Instruction Manual

OM1002Solid State 145 MHz Power Amplifier

OM POWER, s. r. o. 930 30 Báč 126SLOVAKIA

E-mail: om-power@om-power.com

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TABLE OF CONTENTS

1. GENERAL INFORMATION

1.1. Introduction ……………………………………………………………….. 4

1.2. Specification …………………………………………………………….... 4

1.2.1. Parameters …………………………………………………………………. 4

1.2.2. Protection Circuits ………………………………………………………… 4

1.2.3. Indicators ………………………………………………………………….. 5

2. SAFETY INSTRUCTIONS ……………………………………………… 5

3. GENERAL DESCRIPTION ………………………………………………. 6

3.1. HF part ……………………………………………………………………. 6

3.2. Power Supply …………………………………………………………….. 8

3.3. Safety Devices ……………………………………………………………. 8

4. INSTALLATION ………………………………………………………… 9

4.1. Grounding ………………………………………………………………… 9

4.2. Coaxial Cable …………………………………………………………....... 9

4.3. Control Cable ………………………………………………….…………... 9

4.4. Main Supply ………………………………………………………………. 11

4.5. Cooling ……………………………………………………………………. 11

5. OPERATION ……………………………………………………………… 11

5.1. Operation Elements ……………………………………………………….. 12

5.2. Preparation for operation …...……………………………………………… 13

5.2.1. Display Menu ……………………………………………………………… 14

5.2.2. Settings Menu ……………………………………………………………… 15

5.2.2.1. Own text editing ………………………………………………………….. 16

5.2.2.2. Display delay ……………………………………………………………... 16

5.2.2.3. Bias delay ………………………………………………………………… 17

5.2.2.4. Preamplifier delay ………………………………………………………… 17

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5.2.2.5. Bias SSB No.1 ………………………………………………………….. 18

5.2.2.6. Bias CW No.1 ………………………………………………………….. 18

5.2.2.7. Software version ……………………………………………………….. 19

5.2.3. Operating mode ………………………………………………………… 19

6. MAINTENANCE ………………………………………………………. 23

6.1. Indication of Fault Conditions …………………………………………. 23

6.2. Fuse Replacement . .………………………………………………….... 24

6.3. Cleaning ……………………………………………………………....... 25

7. APPENDIX ……………………………………………………………... 26

7.1. Block Diagram ………………………………..………................................ 26

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1. GENERAL INFORMATION

1.1. Introduction

The OM Power model OM1002 is a single band, solid state amplifier, designed for dutyoperation on 2 meter’s amateur band with all modes and no time limit. It is equipped witha new Freescale high rugged N-channel double MOSFET. This amplifier is characterized bycompact design, small size and a low weight.

1.2. Specification

1.2.1. Parameters

Frequency Coverage 144 – 148 MHz Amateur BandPower Output 1000W in CW, 800W SSB (linearity), RTTY, AM, FM and digi, 50% duty cycle.Input Power 10 to 15 W for full output power 1000WInput Impedance 50 Ohm, VSWR < 1.3 : 1Power Gain Typically 19 dBOutput impedance 50 Ohm unbalancedMaximum output SWR 1,9 : 1 for full output power 1000WSWR protection: Automatic switching to STBY , when reflected power is

100W or higherIntermodulation distortion - 32 dBcSuppression of harmonics < -60 dBcMOSFET MRFE6VP61K25HR6Cooler 3 axial fans + 2 axial fans (power supply)Supplying 100 – 250VAC , 50 – 60 HzPower Supplies inside 50V DC switch mode PS 12V DC for logic and protection circuitsSize 270 mm x 200 mm x 345 mm [10.6” x 7.9” x 13.6”]

(Width x height x depth)Weight 12 kg ( 26.5 lb )

1.2.2. Protection Circuits

There is several special protection circuits used in the amplifier. They are activated when oneor more of next parameters exceed defined values or some unwanted occasion occurs.

· Output power too high· Reflected power too high· Drain current too high· Gain to low· DC voltage too low or DC voltage error· Input power too high (hardware protection & software protection)· Inside temperature too high· Soft start for power supply protection (PS feature)

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1.2.3. Indicators

There are few visible LED indicators on the front panel for information on operatingcondition, a few buttons and a graphic display.

