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350-Watt VHF LB Digital Transmitter 

 

Chapter 1, Introduction 

DT325B, Rev. 0 

  1-3 

all items sent to the Field Service 
Department regardless of whether the 
item was originally manufactured by 
Axcera. 
 
When equipment is sent to the field on 
loan, the RMA# is included with the unit. 
The RMA# is intended to be used for the 
return of the unit to Axcera. In addition, 
all shipping material should be retained 
for the return of the unit to Axcera. 
Replacement assemblies are also sent 
with the RMA# to allow for the proper 
routing of the exchanged hardware. 
 
Failure to close out this type of RMA# will 
normally result in the customer being 
invoiced for the value of the loaner item 
or the exchange assembly. 
 
When shipping an item to Axcera, please 
include the RMA# on the packing list and 
on the Axcera-provided shipping 
container. The packing slip should also 
include contact information and a brief 
description of why the unit is being 
returned. 
 
Please forward all RMA items to: 
 

Axcera  
103 Freedom Drive 
P.O. Box 525 
Lawrence, PA 15055-0525  USA 

 
For more information concerning this 
procedure, call Axcera Field Service at 

1-724-873-8100 

or by fax

 

at 

1-724-873-8105

 
Axcera can also be contacted through e-
mail at [email protected] and on the Web 
at www.axcera.com

 
1.6 Warranty for Axcera Products – 
Limited One-Year Warranty 

 
Axcera warrants each new product that 
it has manufactured and sold against 
defects in material and workmanship 
under normal use and service for a 
period of one (1) year from the date of 

shipment from Axcera's plant, when 
operated in accordance with Axcera's 
operating instructions. This warranty 
shall not apply to tubes, fuses, 
batteries, or bulbs. 
 
Warranties are valid only when and if 
(a) Axcera receives prompt written 
notice of breach within the period of 
warranty, (b) the defective product is 
properly packed and returned by the 
buyer (transportation and insurance 
prepaid), and (c) Axcera determines, in 
its sole judgment, that the product is 
defective and not subject to any misuse, 
neglect, improper installation, 
negligence, accident, or (unless 
authorized in writing by Axcera) repair 
or alteration. Axcera’s exclusive liability 
for any personal and/or property 
damage (including direct, consequential, 
or incidental) caused by the breach of 
any or all warranties, shall be limited to 
the following: (a) repairing or replacing 
(in Axcera's sole discretion) any 
defective parts free of charge (F.O.B. 
Axcera's plant) and/or (b) crediting (in 
Axcera's sole discretion) all or a portion 
of the purchase price to the buyer. 
 
Equipment furnished by Axcera, but not 
bearing its trade name, shall bear no 
warranties other than the special hours-
of-use or other warranties extended by 
or enforceable against the manufacturer 
at the time of delivery to the buyer. 
 

NO WARRANTIES, WHETHER 
STATUTORY, EXPRESSED, OR 
IMPLIED, AND NO WARRANTIES OF 
MERCHANTABILITY, FITNESS FOR 
ANY PARTICULAR PURPOSE, OR 
FREEDOM FROM INFRINGEMENT, 
OR THE LIKE, OTHER THAN AS 
SPECIFIED IN PATENT LIABILITY 
ARTICLES, AND IN THIS ARTICLE, 
SHALL APPLY TO THE EQUIPMENT 
FURNISHED HEREUNDER. 
 

 

Содержание DT325B

Страница 1: ...INSTRUCTION MANUAL DT325B 350 Watt Digital VHF Low Band Transmitter AXCERA LLC 103 FREEDOM DRIVE P O BOX 525 LAWRENCE PA 15055 0525 USA 724 873 8100 FAX 724 873 8105 www axcera com info axcera com...

Страница 2: ...emote Connections 2 9 CHAPTER 3 INSTALLATION AND SETUP PROCEDURES 3 1 Site Considerations 3 1 3 2 Unpacking and Installation of the Cabinet and Trays 3 4 3 3 Input and Output Connections to the Transm...

Страница 3: ...odule Replacement 5 1 5 3 VHF Amplifier Tray 5 1 5 3 1 AGC Control Board 5 1 5 3 2 Phase Shifter Board 5 2 5 3 3 Filter Amplifier Board 5 2 5 3 4 VHF Low Band Amplifier Board 5 2 5 3 5 Overdrive Prote...

