You’ve already unpacked it, haven’t you? You’ve unpacked
it and plugged it in and turned it on and fiddled with the
knobs. No? Okay, good. Please take a few minutes to read
the manual and familiarize yourself with your new
Technalogix power amplifier.
We believe that this manual, and of course our equipment,
should be everything you need to get on the air with superb
broadcast quality video. We understand that a capable and
confident user will get the most out of our product and we
have made every attempt to educate readers of all technical
levels. If there is something that is not clear, or you require
further information, please do not hesitate to contact us and
we’ll be glad to help out.
Technalogix Ltd.
#4, 8021 Edgar Industrial Place
Red Deer, Alberta, Canada
T4P 3R3
Phone: 403.347.5400
Fax: 403.347.7444
URL: www.technalogix.ca
Email: technical@technalogix.ca
sales@technalogix.ca
We truly appreciate that you have chosen us as your
television broadcast system supplier. Happy viewing.
This section is written as a general guide to keep all 5 fingers on your hand and is intended 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.
DOCUMENTATION - Read, retain and follow instructions before operating the equipment.
There is a lot of useful information in the manual, and besides, we spent a lot of time
writing it!
ENVIRONMENT - To reduce the risk of fire or electric shock, do not expose this
equipment to rain, moisture, or rye and sodas at the company Christmas party. Refer all
servicing to qualified service personnel.
SERVICING - Do not attempt to service this equipment yourself as opening or removing
covers can result in a warm tingly feeling and will void the warranty. Refer all servicing to
qualified service personnel.
Technalogix Ltd TAVD-500 Transmitter
I-1
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.
• At all times, avoid placing any part of the body in series between ground and circuit points,
whether power is on or off.
• Dangerous voltage may be present in equipment even though power is off. Do not open the
cabinet. Refer servicing to qualified service personnel.
•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.
Technalogix Ltd TAVD-500 Transmitter
I-2
Operating Safeguards
It is a known fact that our broadcast transmitters and translators enjoy 50-ohm load
impedances. So much so, that it is imperative you maintain 50-ohm impedances throughout
your system. In return, your equipment will provide you with maximum power transfer to the
antenna and decreased reflected power heading back towards the amplifier pallets, reducing
the amount of magic smoke that gets let out of the power amplifier. Before anything is turned
on, ensure that there is a 50-ohm path from the output of each stage to the input of the next, all
the way to the antenna.
In addition to maintaining proper 50-ohm impedances throughout the signal chain, it is also
important, whenever possible, to make sure the RF drive going to the input of the power
amplifier is removed before turning on or turning off the DC power supply. This is because all of
the RF transistors used in the individual amplifier pallets are fabricated with LDMOS (Laterally
Diffused Metal Oxide Semiconductor) technology. Nice and linear yes, but they do not like to
make any RF power when their supply voltages are not within a specific range. When you first
turn your power amplifier on or off, the DC power supply’s output voltage may take a while to
stable out to a safe operating voltage. Ten seconds wait before applying the RF drive will
ensure no issues arise.
Our power amplifiers are designed to reliably generate a specific RF output power. Failing to
adhere to overdriven amplifier warnings can decrease the reliability of your system, and frankly,
makes our repair department busy and grumpy. If you need to transmit to a little larger
coverage, you are better off increasing antenna gain, and more importantly, antenna height
above average terrain. On TV and FM broadcast frequencies, insufficient antenna height puts
an upper limit on your range, regardless of power levels, as the distance from your antenna to
the radio horizon is limited.
Technalogix Ltd TAVD-500 Transmitter
I-3
Section II - Warranty
Our legalese is straightforward. It is simply designed to give you peace of mind and helps you resist
the temptation to have your electronics friend try to repair your Technalogix product.
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. If the system becomes damaged in
shipment and there are obvious signs of damage to the outside of the packaging, notify your courier
immediately before that courier walks out the door.
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 nature or terrorism.
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. If you require technical service on the
site, the cost to you will be $800.00 US per day plus air fare and meals.
Technalogix Ltd TAVD-500 Transmitter
II-1
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, once a Return
Materials Authorization (RMA) number is provided. Please look under our web site
(www.technalogix.ca
•Package equipment carefully for prepaid shipment to Technalogix. Include a written description
of the problem experienced, a copy of the original invoice establishing warranty status, and the
RMA.
Technalogix reserves the right to make revisions in current production of the equipment and
assumes no obligation to incorporate these changes in earlier models.
Shipping Address:
Technalogix Ltd.
ATTN: RMA#
#4, 8021 Edgar Industrial Place
Red Deer, Alberta, Canada
T4P 3R3
Ph: 403.347.5400
Made in Canada, returned for repairs
) for the RMA form (Service) and fill it out. Either fax it to us or email to us.
Technalogix Ltd TAVD-500 Transmitter
II-2
Terms & Conditions of Sale
Sales by Technalogix Ltd (“Seller”) are made only on the terms which are contained in this
Terms and Conditions of Sale Policy. Seller hereby gives notice of its objection to any different
or additional terms and conditions. All sales are expressly conditional upon Buyers’ assent to
the terms and conditions set forth below. These terms and conditions may be modified or
supplemented only by a written document sighed by the authorized representative of Seller.
These terms and conditions supersede any prior and/or contemporaneous agreements or
correspondence between Buyer and Seller. Any order received and accepted by Technalogix
Ltd (Seller) shall be construed as an acceptance of Seller’s offer to sell its products to the
purchaser (Buyer) in accordance with the terms and conditions of sale set forth herein. No
waiver, whether express or implied, by Seller of any of the terms or conditions hereof shall be
deemed a continuing waiver or trade custom between the parties, but shall apply solely to the
instance to which the waiver is directed.