LED Indicators STBY - Standby modeOPERATE - Operation mode

CW - CW mode PREAMP - Control voltage +12V DC for optional RX

preamplifier switchingFAULT - Failure

ON AIR - Transmit mode

Buttons UP – DWN - Listing in LCD menu - Scroll trough the alphabet in edit mode - Changing parameters OPER - Operation mode SET - confirms parameters - Cursor to the right in edit mode - Settings menu

PRE - Preamplifier ON - Edit mode start, cursor to the left in edit mode

CW/SSB - mode switch

OSD Indicator 140 x 16 dot graphic display to view:

- Display menu- Settings menu- Warning & fault messages

2. SAFETY INSTRUCTIONS

WARNING! Before you will start to install and operate power amplifier, read carefullynext safety instructions!

WARNING! AVOID CHILDREN to play around PA or to touch power amplifier orconnected cables in working condition, or to push anything into the fan holes!

WARNING! Never turn the amplifier on without the upper lid in place.

WARNING! The OM1002 amplifier is neither to be used in a WET or HUMIDenvironment nor to be exposed to RAINFALL!

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WARNING! Do not turn the amplifier on without having connected the ANTENNA orproperly rated DUMMY LOAD! A hazardous HF voltage may build up on the antennaconnector 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 supplyhas been disconnected. Take out power cord from the outlet!

CAUTION! The amplifier must be installed in such a way that free flow of hot air frominside is allowed. The amplifier must not be installed in a constrained surrounding (i.e.tight shelves etc.)

CAUTION! The amplifier must be properly grounded during operation.

CAUTION! During operation the amplifier must be installed in such a way that therear panel will stay accessible.

CAUTION! The amplifier is an A category product. In a household it can influenceother electric appliances. In such cases the user is to take proper actions to mitigate thisdisturbance.

CAUTION! Read this manual carefully. Follow all of instructions during installationand operation to avoid damage to the amplifier not covered by manufacturer’swarranty! Do not attempt to perform any change of hardware or software!

3. GENERAL DESCRIPTION

3.1. HF part

OM1002 power amplifier was designed to achieve the RF performance of the MOSFET,when applied to the 144 – 148 MHz frequency band. Design was tuned for performance at1000W CW output, 50VDC. It consists of „no tune“ distributed element matching circuitsdesigned to be as small as possible.

For operating it is important that adequate heat sinking was provided for the design.

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Look at the RF board

The coaxial transformer turns ratio was chosen to meet required impedance level and thelength of the coax was tuned to achieve maximum efficiency and maximum power transferbetween the device and its load impedance.

Top view on the opened OM1002

Input / Output Relay HF Board Output LPF

Supply Board for Control circuits Switch Mode Power Supply

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3.2. Power Supply

The amplifier uses two power supplies. A professional switch mode power supply 50V / 32Afor power amplifier, and small 12V power supply for logic and protection circuits.

Main power supply contains special soft start circuits, uses two fans, which are visible fromthe rear side of PA. It has its own logic to control these fans speed.

Power amplifier should be connected to any external source of AC in the range from 100VACto 250VAC, 50 or 60 Hz. It can be powered by a portable generator, for example.

Switch Mode Power Supply and theSupply Board. Two fuses are visible.

3.3. Safety Devices

Control and monitoring circuits ensure control and safety during malfunctions of the PA.These are on the Control board and the Protection board. Control board is located behind thefront panel. Protection board is visible on the right hand side of PA, close to the input/outputrelay.

Protection Board at the top

Input/Output Relay in the middle

Communication Board at the bottom (LAN)

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4. INSTALLATION

NOTERead this chapter carefully prior starting with installation. Before unpacking inspect shippingcarton first, if it is not damaged. Keep all of packing parts for possible future shipment. Checkunpacked power amplifier. If you find some damaging, contact your dealer immediately tokeep full warranty.

During installation go step by step according to next parts.

4.1. Grounding

CAUTIONThe amplifier has to be grounded properly! Connect the screw on the rear panel of theamplifier to your local grounding system with a copper cable; use a cross-section of 4mm2 at least.

Connect your transceiver to the same grounding system of your shack carefully!

Use minimum length of cables and make sure that the connections are both physically andelectrically sound. With poor grounding, you may risk damaging to your equipment, havingproblems 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 orsimilar cable. For the connection between the power amplifier and the antenna, Belden 9913or similar coaxial cable suited for high power is recommended. Both the INPUT andOUTPUT N sockets with Teflon insulation are used.

4.3. Control Cable

Control cable maintains TX / RX switching of the PA (TX GND). The cable is shielded. Onthe side of the power amplifier a CINCH-socket is used. On the side of your transceiver youhave to use a socket suitable for this transceiver. During transmitting the middle pin isconnected to the ground.

