Array Solutions Array Solutions X8NOM2000 Amateur Radio Service Linear HF Amplifier User Manual OM2000

Array Solutions dba Array Solutions Amateur Radio Service Linear HF Amplifier OM2000

Contents

Users Manual OM2000+

Exhibit 6 Page 1 from 35 Exhibit 6: User’s Manual External Radio Frequency Power Amplifier OM2000+ Model 2000+ Array Solutions 2611 North Beltline Rd Suite 109 Sunnyvale, Texas 75182 USA Tel: 214 954 7140 fax: 214 954 7142 E-mail: info@arraysolutions.com
Exhibit 6 Page 2 from 35 TABLE OF CONTENTS 1. GENERAL INFORMATION ..................................................................... 4 2.1. Introduction …………………………………………………………………. 4 2.2. Specification …………………………………………………………………. 4 2.2.1. Parameters …………………………………………………………………. 4 2.2.2. Protection Circuits …………………………………………………………………. 4 2.2.3. Indicators …………………………………………………………………. 5 2.2.4. Features …………………………………………………………………. 5 2. SAFETY INSTRUCTIONS …………………………………………………………………. 6 3. GENERAL DESCRIPTION …………………………………………………………………. 7 3.1. HF part …………………………………………………………………. 7 3.2. Power Supply …………………………………………………………………. 8 3.3. Safety Devices …………………………………………………………………. 9 4. INSTALLATION …………………………………………………………………. 9 4.1. Grounding …………………………………………………………………. 10 4.2. Coaxial Cable …………………………………………………………………. 10 4.3. Control Cable …………………………………………………………………. 10 4.4. Main Supply …………………………………………………………………. 11 4.5. Cooling …………………………………………………………………. 11 5. OPERATION …………………………………………………………………. 12 5.1. Operation Elements …………………………………………………………………. 12 5.2. Preparation for operation ………………………………………………………………. 14 5.2.1. Display menu …………………………………………………………………. 15 5.2.2. Settings menu …………………………………………………………………. 17 5.2.3. Service menu …………………………………………………………………. 19 5.3. Operation mode …………………………………………………………………. 22 5.4. Tuning of the Power Amplifier ……………………………………………………… 24 6. MAINTENANCE …………………………………………………………………. 28 6.1. Indication of Fault Conditions ……………………………………………………… 28
Exhibit 6 Page 3 from 35 6.2. Fuse Replacement …………………………………………………………………. 31 6.3. Tube Replacement …………………………………………………………………. 31 6.4. Cleaning …………………………………………………………………. 31 7. APPENDIX …………………………………………………………………. 32 7.1. Primary AC selection …………………………………………………………………. 32 7.2. Removing the HV Transformer ……………………………………………………. 33 7.3. Block Diagram of the OM2000+ Power Amplifier ………………………… 35
Exhibit 6 Page 4 from 35 1. GENERAL INFORMATION 1.1. Introduction he OM Power model OM2000+ is designed for all short wave amateur bands from 1.8 to 29.7 MHz (including WARC bands) plus 50 MHZ and all modes. It is equipped with a ceramic tetrode FU-728F. 1.2. Specification 1.2.1. Parameters Frequency Coverage Amateur Bands 1.8 – 29.7 MHz including WARC + 50 MHz Power Output 1500 W in SSB/CW on HF bands, 1500 W in CW/SSB on 6m 1500 W in RTTY Input Power Usually 70W for full Output Power Input Impedance 50 Ohm, VSWR < 1.5 : 1 Power Gain 15 dB Output Impedance 50 Ohm unbalanced Maximum Output SWR 2 : 1 SWR protection Automatic switching to STBY, when reflected power is 250W or higher Intermodulation distortion 32dB below nominal output Suppression of harmonics < -50 dBc Tubes FU-728F Ceramic tetrode Cooler Centrifugal blower + Axial blower Power supply Switchable 220V, 230V, 240V, 50/60 Hz Transformers One toroidal transformer 3kVA Dimensions 15,4“ x7,7” x 14,6” (width x height x depth) Weight 24 kg / 52 lbs 1.2.2. Protection Circuits There are several protection circuits used in the amplifier. They are activated when one or more of next parameters exceed defined values or some unwanted occasion occurs.  VSWR too high  Anode current too high  Anode voltage error  Screen current too high  Screen voltage error T
Exhibit 6 Page 5 from 35  Grid current too high  Grid voltage error  Heating voltage error  Mistuning of PA  Temperature to high  Soft start for fuses protection  “switch-on blocking “ at opened amplifier 1.2.3. Indicators Number of indicators visible on the front panel will inform you about value of some parameters or operation status: OLED display 4 x 20 characters Analog Wattmeter Double system meter for forward and reflected power measuring LED Indicators ON AIR – amplifier in transmitting mode STBY – standby mode FAULT – failure, switching off for abt. 4 sec ON – ON status 1.2.4. Features Manufacturer implemented some of the company’s current development results with most wanted operating and safety features into this new model:  High level of protections  Antenna switch for 3 different antennas  Memory for faults and warnings, easy maintenance  Automatic set-up anode current (BIAS) – no need to adjust manually after changing the tube  Temperature controlled 2-speed centrifugal blower ( turbine ) + axial blower  Full QSK with silent relay  Many operational parameters to display  Easy transport due to detachable HV transformer  The smallest and lightest 2000 W PA on the market