Ordering Information
All orders must be in writing and/or accompanied by a PO. 50% down payment is required with
all orders. No orders are considered an order until the down payment has been paid.
Order Confirmation
A purchase order is not binding on Seller until Buyer has received Seller’s order confirmation or
acknowledgement.
Pricing Policy
Prices for products do not include taxes or any additional charges. All prices are FOB shipping
point and prices do not include freight/handling charges and insurance charges. All prices are
in U.S. currency.
All prices published or quoted by Seller may be changed at any time without notice. Unless
otherwise specified, written quotations expire thirty (30) days from the date issued and are
subject to change or termination by notice during this period.
Taxes
Prices for all products do not include any sales, use, excise or other taxes. Buyer agrees to pay
all applicable federal, state, and local taxes, duties and other fees on product and services
ordered. If Buyer claims an exemption form any tax, Buyer shall submit to Seller the
appropriate exemption certificates.
Shipping
Shipping is the responsibility of the Buyer. This includes all freight, custom and brokerage
charges and duties.
Technalogix Ltd TAVD-500 Transmitter
II-3
Terms of Payment
Seller will provide credit terms to Buyer at its discretion. Such terms are subject to change at all
times. If credit is provided, Seller will invoice Buyer on the date the product is ordered. Such
invoices will be due and payable net thirty (30) days from date of invoice, subject to credit
approval. If credit is not established or maintained, terms shall be net cash on or prior to the
Delivery Date. Seller reserves the right, at its sole discretion at any time to revoke any credit
previously extended.
Past due accounts shall be charged two percent (2%) per month, or the highest rate permitted
by Alberta law, whichever is less, and will be added to the outstanding balance. In the event
Buyer defaults on payment, Buyer shall be liable for all collection cost, including reasonable
attorney’s fees and costs.
Changes and Cancellation
Purchase orders that have been accepted by Seller may not be changed or cancelled, in whole
or in part, without written consent of Seller. All changes must be include in a change order
reflecting the purchase order number and submitted to the Seller. All other changes will not be
accepted or acknowledged. Changes may affect delivery dates. Expenses incurred because of
the changes shall be charged to the Buyer. Buyer will be liable for Seller’s costs incurred, plus
a reasonable profit, for the portion of the work terminated, in accordance with generally
accepted accounting principle, together with cancellation charges.
Orders for standard product may be changed by Buyer, with no penalty to the Buyer, provided
that Buyer provides Technalogix notification at least 30 days prior to the scheduled ship date.
Order changes received within 30 days of the scheduled ship date may be subject to an order
change charge; a schedule detailing these charges will be forwarded to Buyer when Buyer’s
change order is acknowledged. In no event can any aspect of the order be changed after
product shipment has occurred.
Orders for custom product may be canceled by Buyer, provided that Buyer pays Seller for
completed work allocated to Buyer’s order at the time of termination of the work at the unit
selling price and all costs, direct and indirect for work-in-progress as well as costs resulting from
cancellation and a reasonable profit therein. Specific cancellation charges will be dependent on
the type of custom product ordered; a schedule detailing these charges will be forwarded to
Buyer when Buyer’s cancellation is acknowledged. Orders for custom product are subject to a
cancellation fee of up to 100% of the order, depending on the stage of completion of the order
at the date the cancellation or revision is accepted.
Custom Products Policy
Custom items are not returnable; items other than “off the shelf” products are considered
custom. Custom products, by their nature, are products and materials which have been altered,
modified, cut, amended and customized to your order, and are not resalable or returnable.
Technalogix Ltd TAVD-500 Transmitter
II-4
Orders for custom product are subject to a cancellation fee of up to 100% of the order,
depending on the stage of completion of the order at the date the cancellation or revision is
accepted.
Returns
The return of Products without a written authorization by Seller will not be accepted. Returns
are accepted only with a valid Return Material Authorization (RMA) number for items to be
returned. To receive authorization for Product return, please call customer service. There is a
standard 25% restocking cost assessed on most returns.
All returned products must be unused, and in original condition. No refund or credit shall be
given for damaged products.
We do not accept return packages without a valid RMA number and we do not accept postagedue or C.O.D. packages at any time for any reason.
Excusable Delay
Seller shall not be liable for any loss or damage resulting from any delay in delivery or failure to
deliver which is due to any cause beyond Seller’s control, including, without limitation, acts of
nature, unavailability of supplies or sources of energy, riots, wars, fires, floods, epidemics,
lockouts, strikes and slowdowns, delays in delivery by supplies, or acts or omissions of the
Buyer. The Buyer shall be liable for stage charges, including but not limited to all third party
costs and expenses incurred by Seller, in holding or storing products for the Buyer or at the
Buyer’s request.
Assignment
Buyer shall not assign any duties nor assign any order or any interest therein without the written
consent of the Seller. Any such actual or attempted assignment shall entitle Seller to cancel the
order upon written notice to Buyer.
Installation
Seller assumes no obligation to install any product sold or to place any products in working
order at Buyer’s premises
Validity of Separate Clauses
If any provisions of this agreement shall be held invalid, illegal, or unenforceable, the validity,
legality or enforceability of the remaining provisions shall not be affected or impaired thereby.