Страница 4: ...er Amplifier Chassis Assembly Front View 2 1 2 2 Rear view Driver Amplifier Chassis Assembly 2 9 3 1 1 kW Minimum Ventilation Configuration 3 4 3 2 Front and Rear view Driver Amplifier Chassis Assembl...

Страница 5: ...tter Device Data Access Screen 3 10 3 7 Menu 13 Transmitter Configuration Access Screen 3 10 3 8 Menu 20 Error List Display Screen 3 10 3 9 Menu 30 Transmitter Device Details Screen 3 10 3 10 Menu 30...

Страница 6: ...es that make up the tray 1 2 Assembly Designation Numbers Axcera has assigned assembly numbers Ax designations such as A1 where x 1 2 3 etc to all assemblies modules and boards in the system These des...

Страница 7: ...duct until becoming familiar with the equipment If in doubt refer all servicing questions to qualified Axcera service personnel Replacement Parts When replacement parts are used be sure that the parts...

Страница 8: ...hip under normal use and service for a period of one 1 year from the date of shipment from Axcera s plant when operated in accordance with Axcera s operating instructions This warranty shall not apply...

Страница 9: ...TS TO THE SYSTEM RADIO FREQUENCY RADIATION HAZARD MICROWAVE RF AMPLIFIERS AND TUBES GENERATE HAZARDOUS RF RADIATION THAT CAN CAUSE SEVERE INJURY INCLUDING CATARACTS WHICH CAN RESULT IN BLINDNESS SOME...

Страница 10: ...with one hand and push down on his forehead with the other This opens the airway Sometimes doing this will let the person breathe again by himself 3 If he is still not breathing begin rescue breathing...

Страница 11: ...TT 90 60 100 000 100 KILOWATTS 80 50 10 000 10 KILOWATTS 70 40 1 000 1 KILOWATT 60 30 100 1 HECTROWATT 50 20 50 47 17 20 43 13 10 1 DECAWATT 40 10 1 1 WATT 30 0 77 137 7 07V 0 1 1 DECIWATT 20 10 67 12...

Страница 12: ...0 8327 Canadian gallon fluid ounce fl oz milliliters ml 29 57353 British Thermal Unit watt W 0 2930711 per hour Btu hr horsepower hp watt W 746 NOMENCLATURE OF FREQUENCY BANDS FREQUENCY RANGE DESIGNAT...

Страница 13: ...350 Watt VHF LB Digital Transmitter Chapter 1 Introduction DT325B Rev 0 1 8 RETURN LOSS VS VSWR 1 001 1 01 1 1 2 0 VSWR 0 10 20 30 40 50 60 70 R E T U R N L O S S dB...

Страница 14: ...ndwidth DC Direct Current D A Digital to analog dB Decibel dBm Decibel referenced to 1 milliwatt dBmV Decibel referenced to 1 millivolt dBw Decibel referenced to 1 watt FEC Forward Error Correction FM...

Страница 15: ...AC input line of 220 VAC at 40 amps that connects to the AC Distribution Panel which distributes the AC through AC power cords to the VHF exciter driver chassis and the VHF amplifier tray The DT325B...

Страница 16: ...al is returned FAULT red or green Red indicates that a problem has occurred in the transmitter The transmitter will be Muted or placed in Standby until the problem is corrected DC OK red or green Gree...

Страница 17: ...e channel mask filter so that its linear distortions can be seen When a nonlinear adaptive equalizer is being calculated the transmitter sample is taken before the channel mask filter so that the dist...

Страница 18: ...tector Voltage Level and also the VSWR Cutback protection if the Reflected Power level increases above the preset level Two voltages 28 VDC from the internal switching power supply and 12 VDC from the...

Страница 19: ...vel of the tray 1 to 3 VDC Power Supply Reads the voltage from the switching power supply 28 VDC S1 Switch Meter Current Uses Switch S2 to indicate the current of transistor devices Selects the curren...

Страница 20: ...ter 2 5 System Operation When the transmitter is in operate as set by the menu screen located on the Control Monitoring Module the 32 VDC stage of the Power Supply in the Control Monitoring Module is...

Страница 21: ...tering Standby Mode Similar to the operate mode the standby mode is entered various different ways These are A low on the Remote Transmitter Stand By line Depressing the STB key on selected front pane...

Страница 22: ...have been designed to function even if covered with dust a heavy buildup of dust dirt or insects will affect the cooling of the components This could lead to a thermal shutdown or the premature failu...