Exhibit 6 Page 6 from 35 2. SAFETY INSTRUCTIONS WARNING! DANGEROUS HIGH VOLTAGE INSIDE! The power amplifier is using high voltage up to 3000V DC, which is very dangerous for human life! Read next safety instructions carefully first, before you will start to install and operate power amplifier! NEVER VIOLATE NEXT RULES! WARNING! NEVER ALLOW CHILDREN to play around PA or to touch power amplifier or connected cables in working condition, or to push anything into the case holes! WARNING! Never turn the amplifier on without the upper lid in place. DO NOT ATTEMPT TO SHORT OR BYPASS safety switch under upper lid! WARNING! The OM2000+ amplifier is neither to be used in a WET or HUMID environment nor to be exposed to RAINFALL! WARNING! Do not turn the amplifier ON without having connected the ANTENNA or properly rated DUMMY LOAD! A hazardous HF voltage may build up on the antenna connector after turning the amplifier on with no antenna or dummy load connected! WARNING! Before opening the upper lid of the amplifier make sure that power supply has been disconnected AT LEAST 10 minutes allowing the electrolytic capacitors to discharge fully. Disconnect power cord from the outlet! WARNING! Any work inside the PA (internal fuses replacement, tube replacement, etc.) can be carried out only by professionally qualified person!
Exhibit 6 Page 7 from 35 CAUTION The amplifier must be installed in such a way that free flow of hot air from the tube is allowed. The amplifier must not be installed in a constrained surrounding (i.e. tight shelves etc.). During long time operation ventilation grid can reach high temperature. Do not touch it! CAUTION The amplifier must be properly grounded during operation. CAUTION During operation the amplifier must be installed in such a way that the rear side remains accessible. CAUTION The amplifier is an A category product. In a household it can influence other electric appliances. In such cases the user is to take proper actions to mitigate this disturbance. CAUTION Read this manual carefully. Fallow all of instructions during installation and operation to avoid damage to the amplifier not covered by manufacturer´s warranty! Do not attempt to perform any change of hardware or software! 3. GENERAL DESCRIPTION 3.1. HF part his amplifier is using a ceramic tetrode FU-728F in a grounded-cathode circuit (input into control grids). The OM2000+ amplifier achieves excellent linearity by the voltage stabilization of the control grid bias and the screen voltage. The power input is given to the control grids, using a broadband input circuit with an input impedance of 50 Ohms. This adaptable input circuitry ensures a good input SWR (better than 1.5 : 1) on all amateur bands. T
Exhibit 6 Page 8 from 35 The output of the amplifier is a Pi-L circuit. The ceramic capacitor for TUNE and LOAD are divided. This enables the amplifier to be tuned exactly and makes it possible to easily return to the previously set positions after band changes. Top view on the opened OM2000+ Tetrode FU728F Antenna Switch Blower Power Supply Board Switch-ON Board Output Pi-L Circuit Tuning Capacitor Subpanel HV transformer 3.2. Power Supply Power amplifier is using one 3 KVA toroidal transformer. A soft start is provided using relays and resistors (placed on the switch-ON board). The high voltage is made by combining 4 x 530V AC (total abt. 2950V DC) @ 1.2A. Each has its own rectifier and filter. In the high voltage circuit, safety resistors are employed to protect the amplifier against overload (placed on the power supply board). The separated supply for screen grid is regulated by stabilization with MOSFET and delivers abt. 330V DC at 100mA. Control grid voltage is also stabilized (-120V DC). Change of stabilized first grid voltage is controlled by the software (EBS for example).