• Front panel Liquid Crystal Display (LCD) to monitor forward and reflected RF power, and DC
voltage
• Microcontroller-based monitoring and control ensures amplifier will never be overdriven and
high VSWR will not damage amplifier
• AC circuit breaker on back panel to eliminate replacement of fuses
• All aluminium enclosure maintains power amplifier’s light weight
• Simple design using commonly available parts ensures reliable operation
Technalogix Ltd TAVD-500 Transmitter
III-1
Principle of Operation
The TAVD-500 power amplifier supplies a 500-watt (rms) 8VSB television signal on any of the VHF
television channels 2 through 13. Please note that channel selection must be made at time of
order, as the transmitter or translator is calibrated and tested to the channel requested and is not
field tuneable. The TAVD-500 power amplifier is a modular solid-state system comprised a TAVD500 500-watt broadcast amplifier utilizing readily available RF components wherever possible, thus
enhancing the serviceability of the equipment.
Each TAVD-500 is comprised of a VHFTV-25 and a VHFTV-200 driver pallet and (4) VHFTV-400
final pallets that are combined to create 500 watts (rms) 8VSB power. The amplifier modules are
stable for high reliability and long service life.
The TAVD-500 features ultra linear amplification and individual channel RF output bandpass
filtering.
The following block diagram illustrates the 500-watt system.
Technalogix Ltd TAVD-500 Transmitter
III-2
FILTER
TAVD -50 0 AM PL IFI ER
Modulator or
Processor
External
power
supply
RF Out
TAVD-500 BLOCK DIAGRAM
Date: May 21, 2009 Page: 1 of 1
Rev ID
TAVD-500 Block Diagram
The RF signal enters through the RF Input connector on the power amplifier enclosure from the
modulator or processor. It then passes through an RF attenuator to limit the output power level
of the power amplifier and to help buffer any transients that may come into the power amplifier.
After attenuation, the signal gets preamplified through the two driver pallets before the signal
gets split into (4) signals for final amplification. The output of the (4) final amplifier pallets get
combined and passes through an isolator. Finally, the signal passes through a dual directional
coupler for monitoring purposes before heading out to the combiner/filter enclosure and then
through to the antenna.
Technalogix Ltd TAVD-500 Transmitter
III-4
VHFTV-200 Driver
Pallet
VHFTV-25 Driver
Pallet
A=-0.05 dB typical
A=-0.5dB t ypi cal
To W attmete r
and Ant en n a
VHFTV-40 0H FINAL
AMPLIFI ER PAL LET
VHFTV-40 0H FINAL
AMPLIFI ER PAL LET
4 WAY SPL IIT ER
4 WAY COM BIN ER
RF INPUTRF OUT
Directional C
TERMINATION
50 OHM
ATTENUATION
TAVD-500 Power Amplifier Block Diagram
Date: May 21, 2009Page: 1 of 1
Rev ID
Specifications
Electrical specifications that are specific to the unit are included with the shipment in addition to
being kept on file at Technalogix.
Physical Characteristics
Power Requirements
Power Supply
Operating Temperature
220 VAC, 11 A
0 - 50°C
Dimensions
TAVD-500 Power Amplifier
Filter
Power Supply
W-19" flange (17” encl.), D-25-
W-19" flange (17” encl.), D-25-
W-19" flange (17” encl.), D-25-
¼", H-101/2”
(6U)
¼", H-8-¾”
(5U)
¼", H-5-1/4”
(3U)
AC
Technalogix Ltd TAVD-500 Transmitter
III-6
Section IV – RF Components
Amplifier Pallets
The VHFTV-25 pallet is a two stage ultra linear class-A linear pallet. The VHFTV-25-L has a typical
gain of 36dB and the VHFTV-25-H has a typical gain of 34dB. These pallets draw no more than
3.5Adc total drain current (the exact bias and drain currents of your system are found in the spec
sheet supplied with each manual). The quiescent and drain currents can be measured on the
VHFTV-25 pallet by measuring the voltage drop across the current sense resistor found directly at
the DC power supply lead input to the pallet. This resistance is 0.01-ohms, providing a 10mV per
ampere ratio.
The VHFTV-200 pallet is a two stage ultra linear class-A linear pallet. The VHFTV-200-L and –H
pallets have a typical gain of 20dB and the VHFTV-200-H has a typical gain of 18dB. These pallets
draw no more than 4 Adc total drain current (the exact bias and drain currents of your system are
found in the spec sheet supplied with each manual).
The final amplifier stage is comprised of a VHFTV-400-L or VHFTV-400-H amplifier pallet and
are characterized with typical gains of 18 dB (low band) or 16dB (high band) and maximum
drain currents of 17 A (low and high band) for 8VSB systems.
Each of the amplifier pallets is connectorized. All amplifier pallets must have the transistor drain
voltages reach at least 26Vdc before the RF drive is applied.
Technalogix Ltd TAVD-500 Transmitter
IV-1
Filter
The passive bandpass filter rejects spurious and harmonic output products and passes the VHF
channel RF output. The cavity resonator uses aperture coupling and is a linear resonator design.
Typical insertion loss is 0.6 dB to 1.0 dB depending on channel frequency. Average roll off is –33
dBc at a point 4.5 MHz below the peak visual carrier frequency and –30 dBc 9.0 MHz above the
peak visual carrier frequency. The filter is DC grounded on both the input and output for additional
lightning protection.
Directional Coupler
The Technalogix dual directional couplers provide DC voltages proportional to forward and reflected
RF power monitoring. These analog voltages are converted for processing using analog-to-digital
converters and provide the control system with valuable data for monitoring purposes. Output
power should be set following the operating procedure found elsewhere in this manual. The
directional coupler has a typical insertion loss of 0.5dB and its Type N connectors can handle
1,500-watts peak while the 7/16” DIN connectors can handle over 3,000-watts peak.