Страница 23: ...ect drawing and Table 2 9 TB30 and TB31 are 18 position terminal blocks that are removable from their sockets to make connections easier Just grasp and pull connector straight out After connections ar...

Страница 24: ...he transmitter power is to be raised RMT Power Lower TB30 9 Discrete Open Collector Input A pull down to ground on this line indicates that the transmitter power is to be lowered RMT System Reflect Po...

Страница 25: ...cale factor is 100 0 80V NOTE The RMT RF System Interlock at TB30 5 provides the customer with a means of connecting the transmitter to protection circuits for the loads thermal switches combiners or...

Страница 26: ...and without excessive humidity An ideal environment will require temperature in the range of 40 F to 70 F throughout the year reasonably low humidity and a dust free room This is rarely attainable in...

Страница 27: ...certain conditions 3 Do not isolate the front of the transmitter from the back with the thought of air conditioning only the front of the unit Cooling air is drawn in at the front of all transmitters...

Страница 28: ...ters should not rely on the internal blower to exhaust cooling air at elevations above 4000 feet For external venting the air vent on the cabinet top must be increased to an 8 diameter for a 50 W 100...

Страница 29: ...stem driver amplifier chassis and VHF amplifier tray also the harmonic filter bandpass filter couplers and the installation material from the crates and boxes Remove the straps that hold the cabinets...

Страница 30: ...t of the AC junction box mounted near the upper right hand rear portion of the cabinet terminals 1 and 2 220 VAC and terminal 3 chassis ground See Figure 3 3 Figure 3 3 AC Input Box Assembly Check tha...

Страница 31: ...F Loop Thru Output 50O J10 BNC External 10 MHz Reference Input From Axciter 50O J12 BNC NOT USED MPEG Input 50O J13 BNC Downconverter IF Output To Axciter 50O J68 J15 BNC Digital IF I P From Axciter 5...

Страница 32: ...s the output power level is being checked observe the LCD screen reading in the Reflected Power position If the Reflected Power is very high above 10 a problem may exist with the output coaxial lines...

Страница 33: ...when the DC outputs that connect to the modules in the transmitter are present 3 4 2 Front Panel LCD Screen for the Driver Amplifier Chassis Assembly A 4 x 20 display located on the front of the Cont...

Страница 34: ...ter is in Standby the OPR characters appear in the lower right By pushing the right most button located under the display the operator will place the Transmitter in Operate When the transmitter is in...

Страница 35: ...display returns to Menu 10 Main Screen If the key is activated the display returns to Menu 12 the Transmitter Device Data Access Screen Table 3 8 Menu 20 Error List Display Screen This screen of the...

Страница 36: ...TION STATUS RUNNING N A MEASURED SIGNAL TO NOISE 32 6dB N A PLL STATUS LOCKED N A SMTE310 INPUT STATUS OK N A DEMOD FUNCTION STATUS OK N A FX VERSION 1 013 N A Axciter Details NB VERSION 0 029 N A D C...

Страница 37: ...ange is made to a screen within the Set Up Menus when you go to the next menu a new screen asks if you accept the change or want to return to the previous menu to reconsider the changes made To accept...

Страница 38: ...nu 40 5 Transmitter Set up Serial Address Screen This screen allows the user to set the serial address of the transmitter The default address is 5 This value and all other set up parameters are stored...

Страница 39: ...the fault is not fixed the transmitter will enable measure power and if above this value plus five percent it will again shut down for five minutes If the system s reflected output power exceeds the...

Страница 40: ...the split connects to J4 The AC line 2 input connects from J1 3 to the F2 fuse The AC line 2 input after the F2 fuse is split with one line connected back to Jack J1 at Pin 5 which becomes the AC Line...

Страница 41: ...t low on pin 20 by either the programming port or the external watchdog IC U2 a FET Q1 inverts the reset signal to a high that connects to the control lines of U5 an analog switch The closed contacts...

Страница 42: ...transfer to the display is wired for read and write control RB1 is the connector to a Rabbit Semiconductor RCM4300 This Ethernet enabled controller polls the U1 microcontroller on the same serial line...

Страница 43: ...forward biased current will flow from ground through the LED the transistor and the current limiting resistors in the collector to the 12 VDC source The effected LED will light With the LED control l...

Страница 44: ...is Assembly The RF output from the upconverter at the upconverter RF output jack J23 a BNC connector The RF is cabled to the S input Jack on the A10 2 Way Splitter One output of the splitter connects...

