translator
in Morse code (usually be frequency shifting the aural carrier not less than 5 kHz or
amplitude modulating the aural carrier with a 200 Hertz tone) once each hour. This
feature can be disabled if the parent station for the translator sends the call sign of the
translator in the visual picture or identifies it as part of the aural modulation. The end
user must do this as a regulation of FCC.
P-379 Processor
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6.0PROBLEM TROUBLESHOOTING GUIDE
The guide below covers some typical symptoms, possible associated causes and
suggested actions to follow before returning the unit for repair. It is not meant to be allinclusive.
Symptom Possible Cause Suggested Action
No output
Weak output
Unit tuned to input channel in
Input signal is too weak Ensure input signal strength is
IF loop cable on rear of unit
Unit not plugged in or not
Excessive noise
Spurious signals
IF level too high (most often
Input signal too strong or no
Bad/noisy video Aural carrier interfering with
Channels do not change Delay feature active Hold channel change switch in
Unit tuned to output channel
different from desired (this
occurs particularly on the units
which have green LED on the
front panel to indicate “T”
channels and channels above
99)
a different range than desired
loose/disconnected
getting power
Output level above rated
maximum (most often occurs
when changing from highnumber channel to lownumber channel, especially to
the “T” channels)
occurs when routing IF
through scrambler or other
external device)
input signal at all
video carrier
Ensure selected output
channel is desired channel
Check INPUT SOURCE
SELECT switch for proper
source selection
within specified range
Check IF loop cable is
securely attached
Check power cord and power
source, fuse
Measure RF output from rear
panel jack and adjust front
panel OUTPUT LEVEL control
as required
Measure normal IF output
level for applied CW
/unmodulated input carrier and
ensure same level is returned
to unit after external
processing
Measure input RF level and
pad to within specified input
levels; if signal not present,
change to active channel
Measure Aural Carrier level
and/or adjust AURAL
CARRIER LEVEL control on
front panel
raised/lowered position for at
least three seconds