Isolator
The power amplifier pallets are protected in part by the isolator located in the power amplifier
enclosures. It is actually made up of a circulator and 50-ohm dump resistor. The circulators’
specifications include an insertion loss of less than 0.2dB with an isolation rating better than 20dB.
Any reflected power gets dumped into the flanged power resistor. Even though the flanged power
resistor is rated for only 150-watts, and there could potentially be 500-watts being reflected back
into the circulator, the software will recognize quickly that reflected power is present and turn the
carrier off. This way, there is instantaneous protection due to the isolator setup and long term
protection due to the software.
Technalogix Ltd TAVD-500 Transmitter
IV-5
Section V – Power Supply
Switching AC-DC power supplies are used to power the amplifier pallets, the control circuits, and all
of the fans. The power supply is set at 30.0 Vdc nominally. All fans run off this same supply, though
they pass through a series dropping resistor to lower the supply voltage, as the fans are 24Vdc.
The (2) power supplies found in the power supply enclosure are Mean Well RSP-1500-27. The
switching power supplies are fully protected against short circuit and output overload. Short circuit
protection is a cycling type power limit. The internal AC fuse is designed to blow only on a
catastrophic failure in the unit – the fuse does not blow on overload or short circuit. The thermal
shutdown automatically recovers when the power supply chassis cools down.
AC (220Vac) is fed into the power supply enclosure via a filtered AC entry and then through a circuit
breaker.
AC input voltage range
DC adjustment range
Overload protection
Over voltage protection
Setup, rise, hold up time
Withstand voltage
Working temperature
Safety standards
EMC standards
Packing
90~264VAC; 127~370VDC
-30~+10% rated output voltage
105%~135% constant current limiting ,
shut off after 5 sec.
115%~140% rated output voltage
1500ms, 100ms, 10ms at ful l load and 230VAC
I/P-O/P:3KVAC, I/P-FG:1.5KVAC, 1 minute
-20~70OC (refer to output deratin g curve)
UL60950-1, TUV EN60950-1 approved
EN55022 class B conducted, EN610 00-3-2,3,
EN61000-4-2,3,4,5,6,8,11, ENV50204
2.6kg ; 6pcs / 16.6kg / 1.75CUFT
1500WwithPFC and Parallel Function1500WwithPFC and Parallel Function
. . . .
. . . . . .
. . . . . . . .
. . . .
. .
. . . . . . . . .
. . . . . .
. . . . . . . . . . .
. . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . .
278x 127x 83.5 mm
CA SE: 943
²
Section VI – Monitor and Control System
Control System Overview (Insight)
The Insight control system is used for a variety of functions, the most important of which is
ensuring that the transmitter continues to operate in a safe manner. The control system also
allows the user to monitor and control the transmitter from both the front panel and the remote
access port.
Five modules comprise the Insight control system. These modules work together to provide all
the functions of the control system. The modules are: User Interface, Coupler Conditioning, RF
Conditioning, Temperature Sensor, and the TxNET modules. The operation of each module is
outlined in the following sections.
For the TAUD-20-3 only, all three Power Amplifier chains are controlled by one User Interface
Board and all three Power amplifiers are monitored on one LCD screen. In case of an alarm,
the unit number and the fault will be displayed on the front panel (i.e. PA2 High Reflected
Power). During the alarm situation only the error screen will be displayed while the other two
units continue to run normally. The alarm buzzer will sound different on PA1, PA2 and PA3.
User Interface Module
The primary function of the User Interface module is, as the name suggests, providing the user
interface for the control system. This circuit board is mounted to the front panel of the
transmitter, directly behind the LCD display. The membrane switch on the front panel is also
connected to the User Interface module. These components together provide the user with the
ability to monitor the transmitter from the front panel.
The following parameters can be monitored from the front panel:
• Forward (incident) power at the transmitter output.
• Reflected (reverse) power at the transmitter output.
• DC voltage of the transmitter power supply.
• DC current for each pallet in the transmitter.
• Digital attenuation for input signal.
• Temperature of the heat sink of the transmitter.
• The time since the transmitter was last shut down.
Technalogix Ltd TAVD-500 Transmitter
VI-1
The hardware of the User Interface module is based around a microcontroller (U112). This
microcontroller interfaces directly with the LCD and the membrane switch to provide output and
receive input from the user. The microcontroller also communicates with the Coupler
Conditioning board over a Controller Area Network (CAN) bus. This communication is
facilitated by two ICs, U113 and U114, and passes through a CAT5 cable attached to connector
J106. The communication link with the Coupler Conditioning module allows the User Interface
module to receive information about the forward power, reflected power, and temperature of the
transmitter, as well as relay commands from the user to the rest of the system. If the transmitter
includes more than one amplifier enclosure, a second CAN connection will be present between
the User Interface module (J105) and the TxNET board to facilitate communication between
enclosures.
Other elements of the User Interface module are also controlled by the microcontroller. A
buzzer (BZ101), a status LED (D113), and a relay to control the backlight of the LCD (RL101),
are all controlled through a buffer (U116). In order for the User Interface module to monitor the
current draw of each pallet in the system, the DC supply wires pass through the User Interface
module on their way from the power supply to the pallets. The DC enters through connector
J101 (6-position) from the power supply, and exits through J102 (10-position) to go to the
pallets. As the current passes through shunt resistors (R117/R118, R120/R121, R123/R124,
R126/R127, R129/R130), the voltage drop is monitored by U101 through U105, buffered by
U106 through U108, and sent to the analog to digital converter integrated into the
microcontroller. There are up to five circuits for which the current is monitored by this system.