Exhibit 6 Page 9 from 35 3 kVA toroidal transformer is visible on the left side. Switch-ON board is in the front, Power supply board behind it. CAUTION Primary section of the transformer is switchable for 220 - 240 VAC. Factory setting is 230VAC. If the AC voltage in your network is 220 or 240 Volts, you need to set the correct value before first starting of the PA. See part 7.1. for more information. 3.3. Safety Devices Control and monitoring circuits ensure control and safety during malfunctions of the PA. These are placed on the Control board, which is located on the chassis subpanel. One of the important safety element is mechanical switch for AC blocking at opened amplifier. 4. INSTALLATION NOTE Read this chapter carefully prior you will start installation. Before unpacking inspect shipping carton first, if it is not damaged. Keep all of packing parts for possible future shipment. Check unpacked power amplifier. If you find some damaging, contact your dealer immediately to keep full warranty. During installation go step by step according to the next parts. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 10 from 35 4.1. Grounding CAUTION The amplifier has to be grounded properly! Connect the screw on the rear panel of the amplifier to your local grounding system with a copper cable; use a cross-section of 4 mm2 at least. Connect your transceiver to the same grounding system of your shack carefully! Use minimum length cables and make certain that the connections are both physically and electrically sound. With poor grounding, you may risk damaging your equipment, having problems with TVI/BCI or your transmitted signal may be distorted. 4.2. Coaxial Cable The output of the transceiver is to be connected to the input of the amplifier via RG58 or similar cable. For the connection between the power amplifier and the antenna, RG213 or similar coaxial cable suited for high power is recommended. All the INPUT and three OUTPUT (ANT1, ANT2, ANT3) SO-239 sockets with Teflon insulation are used. Rier view of the amplifier OM2000+ Fuses Mains Plug HF Outputs Blower Grounding point Control HF Input 4.3. Control Cable Control cable maintains TX / RX switching of the PA (TX GND). The cable is shielded. On the side of the power amplifier a CINCH-socket is used. On the side of your transceiver you have to use a socket suitable for this transceiver. During transmitting the middle pin is connected to the ground. The relays of the OM2000+ have to be switched earlier than HF is applied (cold switching). Modern transceivers they have a time delay between PTT switching and power output.
Exhibit 6 Page 11 from 35 CAUTION If you are using an older transceiver or transmitters without time delay, we recommend to connect the PA in such a way that the transmit/receive switch (foot switch for example) is connected with the KEY IN socket of the amplifier. The KEY OUT socket is to be connected with the PTT socket at the transceiver. The amplifier is equipped with safety devices, which ensure that the output relay is not switched under power mistakenly (hot switching). KEY IN RCA Phono - Input signal PTT switching voltage / current - 5V /2mA) KEY OUT RCA Phono - Output signal PTT (maximum switching of 30V / 50mA) 4.4. Main Supply CAUTION Be sure you got PA with properly terminated line cable, corresponding with your power system’s outlet. If not, contact your dealer. In such a case you should make the necessary changes using a licensed electrician. WARNING! Be sure that your power system is correctly wired and properly rated! To use adequately sized and connected grounding system is also very important. 4.5. Cooling CAUTION The amplifier must be installed in such a way that free flow of hot air from the tube is allowed. Do not obstruct air intake and exhaust areas of the PA. The centrifugal blower provides the necessary cooling of the amplifier, even during long contests. The blower is activated by switching the PA on and it is turned off when cooling is finished (approx. 1-5 min after switching off the PA depending on the temperature of the tube). Blower speed (2 steps) is setting automatically according to the tube temperature. Detailed view on the tube and blower area. Antenna switch (above) is installed inside the metal box. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 12 from 35 5. OPERATION WARNING! Before switching PA on, make sure that amplifier is grounded, antenna or dummy load is connected, and line cord is putted to the outlet. Be sure you selected AC input by 7.1. CAUTION Before switching PA on, check all connections between PA and TCVR. CAUTION Do not turn PA on for at least 2 hours after unpacking it and locating in its operating location. Especially when amplifier is moved from a cold place to a warm one because not visible condensation may develop, and this could result in damage to the high voltage circuits of the PA. CAUTION Never try to change antenna output during a transmission to avoid warranty loss. NOTE When you decide to have a short operating break, place the amplifier to the standby mode rather than switch it off. 5.1. Operation elements There is couple of operational elements accessible or visible on the front panel.