Страница 45: ...ccurs the AGC Control Board generates a Fault Output at J1 which is connected to J4 on the Filter Amplifier Board The Fault cuts back the RF Signal level using the Pin Diode Attenuator Circuit located...

Страница 46: ...that consists of CR1 and U1A The gain of amplifier U1D is controlled by detector gain pot R11 which is set to 4 VDC as measured at TP1 The set output of U1D is connected to the comparator IC U1B The t...

Страница 47: ...level is combined with the AGC reference inputs at J2 and J6 2 which produces the AGC output at J1 which connects to the automatic level control circuit on the Filter Amplifier Board for the output p...

Страница 48: ...d by the jumper from TB1 5 to TB1 6 to the Phase Shifter Board the Filter Amplifier Board and the Overdrive Protection Board The Current Metering Board also supplies sample outputs of the operating cu...

Страница 49: ...he Tray as set by R60 VSWR Cutback on the AGC Control Board is cutback to maintain a 20 Reflected Output level The Red LED DS4 VSWR Cutback located on the front panel remains lit until the Reflected l...

Страница 50: ...R38 which adjusts the gain of U2C The output of U2C is split and connected to J5 6 and J5 5 DC O P 3 The 12 VDC needed for the operation of Op Amps U1 and U2 enters the board at J5 10 The voltage is...

Страница 51: ...Upconverter and Controller Power Supply can then be gently pulled from the unit After removal of the failed module slide the replacement module in place and make certain it connects to the backplane b...

Страница 52: ...resistor on the Filter Amplifier Board and adjust R13 for 25 Volts Using Ohms Law E I x R E 250 mA x 1 E 250 mV 5 3 4 A2 A1 VHF Low Band Amplifier Board 1198 1605 Appendix D This board has 20 dB of ga...

Страница 53: ...located on the AGC Control Board Then adjust R59 VSWR Cutback Adjust located on the AGC Control Board until DS4 the Red VSWR Cutback LED mounted on the front panel lights This sets up the VSWR Cutback...

Страница 54: ...e number entered until the monitored reading is 1 5 Volts 5 5 2 Setting up of the Overdrive Threshold On the Axciter Upconverter Downconverter Screen set the Overdrive Threshold to 1 7 Volts by select...

Страница 55: ...ng the Driver AmplifierChassis NOTE Do not adjust R38 on A4 the Triple Peak Detector Board 1159713 It is factory set for 7 to 8 VDC typical AGC Reference to the VHF Amplifier Tray and any readjustment...

Страница 56: ...APPENDIX A DT325B SYSTEM SPECIFICATIONS...

Страница 57: ...he companion upconverter The upconverter provides a pre correct ed output directly to the high gain final power amplifier modules three PAs in the 1000W unit The entire package is housed in a single 1...

Страница 58: ...mber of PAs 1 2 3 4 5 6 Input Power Line Voltage Volts 1 208 or 240 10 Power Requirements Single Phase 50 or 60 Hz Size H x W x D 69 x22 x34 69 x44 x34 OperationalTemperature Range 0 to 50 derate 2 C...

Страница 59: ...APPENDIX B SYSTEM DRAWINGS...

Страница 60: ...350 Watt Digital VHF LB Transmitter Appendix B System Drawings DT325B Rev 0 B 1 DT325B DT325B Transmitter w Axciter Interconnect 1311143 Triple Peak Detector Board Schematic 1160522...

Страница 61: ...APPENDIX C EXCITER DRIVER CHASSIS ASSEMBLY DRAWINGS...

Страница 62: ...LX Schematic 1310081 NOTE Information and drawings on the Axciter Modulator Tray 1305842 and the Upconverter Module 1310226 and Downconverter Module 1311157 are found in the separate Axciter Manual E...

Страница 63: ...APPENDIX D VHF LOW BAND AMPLIFIER TRAY DRAWINGS...

Страница 64: ...Overdrive Protection Board Schematic 1198 3601 Phase Shifter Board Schematic 1198 3602 VHF Low Band Amplifier Board Schematic 1198 3605 VHF Filter Amplifier Board Schematic 1198 3606 3 Way Splitter B...

Страница 65: ...50 Watt Digital VHF LB Transmitter Appendix D VHF LB Amplifier Tray Drawings DT325B Rev 0 D 2 AGC Control Board Schematic 1306481 400 Watt VHF Amplifier Assembly 1304348 Delta RF Data Sheet P400 VHF L...

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