As the DC supply passes through the User Interface module, it undergoes filtering to ensure
that the supply to the pallets is as clean as possible. Each of the five circuits passes through a
network of transient voltage suppressors, capacitors, and inductors. Each connection is also
fused at the input to insure an over-current condition does not persist. The fuses are a
replaceable mini blade type fuse with a 42V voltage rating, and a current rating depending on
application.
Coupler Conditioning Module
The Coupler Conditioning module serves to monitor the output of the directional coupler which
provides a voltage proportional to the forward and reflected power at the output of the
transmitter. The Coupler Conditioning module also interfaces with each of the other boards in
the control system, acting as the hub of communications for the system. Lastly, the Coupler
Conditioning board sends and receives signals through the remote access port, via the TxNET
board.
The analog signals produced by the coupler for forward and reflected power are passed onto
the Coupler Conditioning module by connectors J206 and J207, respectively. Each signal is
then filtered by LC networks. The analog signals are converted to digital by an analog-to-digital
converter integrated into the microcontroller U202.
Technalogix Ltd TAVD-500 Transmitter
VI-2
Aside from taking readings from the coupler, the microcontroller on the coupler conditioning
module also interfaces with the RF Conditioning module (through J201) and the Temperature
Sensor (through J202). The microcontroller interfaces with the system CAN bus using U203
and U204. Through the CAN bus, the Coupler Conditioning board is able to communicate with
the User Interface module, and any other amplifier enclosures that are in the system.
The last task of the Coupler Conditioning board is to send and receive remote access signals to
and from the TxNET board. Two analog outputs, proportional to forward and reflected power
and produced by the digital-to-analog converter U207 after it receives input from the
microcontroller. The analog outputs are then buffered by U206 before being sent through J208
and J209 to the TxNET board. J208, along with J209, also bring the digital inputs and outputs
from the TxNET board to the Coupler Conditioning module. The digital signals are then
connected to the microcontroller through the opto-isolators U209 through U213.
RF Conditioning Module
The RF Conditioning board is located at the RF input of the amplifier. Its main function is to act
as a variable attenuator, so that the control system can add attenuation to the input of the
amplifier in order to limit the output power of the transmitter. The RF signal comes in to the RF
Conditioning module through J301 before it passes through a fixed attenuator (Pi-network)
made up of R301, R302, and R303. The signal then passes through the digitally-controlled
variable attenuator U302 before exiting through J303. The input control for the digital attenuator
comes from the Coupler Conditioning module through J304. The input signals are passed
through the opto-isolators U302, U303, and U304 before being sent to the digital attenuator. In
total, five control signals go to the digital attenuator, allowing for attenuations of up to 31dB in
1dB steps.
Temperature Sensor Module
The Temperature Sensor module is a small board mounted to the main heatsink of the amplifier.
The main purpose of the temperature sensor module is to take temperature readings of the
heatsink. The temperature sensor IC is U701 which, after it has taken a reading, relays the
digital information to the Coupler Conditioning module through J702. Also passing through
J702 is a driver disable signal coming from the Coupler Conditioning module. The Temperature
Sensor module simply takes this signal and passes it through to a pad, where a wire connects it
to the driver pallet.
Technalogix Ltd TAVD-500 Transmitter
VI-3
TxNET module
The TxNET module is simply a passive board that acts as an interface between the wiring on
the inside of the amplifier enclosure and connections on the outside of the enclosure. There is
a high power version for systems that have more than one amplifier enclosure and a low power
version, which does not have external enclosures aside from the modulator. The DB-25
connector for the remote port (J602) is attached to the TxNET module. The signals travelling
through this port are connected to the Coupler Conditioning module through J601 and J603.
The TxNET module also includes up to three straight through RJ45 connection pairs: J604 to
J605, J606 to J607, and J608 to J609. These connections are only used on systems with
multiple enclosures, to pass control signals between enclosures; otherwise a low power TxNET
is used.
Technalogix Ltd TAVD-500 Transmitter
VI-4
Remote Port
The remote port allows external control of the transmission system via the DB25. The Power
Amplifier enclosure does not include all the pins in the remote port like the Combiner/Filter
enclosure. The overall functions of each pin on the remote port are indicated in the following
table (see the Installation section for the specifics to each enclosure):
Pin Number Description
1 Ground
2 Forward power sample1
3 Reflected power sample1
4 Carrier off2
5 Carrier on2
6 Increase carrier level (level must have been decreased) 2
7 Decrease carrier level (1dB increments) 2
9 Reset2
11 High temperature flag3
12 High VSWR flag3
13 Amplifier overdriven flag3
14 +5Vdc
15 +3.3Vdc
16 Ground
17 Ground
Notes: 1. Analog output with voltage ranging from 0 to 5Vdc.
2. TTL level digital input, active on rising edge.
3. TTL level digital output, active high.
All other pins are not to be connected. Please see the Installation section for the specific pins
that are used for each enclosure.
Technalogix Ltd TAVD-500 Transmitter
VI-5
Fault Shutdowns
On the LCD (Liquid Crystal Display) the following messages may appear:
The Amplifier overdrive shutdown is set to 115%. If the Amplifier is being overdriven (the RF
output level is too high) the control system will automatically attenuate the RF input signal to the
PA. It will continue attenuating this signal until the RF output is below 115% total power.
If Reflected Power has been detected at the output of the transmitter, the unit will shut down for
4 seconds. This occurs 5 times – If the fault is clear the PA enables itself. If the fault still exists
after 5 times, the PA disables the carrier for 10 minutes and cycles until the fault clears. During
the disable time (10 minutes) the unit will still alarm with a High Reflected message on the front
panel.