Exhibit 6 Page 13 from 35 BAND - Band selector switch TUNE - Anode capacitor for tuning (higher frequencies to "0"; lower frequencies to „100“). LOAD - Output capacitor tunes antenna load resistance to the amplifier. Capacity is low at „100“ and high at "0" on the scale. WATMETER - Analog double system meter for forward and reflected power measuring ON / OFF - Long press (abt. 1 sec.) to switch PA ON/OFF RESET - Short press to reset faults or warnings 0 / I Power ON small 12V APU for logic and protection circuits You can switch Antenna ports even if PA is switched OFF. S1 S2 S3 S4
Exhibit 6 Page 14 from 35 ON AIR - Transmitting mode LED STBY - Standby mode LED FAULT - Failure LED ON - PA is „ON“ LED S1 - OPER / STBY - Press to switch between Standby and Operation mode ESC - Return to the previous level S2 - MENU - Enter the Menu DOWN - Scroll down S3 - DSP - Change display (DSP1, DSP2, DSP3) UP - Scroll up S4 - ANT - Change Antenna output (ANT1, ANT2, ANT3) ENT - Confirm the selection More functions of S1-S4 buttons will be described in next parts of this manual. 5.2. Preparation for operation The first necessary thing after connecting AC to the power amplifier is switching main (green) switch to „ I “. Welcome message and then starting information appears on the display: After switching main switch ON welcome message appears shortly. Starting message shows which antenna is connected. To switch PA ON press ON-OFF button for abt. 1 second. Warming time takes abt. 210 seconds. It is possible to enter MENU during this time, but with limited possibilities (display settings can be changed, for example). You can change ANT output, if necessary. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 15 from 35 If you change DSP during warming time, you lost count down information. Press BACK (S1) to restore starting message. When warming time expires, PA switches itself automatically to the STBY mode. You have two possibilities now - switch PA to OPER mode and start operation, OR to go thru MENU and submenus to set display parameters, some hardware parameters or to enter the service menu. In the STBY mode Antenna output can be changed (ANT1, ANT2, ANT3) by pressing S4. Display information can be changed, too. Press S3 to do it. There are 3 different display settings possible in the OM2000+. To set display parameters, go to the next part of this manual for more details. 5.2.1. Display menu The OLED display shows couple of parameters or texts. Display has 4 lines. Three of them are editable. In every line user can select different parameters, using MENU. See next pictures. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 16 from 35 After pressing MENU (S2) S1–S4 buttons changed their functions. To edit display parameters, press DISP button. Press DIS1 to edit first display. Now you can define parameters for first three rows. Start with first line, press 1Row button. Go UP or DOWN to select desired parameter. Press ENT to confirm selection. There are 4 possible settings for the first line (one bar-graph or three pairs of different parameters):  Forward bar-graph  Forward Power _ Reflected Power  Forward Power _ SWR  Plate voltage Up _ Plate current Ip Second and third line are divided to the left and the right side, editable independently. To each of these positions one of the 15 different parameters should be set. If you finish first line settings, press ESC to go back to the row selection. To start edit second line, press 2Row button. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 17 from 35 S2 and S3 now changed their functions. To edit left side of the second line, press LEFT button. Go UP or DOWN to select desired parameter. Press ENT to confirm selection. If you finish left side settings, press ESC to go back to the side selection. To start edit right side, press RIGHT button….etc. Second and third line programmable parameters are:  Forward Power  Reflected Power  Input Power  SWR  TUNE  Temperature  Frequency  Plate voltage – Up  Plate current – Ip  Screen voltage – Us  Screen current – Is  Screen current – graph  Grid voltage – Ug  Grid current Ig  Heating voltage – Uf 5.2.2. Settings menu Settings menu offers EBS settings, factory default parameters restoring and display contrast settings (software version 6.1. or higher). Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 18 from 35 Electronic Bias Settings (EBS) is one of significant feature of the power amplifier. It allows to set low plate current after pressing the PTT regardless of whether you have CW or SSB mode, until RF signal is no present at the input. At the moment when RF signal comes to the input of PA, bias will automatically change to its working value. EBS level means level of the Input power, where EBS starts working. Default EBS value is 0.2 W. We recommend using EBS ON. Significant accompaniment of used EBS is temperature reducing. To enter Settings menu, go to MENU first, then press SET button. Use UP or DOWN button to select EBS ON/OFF. Press ENT to enter EBS status settings. Press ON or OFF to set status of EBS. Press ENT to confirm selection. Press ESC to go one level back. Use UP or DOWN button to select EBS level parameter. Press ENT to enter EBS level settings. Use UP or DOWN button to set EBS level value. Press ENT to confirm EBS level value. Press ESC to go one level back. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 19 from 35 If you wish to restore factory default parameters, use UP or DOWN button to select Restore default parameters. Then press ENT. Press YES for 1 second to confirm restoring. Use UP or DOWN button to select LCD contrast. Press ENT. Use UP or DOWN button to set contrast value. Press ENT to confirm settings. 5.2.3. Service menu In the Service menu it is possible to verify software version. This menu allows user to check total operating hours and listing in the memory, where reported faults and warning messages are stored. You can display particularly warning messages and particularly error messages. See chapter 6 for more information regarding to warnings and faults occurrence. There you can find a coding table together with a limited values for the safety circuits activation also. In the Service menu a value of EBS1 and EBS2 can be automatically adjusted. This is used for example when it is necessary to make adjustment after replacing the tube. Automatic control of EBS, however, can be done at any time. EBS1 default value is 20mA of Ip, EBS2 default value is 250mA of Ip. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 20 from 35 Use Service menu after replacing the tube. This is step No. 1. To enter Service menu, go to the MENU first, then press SERV button. Use UP or DOWN button to check software version. Use UP or DOWN button to select Time ON parameter. Press ENT to see total operating hours of the PA. Press ESC to go back to the Service menu. Use UP or DOWN button to select Faults. Press ENT to see fault numbers or letters (see the table in chapter 6). Press ESC to go back to the Service menu. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 21 from 35 Use UP or DOWN button to select Warnings. Press ENT to see warning numbers or letters (see the table in chapter 6). Press ESC to go back to the Service menu. Use this procedure after replacing the tube. This is step No. 2. Scroll UP or DOWN to select EBS1 settings. Press ENT to start automatic adjustment of EBS1 (20 mA). Automatically increasing of the grid voltage (decrease of the negative value) causes a gradual increase in the plate current. In the moment, when Ip reaches 20mA, adjustment stops. Press ESC after stopping. Use this procedure after replacing the tube. This is step No. 3. Scroll UP or DOWN to select EBS2 settings. Press ENT to start automatic adjustment of EBS2 (250 mA). Automatically increasing of the grid voltage (decrease of the negative value) causes a gradual increase in the plate current. In the moment, when Ip reaches 250mA, adjustment stops. Press ESC after stopping. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 22 from 35 Use UP or DOWN to select Calibration Ip & Is. Press ENT to do it. Ip and Is calibration runs in the background. Result only is visible on the display. Press ESC to go one level back. 5.3. Operation mode CAUTION In STBY the amplifier is in bypass-mode and your transceiver is directly connected to the antenna. Maximum allowed power in bypass mode is 100 Watts! Passing RF power is measured with analog wattmeter only. It is not displayed if PA is either in standby mode or turned OFF. Press OPER to activate operation mode. STBY LED switched OFF. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 23 from 35 Changing of DSP allows user to watch couple of basic parameters of the PA in operation mode without input RF signal. Notice: These are three default display settings (software version 6.1.) Check all connections again. Set BAND selector, TUNE and LOAD capacitors according to TCVR parameters and delivered tuning table (see next part for more details). Apply low input power and press PTT. Check Analog wattmeter first. Try to tune PA for maximum output power and minimum SWR. Using foot switch in „KEY IN” we activated transmitting mode of the PA first. “ON AIR” LED is ON. EBS is active (Ip = 20mA) In the transmitting mode all 4 buttons (S1, S2, S3, and S4) are blocked! An example of standard tuning procedure using Analog wattmeter. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 24 from 35 5.4. Tuning of the Power Amplifier The OM2000+ power amplifier is operated in class AB. Thus it’s possible to obtain a maximum output power at excellent linearity. For this purpose the amplifier has to be tuned carefully. CAUTION The operation of a mistuned PA will cause malfunctions, the increase of grid current and problems with TVI/BCI. CAUTION If the input power is higher than 10W and the power amplifier is NOT correctly tuned, the safety devices will switch it to STBY. After switching the amplifier to STBY, you need to switch it back to the OPER mode by pressing RESET button shortly. A tuning table is delivered with the power amplifier. For coarse tuning select a band with BAND switch and choose the setting of “TUNE” and “LOAD” capacitors according to the table. Band (MHz) Tune Load Input PWR (W) Output PWR (W) 1.845 70 45 75 1500 3.630 69 51 72 1500 7.050 50 90 71 1500 10.125 72 28 72 1500 14.175 69 40 70 1500 18.150 81 48 69 1500 21.230 47 67 65 1500 24.940 61 64 59 1500 28.450 33 76 52 1500 50.200 22 90 64 1500 NOTE Delivered tuning table was made for 50 Ohm loading of PA (dummy load). Each amplifier should have different values depending on used frequency and used type of antenna. Make your own table valid for your real conditions. There are two ways how to do fine tuning. The first method uses a gradual increase in the input power when tuning the PA (as most operators accustomed). In every case we recommend adjust the display for both of methods so it shows two parameters important for fine tuning - TUNE and Is graph (> l <).