Amplifier uses one double coaxial relay for input and output (input and output are switched atthe same time). It has to be switched earlier than HF is applied (cold switching).

Modern transceivers have a time delay between PTT switching and power output.

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Rear view of the amplifier OM1002

RF Output RF Input AC Power Socket

PS Fans

LAN - Local Area Network connection for REMOTE CONTROL of PA (for future use)PREAMP - RCA Phono, +12V / 100mA for an external RX preamplifier switching

CAUTIONIf you are using an older transceiver or transmitters without time delay, we recommendto connect the PA in such a way that the transmit/receive switch (foot switch forexample) is connected with the KEY IN socket of the amplifier. The KEY OUT socket isto be connected with the PTT socket at the transceiver.

The amplifier is equipped with two safety devices, which ensure that the output relay is notswitched under power mistakenly (hot switching).

KEY IN - RCA Phono – Input signal PTT (switching voltage / current 5V /2 mA)KEY OUT - RCA Phono – Output signal PTT (maximum switching of 50V / 100mA)

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4.4. Main Supply

CAUTIONBe sure you got PA with properly terminated line cable, corresponding with your powersystem’s outlet. If not, contact your dealer. In such a case you should make the necessarychanges using a licensed electrician.

WARNING!Be sure that your power system is correctly wired and properly rated! To useadequately sized and connected grounding system is also very important.

4.5. Cooling

CAUTIONThe amplifier must be installed in such a way that free flow of hot air from the amplifieris allowed. Do not obstruct air intake and exhaust areas of the PA.

All of installed axial fans provide adequate cooling of the amplifier, even during long timeoperation. Three upper fans they are activated, when inside temperature exceeds 40 deg.Celsius. Their speed is gradually rising with increasing temperature. Two fans inside thepower supply start to operate depending on the current drawn by the MOSFET.

When the amplifier reaches inside temperature of 70 deg. Celsius, warning message„Amplifier is too hot” appears on the display. At 75 degrees protection circuit willautomatically blocked transmitting.

5. OPERATION

WARNING!Before switching PA on, make sure that amplifier is grounded, antenna or dummy loadis connected, and power cord is putted to the outlet.

CAUTIONDo not turn PA on for at least 2 hours after unpacking it and moving in its operatinglocation. Especially when amplifier was moved from a cold place to a warm one, becausenot visible condensation may develop inside, and this could result in damage of the PA.

CAUTIONBefore switching PA on, check connections between PA and TCVR.

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CAUTIONNever try to change antenna during a transmission to avoid warranty loss.

5.1. Operation Elements

There is couple of operational elements accessible and visible on the front panel.

STBY - Standby mode LED

OPERATE - Operation mode LED

CW - CW mode LED

PREAMP - Preamplifier „ON“ LED (+12V control voltage output)

FAULT - Failure LED

ON AIR - Transmitting mode LED

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OPER - short press to switch between Standby and Operation modeSET - long press (about 2,5 seconds) to enter the Settings menu (green LED is ON)

- short press to release the Settings menu (green LED is OFF)- short press to confirm parameters in the Settings menu- short press to move cursor to the right in editing mode- long press to release editing mode and confirms Own text

PRE - short press to switch preamplifier ON and OFF- short press to start editing mode in the Settings menu- short press to move cursor to the left in editing mode

CW/SSB - long press to change between CW (CW LED is ON) and SSB mode (LED is OFF)

UP–DWN - short press to list in LCD menu - short press to change parameters - short press to scroll trough the alphabet in editing mode

UP - long press to enter Hardware SETTINGS menu – not available for users - short press to release the SETTINGS menu

5.2. Preparation for operation

After turning on the power switch on the front panel power amplifier will automatically gointo standby mode.

NOTESome of next preparation steps are accessible only in standby mode.

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5.2.1. Display Menu

The graphic display shows couple of parameters or texts. In every line user can selectdifferent ones, using UP/DWN buttons (UP for upper line scroll, DWN for bottom linescroll) :

OM POWER amplifier - Own text – Bar graph for output power – PWR in watts +short bar graph - PWR in watts + REF in watts – PWR in watts + SWR – Pin in watts+ SWR – T1 in deg C – Um1 in Volts + Im1 in Amps – OM POWER amplifier - ……..

Have a look at some of combination examples:

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5.2.2. Settings Menu

Press SET button for about 2,5 seconds to enter Settings menu. Green LED in the button’scorner will light. The top line will display „Settings menu“, in the bottom line user can scrollthese parameters or texts:

Own text – Display delay – Bias delay – Preamplifier delay – Bias SSB No.1 – Bias CWNo.1 – Software version x.x – Own text - ………

Use UP/DWN button to select desired parameter for editing or viewing.