Technalogix Ltd TAVD-500 Transmitter
VI-6
The control system monitors the temperature of a specific location of the heat sync. If this
temperature exceeds a threshold the control system will turn the RF output level down until this
temperature level is reached. The RF output level will automatically be brought back when it is
safe to do so.
Technalogix Ltd TAVD-500 Transmitter
VI-7
Monitor and Control System (Insight) Bills of Materials
Technalogix Ltd TAVD-500 Transmitter
VI-8
Page 1
ItemDesignationsQtyBin #DescriptionPackage
1U1121
ICT 32001
IC MICROCONTROLLER 256 BYTE RAM64QFP
2
C106, C107, C117, C118, C128, C129,
C141, C142, C148, C149, C16311
CAP 14902
CAPACITOR 0.01 uF 50V 10%SMD 0805
3
C108-116, C119-127, C130-140, C143-
145, C16133
CAP 17202
CAPACITOR 0.1uF 50V 10%SMD 0805
4C146, C1472
CAP 07202
CAPACITOR 33pF 50V 5%SMD 0805
5R101, R104, R107 R110, R1135
RES 5012
RESISTOR 2.7KΩSMD 0805
6C1621
CAP 19602
CAPACITOR 1uF, 50V SMD 0805
7R1321
RES 6492
RESISTOR 37.4KΩSMD 0805
8R1331
RES 5112
RESISTOR 3.3KΩSMD 0805
9
R140, R141, R144 R145, R146, R147
R150, R151, R1569
RES 5802
RESISTOR 10KΩSMD 0805
10
R134, R135, R136, R137, R138, R139,
R142, R143, R148 R149, R154, R15512
RES 4502
RESISTOR 1KΩSMD 0805
11R1521
RES 3212
RESISTOR 100ΩSMD 0805
12R119, R122, R125, R128, R131, R1536
RES 7042
RESISTOR 100KΩSMD 0805
13R1581
RES 4002
RESISTOR 430ΩSMD 0805
14R1601
RES 4662
RESISTOR 1.4KΩSMD 0805
15R1611
RES 6312
RESISTOR 27KΩSMD 0805
16R1621
RES 5512
RESISTOR 6.2KΩSMD 0805
17R1571
RES 1575
RESISTOR 4.7ΩSMD 2010
18
R117, R118, R120 R121, R123, R124
R126, R127, R129 R13010
RES 0086
RESISTOR 0.006Ω 1% 1WSMD 2512
19R1591
POT 0843
POTENTIOMETER 10KΩ4mm SMD
20
R102, R103, R105 R106, R108, R109
R111, R112, R114 R11510
RES 2346
RESISTOR 20
Ω 1WSMD 2512
21RN1011
RES 5810
RESISTOR NETWORK 10KΩSMT
22F1071
FUS 2901
RESETTABLE FUSE, POLYFUSE, 2ASMD
23F1081
FUS 1651
RESETTABLE FUSE, POLYFUSE, .5ASMD
24L106, L107, L108, L109, L1105
IND 0221
INDUCTOR 0.01uH1210
25Y1011
CLK 0002
6.00 MHz CRYSTALSMT
26U1111
ICT 56001
IC SUPERVISOR 2.70V LOWSOT23
27U1141
ICT 12000
IC TXRX 3.3V CAN8-SOIC
28U1131
ICT 12001
IC CAN CONTROLLER W/SPI18-SOIC
29U1151
ICT 48003
IC REG SIMPLE SWITCHERTO-263-5
30U1161
SEM 69000
IC DARL TRANS ARRAY16-SOIC
31U1171
ICT 48004
IC REG LINEAR LDOSOT223
32U1181
ICT 16000
IC VOLTAGE COMVERTER8-SOIC
Bill of Materials
Modified: 08/03/06
Circuit: User Interface Module (TV)
Revision: 1.03
CAP 22271
CAP 07202
SEM 29006
SEM 29005
SEM 09005
SEM 09010
SEM 14001
SEM 24000
R219
POT 0841
ICT 32033
ICT 12000
SEM 69000
ICT 04003
ICT 18000
ICT 46001
SWT 4003
SWT 0001
CON 31502
PCB 129
Bill of Materials - ASY129A
Circuit: Coupler Conditioning (D-Attn)
Revision: 1.10
Modified: 12/1/08
The heat sinks allow the amplifiers to operate at a cooler temperature and prevent overheating,
which helps the longevity of the entire system. Each heat sink has hollow fins, which help
dissipate the heat from the amplifiers faster than a conventional serrated or corrugated fin.
In addition to the cooling effects of the heat sinks, within the 500-watt power amplifier enclosure,
there are six fans that each provide 170 cubic feet per minute (CFM) of air flow (into zero static
pressure). There are three fans mounted at the front of the heat sink and three mounted at the
back end of the heat sink. The fans are mounted side-by-side to produce the best cooling for
the system and are operating in a push-pull configuration to assist with heat dissipation. The
fans are a 24Vdc variety, so there are series dropping resistors to drop the higher power supply
voltage down to a safe level.
Technalogix Ltd TAVD-500 Transmitter
VII-1
Section VIII - Installation
This section contains installation recommendations, unpacking, inspection, and installation
instructions for the power amplifier. We are sure that you are chomping at the bit to install your new
system, so we recommend that you read the following sections very carefully.
Building Recommendations
The quality of the building is of great importance if you are to expect long life and continued
performance from the power amplifier. The building must be clean, dry, temperature controlled and
secure. 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.
Technalogix Ltd.TAVD-500 Transmitter
VIII-1
Heating and Cooling Requirements
The environment’s temperature will contribute greatly to the length of the power amplifier’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.
The TAVD-5000 contains (3) DC ball bearing fans in each PA (push-pull configuration) and (2)
fans in each of the combiner/filter and power supply enclosure.