Exhibit 6 Page 25 from 35 Press OPER to enter operation mode. Apply low input power and press PTT. Be sure you selected right BAND, TUNE and LOAD knob positions. If you made some mistake, fault message appears: Safety circuit stopped transmitting, fault LED is ON (Fault code 4 is saving to the memory). Release PTT, set proper positions of BAND, TUNE and LOAD according to the table and press PTT again. Another mistake can occur, if you have antenna connected to the wrong output. In such a case „SWR is too high“ error message appears. Change antenna output using S4 button. This is not an optimal result, TUNE indicator must go between both arrows. Use TUNE knob to get maximum output power and LOAD knob to get indicator between arrows. Another example of not optimal result, TUNE indicator must go between both arrows. Use TUNE knob to get maximum output power and LOAD knob to get indicator between arrows (in arrows direction). This is a good result of tuning. Now increase input power slowly and watch the display. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 26 from 35 Two of important information is visible – screen current increased, but still is within the allowed limits. Turn LOAD knob slightly in arrows direction to get TUNE indicator between arrows. Display indicates correct tuning of the Power amplifier. Remember Always use TUNE knob to get maximum output power. Use LOAD knob to get TUNE indicator on the display to the middle position between both arrows. Simultaneously check if Is graph indicator stays within the boundaries. Repeat both steps more times. Proper operation mode of FU-728F requires the plate voltage to be close to 3 kV. If anode voltage without RF power is much lower, watch the heating voltage, too. Normally, heating voltage must be in boundaries from 8.5 to 9 V without RF signal (DSP3). Heating voltage level is a reliable indicator of correct AC selector adjustment. If you see heating voltage lower than 8.5V without RF signal, change primary AC voltage selector one step down (if possible). Conversely, if the voltage is higher than 9V, try to move AC selector one step up (for example from 220 to 230 VAC). Check heating voltage under full load (full output power), also. If the heating voltage without RF signal is OK but under full load drops more than 1.5 V, this relates to the „soft“ AC network and is solvable only by „changing“ the AC network... Without RF power the plate voltage is OK. Without RF power the plate voltage is 2.85 kV. Check the heating voltage, too. If it is below 8.5 V, this indicates the need to change AC selector position one step down (for example from 230 to 220 VAC). Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 27 from 35 To start the second method of fine tuning, press S2 (TUNE) button in OPER mode. PA is in the operation mode. After TUNE button (S2) was pressed, it changes its function. Now STOP is blinking. Do not press STOP button yet! Apply input power according tune table (or lower) for selected band and press PTT. Use TUNE knob to get maximum output power. Use LOAD knob to get Is graph indicator within the boundaries. Display shows properly tuned PA. TUNE indicator is in the middle, Screen current is higher, but still inside the limits. After proper fine tuning release PTT and press STOP button. PA is now prepared for operation. View on the properly tuned PA. Analog wattmeter shows forwarded and reflected power. After this procedure the amplifier is tuned correctly and ready to give 1500 W output power in all operation modes. At optimal tuning and full output power a positive max. 50mA current goes through the second grid. CAUTION If the amplifier demonstrate any malfunctions during tuning or it does not behave in accordance witch the description, interrupt the tuning procedure immediately and check the amplifier! Be sure not to do any mistakes in choosing bands or TUNE/LOAD values! Be sure that VSWR is not higher than 2:1 and input power is LOW! After excluding possible human mistakes you will be able to work for long time with this amplifier! Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 28 from 35 6. MAINTENANCE 6.1. Indication of Fault Conditions If a fault condition appears during the operation of the amplifier, the safety circuits of OM2000+ will react. There are several warning or fault messages possible to appear on the display, when some of the protection will be activated. The OM2000+ power amplifier can report one of the following messages: 1 - Power Out is too high 2 - Refl. power too high 3 - Power In is too high 4 - Low output power (tune) 5 - Plate current too high 6 - Grid current is high 7 - Screen current error 8 - N/A 9 - Heating voltage error A - HARD FAULT B - Plate voltage error C - Grid voltage is low D - Screen voltage error E - SWR is too high F - Amplifier is too hot NOTE Most of safety circuits are preset for two levels of exceedances. First level is a warning level. In such a case a warning message appears on the display, fault LED will flash, but power amplifier will stay in normal operation. See the table below for warning and fault conditions. NOTE When a fault condition appears during the tuning or operation of the amplifier, the safety circuits will block transmitting and FAULT LED starts blinking. The amplifier stays in OPER mode. After approx. 1 sec the control circuits will automatically switch the amplifier back to the transmitting mode. If problem persists, safety circuit will react again. CAUTION If the fault will repeat 3 times during 10 seconds, the safety circuits will turn the amplifier to STBY mode. FAULT LED stays ON. To cancel fault status, press RESET shortly. Power amplifier will stay in STBY mode. All the warning and fault messages are stored in the memory. You can display particularly warning messages and particularly error messages. See the Service menu in the 5.2.3., how to select service display. All of messages are stored and displayed as a numbers or letters as indicated in this chapter (1 - 9; A - F). They are stored one by one to the memory. You can see them on the display in three lines, on every second display position (maximum 10 per row, maximum 30 messages for warnings and 30 messages for errors). If memory is full, every new message will delete oldest one and move rest of
Exhibit 6 Page 29 from 35 them one position back. It means that every time last 30 messages are visible on the display. Next table shows limited values for the safety circuits activation. Fault code Parameter Warning level Fault level 1 Power Output is too high 2200W 1700W (50MHz) 2300W 1800 (50MHz) 2 Reflected power is too high 250W 300W 3 Power Input is too high 80W 100W 4 Low output power (tune) > 3dB below* 5 Plate current is too high 1.8A 2.0A 6 Grid current is too high 10mA 20mA 7 Screen current is too high 50mA 60mA 8 N/A N/A 9 Heating voltage error +/- 2V *** +/- 2.5V A HARD FAULT (from 3.1 version) Plate current >2.5A **** B Plate voltage error Min. 1800V Max. 3400V Min. 1500V Max. 3500V C Grid voltage is low -40V -30V D Screen voltage error Min. 250V Max. 400V Min. 220V Max. 420V E SWR is too high 3:1 F Amplifier is too hot 80 deg. C ***** 90 deg. C ***** 1. * This fault indicates mistuning of the PA. It works for Input power higher than 10W. If output power decreases more than 3dB below value corresponding with the applied Input power, fault message „Low output power“ appears. You have to tune the PA correctly. 2. *** When the heating voltage exceeds boundaries 9V +/- 2V, warning message „Heating voltage error“ appears. Check proper position of AC selector (page 25). Heating voltage without RF signal should be between 8.5 and 9V. 3. **** „HARD FAULT” appears if the plate current exceeds 2.5 A. In such a situation hardware will immediately disconnect high voltage from the plate. Fault is signed with the letter „A“ in the memory. If error occurs frequently, consult this situation with the manufacturer, please. 4. ***** If temperature sensor inside the PA detects of 80 deg. Celsius, warning message „Amplifier is too hot“ appears on the display. At 90 degrees protection circuit will automatically block transmitting (fault condition). You have to decrease the power or wait couple of minutes to be ready transmitting again. Fault is signed with the letter „F“ in the memory.