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5.2.2.1. Own text editing

„Settings menu“ appears in the upper line. Select „Own text“ in the bottom line. To openediting mode press PRE.

Cursor will appear in the first position. You can move it to the right using SET, or to the leftusing PRE. Insert proper letter or number in the chosen start position using UP/DWN keys.Move cursor to the next position and then insert next letter, number, sign or space......etc.Maximum 20 characters.

When you finish editing, press the SET button for about 2,5 seconds to confirm new text andto leave editing . New text replaces the original „Own text“ in the Display Menu.

5.2.2.2. Display delay

Display delay is the period during which the display remains lit when the PA will remain atrest (in standby mode for example). The default value is 140 seconds.

„Settings menu“ appears in the upper line. Select „Display delay“ in the bottom line. To openediting mode press PRE.

To change time use UP/DWN keys. Value can be changed in 20 seconds steps. Confirm theselected value by pressing SET.

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5.2.2.3. Bias delay

Electronic Bias Settings (EBS) is one of significant feature of the power amplifier. It allows toset low drain current after pressing the PTT regardless of whether you have CW or SSBmode, until RF signal is no present at the input. At the moment when RF signal comes to theinput of PA, bias will automatically change its value depending on the selected operationmode. For CW it will stay low (Id = 200mA), for SSB it will move operating point to ABclass ( Id = 2,7A)...... EBS is default activated – Bias delay is set to ON.

To deactivate EBS you have to set Bias delay to OFF. I such a case bias value after pressingthe PTT will depend on the working mode.

„Settings menu“ appears in the upper line. Select „Bias delay“ in the bottom line. To openedit mode press PRE. Use UP/DWN buttons to change status. Press SET to confirm newvalue and to leave editing.

5.2.2.4. Preamplifier delay

You can control switching of an external RX preamplifier from the PA using PRE button inoperation mode. For reliable working condition and safety of preamplifier there is importantto set some delay of its switching according to the PTT. Possible range is from 0 to 255ms.Default value is 20 ms.

„Settings menu“ appears in the upper line. Select „Preamplifier delay“ in the bottom line. Toopen edit mode press PRE. Use UP/DWN buttons to change value. Confirm the selectedvalue by pressing SET.

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5.2.2.5. Bias SSB No.1

This parameter will be checked without the possibility to change it. When „Settings menu“appears in the upper line, select „Bias SSB No.1“ in the bottom line. To view SSB Bias pressPRE. In couple of seconds you will see the value of drain current in the second line (about2,7A). Do not leave this status active long time. Use the SET button to release checking.

5.2.2.6. Bias CW No.1

This parameter will be checked without the possibility to change it. When „Settings menu“appears in the upper line, select „Bias CW No.1“ in the bottom line. To view CW Bias pressPRE. In couple of seconds you will see the value of drain current in the first line (about0,2A). Do not leave this status active long time. Use the SET button to release checking.

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5.2.2.7. Software version

The last thing you can view in the Settings menu, is Software version, visible in the secondline of the display.

NOTEDo not forget to leave Settings menu by pressing the SET button. Green LED in the button’scorner turns OFF.

5.2.3. Operating mode

CAUTIONIn STBY the amplifier is in bypass-mode and your transceiver is directly connected tothe antenna. Maximum allowed power in bypass mode is 100 Watts! Passing RF poweris not measured and displayed if PA is either in standby mode or turned OFF.

Push the OPER button to activate operation mode. At that moment 50V DC will beconnected to the MOSFET.

In the OPERATE mode you can select CW or SSB transmitting mode, you can scroll Displaymenu and select switching of an external RX preamplifier. You can not activate Settingsmenu.

NOTESetting of CW or SSB mode actually means only a bias adjustment (class C or class AB modeof PA) and is not strictly tied to the operating mode of the connected transceiver.

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WARNING!Before you push PTT for the first time, set the RF power in your transceiver to theminimum (from 3 to 5 watts) !!!

Select parameters in the Display menu as is visible in the previous or next picture and pressPTT. You can check measured parameters of PA.

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Previous picture shows input power 5.5W, output power 366W. Power gain from input tooutput of the PA was 18.2 dB. When operation mode of the PA was changed from CW toSSB, output power increased (TCVR output power remained the same). This is because theoperation class of PA was changed from class C to class AB.

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Previous pictures they show couple of different kinds of visual display during the same test.This test gave us result of power gain 20.2 dB in class AB.