Technalogix Ltd.TAVD-500 Transmitter
VIII-2
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 transmitter or translator sites to lightning. 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 transmitting or translating equipment to operate on one circuit breaker. Each
transmitter or translator should have its own circuit breaker, so a failure in one does not shut off the
whole installation.
Technalogix Ltd.TAVD-500 Transmitter
VIII-3
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
in line of sight to the originating station all year round. The foliage will change with season.
Transmitting antennas can enhance or seriously impair the transmitter/translator output.
The selection, routing, and length of coaxial cable are extremely important in the installation. If ther e
is a 3 dB line loss in the cable between your unit’s output and the transmitting antenna, a 1,000-watt
unit will only deliver 500 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.
Pay attention to radial ice accumulation when designing the transmission system. It is not
uncommon for at least an inch of ice to build up on the tower and antenna. This in turn significantly
increases the weight, cross section, and wind loading of the system.
Attaching the transmission line to the tower is crucial to maintain a safe and reliable operation.
Nylon wire ties and electrical tape will breakdown in the sunlight and ultimately fail, creating a
potentially dangerous situation. It is important to use proper clamps and hoisting grips and also
ensure that the transmission line is grounded to the tower in several locations. When high currents
flow through the tower in the event of lightening strikes, some of that current will through the outer
conductors of the transmission lines. Due to the resistance difference between the steel tower and
copper transmission line, a significant voltage can be developed, often resulting in arcing between
the outer jacket and outer conductor, thus pitting the conductor.
Preventative maintenance is crucial in ensuring that safety is maintained. Specifically, check that
transmission line grounds are tight and are not missing any hardware. Frequently inspect support
clamps or spring hangers. Consider investing in an ice break, if you haven’t already done so, as
shards of falling ice can damage the transmission line – and if it is going to happen, it will happen at
an important time. Check the tower light photocells and conduit.
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. The bestdesigned 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. Be absolutely safe and certain about this aspect as human lives may be at
stake.
Technalogix Ltd.TAVD-500 Transmitter
VIII-4
Shelter Security
The FCC requires that the transmitter or 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. A 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.
Technalogix Ltd.TAVD-500 Transmitter
VIII-5
Unpacking and Inspection
Check the outside of the container. Carefully open the container and remove the power amplifier.
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 power amplifier 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 or fan failures. 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.
Technalogix Ltd.TAVD-500 Transmitter
VIII-6
Location and Function of Controls and Connectors (TAVD-500 Power Amplifier)
The following illustration depicts the location of the connectors when installing the 500-watt power
amplifier.
Technalogix Ltd.TAVD-500 Transmitter
VIII-7
POWER - Tactile button to turn carriers on and off.
NAVIGATE - Tactile button to move between menu items, or to refresh the screen after it
has timed out.
SELECT- Tactile button to select menu item, or to refresh the screen after it has timed
out.
RESET -Tactile button to reset microcontroller in control board. Also clears existing
faults. The amplifier will come back on with the soft start feature.
RF IN – RF input from modulator or processor. BNC connector, 50 ohm.
RF OUT – 500-watt (rms) RF output. Connects to combiner/filter enclosure. N
connector, 50 ohm.
REMOTE PORT -Port to monitor and control the amplifier externally. See “ Monitor and
Control” section for pin-out. Power amplifier has fault alarms only and
filter/combiner has fault alarms and controls.
Technalogix Ltd.TAVD-500 Transmitter
VIII-8
Location and Function of Controls and Connectors (Filter Enclosure)
The following illustration depicts the location of the connectors when installing the filter
enclosure.
Technalogix Ltd.TAVD-500 Transmitter
VIII-9
RF IN -RF inputs (500-watts each) from the power amplifier. N female connector,
50 ohm.
RF OUT –500-watt (rms) RF output. Connects to inline wattmeter (not supplied) and
antenna. 7/16”DIN female connector, 50 ohm.
Technalogix Ltd.TAVD-500 Transmitter
VIII-10
Initial Hook Up
1. Ensure that the antenna has been swept and has a return loss of greater than 20dB (VSWR
= 1.2:1). This should be done before connecting the antenna cable to the transmitter output.
2. Check that your video source is present.
3. Place the transmitter/translator in its permanent location near a receptacle supplying
required AC voltage.
DO NOT APPLY AC POWER AND TURN ON POWER TO THE
TRANSMITTER / TRANSLATOR AT THIS TIME SINCE THE RF OUTPUT
MUST BE PROPERLY LOADED BEFORE OPERATION.
4. Place an appropriate AC power line protector, conditioner, and/or surge suppressor across
the AC supply line.
5. Hook up the modulator or processor as shown in their respective manuals for a transmitter or
translator. Do not connect the modulated signal from the RF OUT on the modulator or
processor to RF IN on the power amplifiers at this time. Because of the characteristics of
transistor devices, the RF drive should not be connected to the power amplifier until after the
power supply and bias voltages are present and stable.
6. Ensure that modulator or processor RF output level is turned down as far as possible.
7. Hook up the PA out to the Filter in.
8. Connect the RF Output on the filter enclosure to the wattmeter directly (no cable in between)
and then the output of the inline wattmeter to the transmitting antenna cable.
9. Plug power supply into AC mains (220 Vac, single phase).
10. Leave the AC rocker switch to “off” position.
Technalogix Ltd.TAVD-500 Transmitter
VIII-11
Section IX - Operating Procedure
Assuming the previous installation instructions have been completed and cautions noted, and the
TAVD-500 power amplifier is ready to receive a properly modulated video and audio signal, proceed
with the following steps to place the system in operation. The TAVD-500 power amplifier has been
factory aligned for channel frequency (per system specification), signal levels and optimum
performance.