Exhibit 6 Page 30 from 35 An example shows situation when Input power is too high. By pressing PTT safety circuit will react quickly, error message appears and FAULT LED starts blinking. In this case screen current exceeds limited value (60mA). After abt. 1 sec. PA returns to TX mode. Reduce Input power to avoid fault repeating. This is the situation, when problem with high Input power persists. Safety circuits reacted 3 times, and then switched PA to STBY mode. Permanent fault appears. To return PA to the normal operation, decrease Input power first, then reset fault status and go back to the OPER mode. If resistor R1 or fuse F3 is damaged, safety circuit stops starting of the PA and fault message appears on the display. It is necessary to replace the damaged component. Fuse F3 Resistor R1 If there is a fault condition, always try to remove the cause first. If it is not a hardware failure, it usually succeeds. For example high VSWR, high Input power, mistune of PA, high temperature, etc. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 31 from 35 In the case of some hardware failure or if your power amplifier is not working properly, please contact the manufacturer or your dealer. WARNING! Never try to change or move any part inside the amplifier except of tube or fuses. Substitution of parts may void intrinsic safety! Manufacturer’s contacts: OM POWER, s.r.o. 930 30 Báč 126 SLOVAKIA Email: om-power@om-power.com 6.2. Fuse Replacement The user is allowed to change mains fuses (6.3 x 32mm), accessible from the rear panel, only. In the case of fuse (fuses) interruption inside the power amplifier, exchange can be carried out only by professionally qualified person! Internal fuses are located mainly on the SWITCH-on board (next to the HV transformer). One special fuse is used in the model OM2000+. In the case of an accidental discharges in the tube this fuse saves HV supply circuits. Fuse 6.3. Tube Replacement In the case of vacuum tube damaging, contact the manufacturer or your dealer for ordering new one. You will get instructuions how to change it. Exchange can be carried out only by professionally qualified person! After tube replacing automatic BIAS adjustment must be done. Read Service menu (5.2.3.) and pictures on page No. 20 for more details. 6.4. Cleaning To prevent damage to amplifier surface and plastic components do not use aggressive chemicals for cleaning. Do not open the amplifier for cleaning. Outer surface may be safely accomplished by using piece of soft cotton cloth moistured with clean water or window cleaner. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 32 from 35 7. APPENDIX 7.1. Primary AC voltage selection Primary section of the HV transformer is switchable for three values of AC voltage (220, 230, 240V). Factory settings is 230VAC. Before first starting of the PA we recommend to check the correct value according to the AC voltage in your network. Change the settings, if necessary. Side view on the opened OM2000+ HV Transformer AC Selector
Exhibit 6 Page 33 from 35 Remove the upper lid first. On the right side of the PA, next to the HV transformer there are two PCBs mounted. On the left upper side of the front (Switch-ON) board connector J6 is located. Use flat screwdriver or finger and press carefully the white stick to release contact and move upper end of the white jumper to the proper position, if necessary. Jumper must be connected between bottom contact and one of remaining contacts. AC voltage is marked next to every contact. NOTE AC selector range can be changed in the production according to the specific conditions in individual countries. 7.2. Removing the HV Transformer For simpler and easier transport of the PA, HV transformer can be removed and taken separately. This distributes the weight of the PA (24 kg) about half and half. Follow next steps to do it. 1. Remove upper lid from the PA. 2. Turn the PA on the left side (transformer is up). 3. Disconnect 3 connectors from the front board and 1 connector from the rear board. 4. Release 4 screws from the bottom side of the PA. Use Philips screwdriver P2. During the release of the last 2 screws hold the transformer by hand. Do not worry about its weight, it will move down just 1 cm and remains on the central rung of the PA. 5. Use both hands to take transformer away from the chassis. Watch the released terminals, when moving the transformer! Do not damage transformer insulation during removing and transportation. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 34 from 35 Weight of the PA was distributed (transformer has 12 kg, rest of the PA has cca 12 kg, too). When refitting the transformer, watch to the correct location of individual sections and wires. NOTE Manufacturer reserves the right to make future changes in the way of connecting the transformer to the board. Allways mark the position of the terminals before disconnecting the transformer. Type of supported TCVR and working frequency are visible on the display. AUTO LED is ON.
Exhibit 6 Page 35 from 35 7.3. Block Diagram of OM2000+ Power Amplifier J4J12J3Ext. blowerJ10!J8 K1K6CONTROL BOARDDISPLAYANT SWITCHK2 K1K1J3A3A2A1K3K7K2K1K11K4K8J3J2J1K3J1 J11 K1K2J15 J14J8J9J7J2J13AC INJ424VRev.: 10.2.2014K2 K1Cover SWOM 2000+ block diagram L8L7SW 1cSW 1bSW 1aFU728fRele GSKEY INKEY OUTTR 1BlowerONSW ON BOARD HV SUPPLYMETER BOARDOUTPUTACINPUTPWR METERSCREEN BOARDINPUT BOARD1R1 2147C2211L1021L62T 16A2111F 4AF32112T 16A2121321K1211453121L4221212121212121212121212121211212211 2121

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