If all looks ok, you can increase RF power from the transceiver slowly and check importantparameters of PA. Do not exceed the output power of 1000 watts in CW operation mode andabout 800 watts in SSB, AM, FM and digi operation mode even if more is reachable.

NOTEWe recommend using the maximum output power of 800 watts to maintain good linearity ofoutput signal in SSB or AM mode.

CAUTIONNever use CW mode in the PA, if this is driven by SSB signal, otherwise strong andunpleasant intermodulation distortion occurs!

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CAUTIONCheck the temperature of PA during digi modes operation. Decrease the output power,when warning message „Amplifier is too hot“ appears. Output power of about 800 wattsshould be ok for 50% of duty cycle.

6. MAINTENANCE

If a fault condition appears during the operation of the amplifier, the safety circuits ofOM1002 will react, the FAULT LED lights. There are several fault or warning messagespossible to appear on the display, when some of the protection will be activated. The OM1002power amplifier can show one of the following messages:

1. „PowerOut is too high”2. „Reflected power too high”3. „PowerIn is too high” or „Overdrive error“4. „Gain is too low“5. „Voltage is too low“6. „Amplifier is too hot“7. „Current is too high“

When the output power of the PA exceed limit value, „PowerOut is too high“ fault messageappears on the display, the amplifier will stay in the operation mode, but transmitting will beblocked. Decrease the input power to allow transmits again.

When reflected the power of the PA exceed 100 watts, „Reflected power too high“ faultmessage appears on the display, amplifier will stay in operation mode, but transmitting will beblocked. In such a case try to decrease input power first, or improve matching and adaptbetter the impedance of your antenna.

When the input power of the PA exceed limit value, „PowerIn is too high“ fault messageappears on the display, amplifier will stay in the operation mode, but transmitting will beblocked. Decrease the input power to allow transmits again. There are two limit values. First(20% above full driving level) is for software protection. In this case software will blocktransmitting; PA will stay in OPER mode. Second and very fast protection will be activated,when the input power exceeds 50% above full driving level. In this moment input RF signalwill be switched immediately to the dummy load and PA will go to STBY mode. Message

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„Overdriving error“ appears. Decrease the input power under maximum driving level, setOPER mode again to continue transmitting.

When one half of the double MOSFET will be broken for example, or some fault in the outputcircuit presents, output power of the PA will decrease rapidly. Fault message „Gain is toolow“ appears, amplifier will stay in OPER mode, but transmitting will be blocked. In thissituation contact the manufacturer for the assistance.

In the case of the main power supply failure, when voltage drops below 42 volts, faultmessage „Voltage is too low“ appears, the amplifier will stay in operation mode andtransmitting will be blocked. You have to check inside fuse first. If fault persists, contact themanufacturer or your dealer for the assistance.

When the amplifier reaches inside temperature of 70 deg. Celsius, warning message„Amplifier is too hot” appears on the display. At 75 degrees protection circuit willautomatically block transmitting (fault condition). You have to decrease the power or waitcouple of minutes to be ready transmitting again.

When current of the PA exceed the limit value, „Current is too high“ fault message appearson the display, amplifier will stay in operation mode and transmitting will be blocked.Decrease input power first and try to transmit again. If this will not help and current will stayhigh, contact the manufacturer for assistance.

If you turn the power amplifier ON and no LED will be illuminated, display stays dark, checkmains first, and then check fuses inside the PA (see next part for more details).

CAUTIONIf MOSFET is destroyed, do NOT attempt to replace it, in any case! Contact themanufacturer immediately.

WARNING!Never try to change or move any part inside the amplifier except of internal fuses.Substitution of parts may void intrinsic safety!

6.2. Fuse Replacemeent

There are two fuses installed inside the OM1002 power amplifier. They are located on thesupply board on the left hand side of the PA, above the main power supply. The user isallowed to change these fuses.

WARNING!Before opening the upper lid of the amplifier make sure that power supply has beendisconnected. Take out power cord from the outlet!

Power amplifier OM1002 uses one fuse 10 Amps „T” type 5 x 20 mm for main 50V DCpower supply and one fuse 500mA „T“ type for small 12V DC power supply.

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6.3. Cleaning

To prevent damage to the amplifier surfaces and the plastic components do not use aggressivechemicals for cleaning. Do not open the amplifier for cleaning. Outer surface may be safelyaccomplished by using piece of soft cotton cloth moistured with clean water or windowcleaner.

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7. APPENDIX

7.1. Block Diagram of OM1002 Power Amplifier