IT IS HIGHLY RECOMMENDED THAT YOU RUN YOUR SYSTEM INTO A DUMMY LOAD
BEFORE INSTALLING TO MAKE SURE THERE ARE NO DAMAGES CAUSED IN SHIPPING AND
THE UNIT IS RUNNING PROPERLY
1. Do not apply RF drive signal to the power amplifier at this time.
2. Verify that all control and RF cables are tight and properly seated in or on the mating connector.
3. Plug the modulator or processor into AC mains.
4. With the PA output loaded, plug the 3U power supply enclosure into 220V AC mains.
5. Switch AC rocker switch to “ON” position.
6. Verify that the power amplifier fans are all on.
7. Ensure that the modulator/processor is turned on and set up according to its instructions.
Depress the POWER tactile button to turn the unit on.
8. The internal soft start circuitry will turn the bias voltages off until the power supply to the
amplifier pallets is fully stable. The message on the LCD indicates when the soft start is running.
Once complete, the Forward and Reflected Power and Power Supply readings will appear on
the LCD in the filter and power amplifier enclosures.
9. After the soft start is complete, apply the RF drive signal (which still should be turned down)
between the modulator or processor and the power amplifier RF In. This ensures that the RF
drive signal is applied only after the power supply is stable and the bias voltages are applied to
the amplifier.
Technalogix Ltd TAVD-500 Transmitter
IX-1
10. The TAVD-500 LCDs show the user the present status of the amplifiers. Adjust RF output
power to desired level (see Important RF Power Notice in previous section). Verify that the FWD
Power reads 400 to 500 Watts on the PA enclosure. The output power level can be adjusted
using the modulator or processor’s RF output level adjust. Keep in mind that the system will
shut down should the forward RF output power level be exceeded.
11. Ideally, the RFL Power should read zero. However, should a high VSWR be detected, the
system will automatically shut down and cycle as previously described.
12. Verify that the power supply reads approximately 30 Volts DC (see supplied final inspection
sheet for factory settings of power supply levels) on the LCD of the power amplifier.
13. Look at the transmitted output using a suitable monitor. The picture and sound quality should be
clean and sharp. If the output picture and sound quality is unsatisfactory, check the input
signals, connections to the antenna system, antenna and transmission line VSWR, and the
physical condition of the antenna.
If reception problems are encountered, and the quality of transmission is satisfactory, the difficulty is
often with the receiving antenna or with obstructions in the path between the transmitter/translator
and receiver.
Technalogix Ltd TAVD-500 Transmitter
IX-2
Section X – Maintenance and Troubleshooting
Periodic Maintenance
If your unit employs a filter on the air inlet for the fans, the filter should be cleaned every 30 days. If
the equipment is operated in a severe dust environment, the filters on the inlet fan may need to be
cleaned more regularly. Turn the system off and unplug all of the AC inlet cords. The filter can be
lifted off the fan and cleaned using an air compressor at low pressure. While the filter is out, clean
the fan blades themselves with a small brush. The fans themselves do not need lubrication.
The interior of the cabinets should be cleaned and inspected annually. Turn the system off and
unplug all of the AC inlet cords. Remove the top lid by unscrewing the 6-32 machine screws.
Use extreme caution when working near the AC input terminal. The power
amplifier and power supply store hazardous capacitances and voltages.
Using either compressed air or a brush with soft bristles, loosen accumulated dust and dirt and then
vacuum the interior of the cabinet. Complete a visual inspection of the interior, making sure there
are no loose connections or discolorations on any components from heat. Nothing inside the power
amplifier enclosure exceeds a temperature that is not comfortable to the touch under normal
operating conditions, so any signs of discoloration indicate potential damage.
All modular components inside the enclosure are attached to aluminium mounting plates for easy
removal and replacement. Ensure that plates are secured and the mounting hardware is tight.
Technalogix Ltd TAVD-500 Transmitter
X-1
Troubleshooting
The first and most important aspect of troubleshooting anything is to be systematic. Note where
you have looked and what you found.
Look first for the obvious.
•Make a physical inspection of the entire facility. Are all necessary connections properly made?
Do you see any signs of obvious damage within the equipment?
• Is the AC power ‘ON’ to the site and the equipment? (Check fuses and circuit breakers if
necessary.)
• Are all the switches in the correct operating position?
• Is the input signal present?
• Check LCD readings for presence of forward and reflected power and 31 V DC supply levels.
The above is an aid in determining the fault if some aspect of the system is not operating. The
following table deals with quality of operation:
Symptom Possible
Correction
Fault
Horizontal bars in picture
(may roll either way
depending on phase)
Ensure modulator/processor
Diagonal lines in picture Interference Install EMI/RFI filter in AC line
Determine source and
AC grounding / AC
interference
Technalogix Ltd TAVD-500 Transmitter
X-2
Install EMI/RFI filter in AC line
and power amplifier share a
common ground
frequency of interfering signal
(spectrum analyzer may be
required)
Symptom Possible
Correction
Fault
High reflected power Incorrect load Ensure amplifier connected to
transmission line
Ensure correct antenna
impedance (50 ohms)
Check antenna tuning and
VSWR. Verify correct cable
for transmission line length
Check all cables for visible
damage (kinks, nicks or cuts)
Check all connectors for poor
connections, water or corrosion
Check alignment of antenna
Check for physical damage of
antenna, including ice build-up
Technalogix Ltd TAVD-500 Transmitter
X-3
Thank you
for choosing
Technalogix Ltd.
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