Emtron dx-3 Specifications

OPERATING MANUAL EMTRON DX-3 HF LINEAR AMPLIFIER April 2005 Emtron DIVISION OF EMONA ELECTRONICS PTY. LTD. 92-94 Wentworth Avenue, Sydney 2010,

105.2 RF connections RF INPUT The RF input is an SO-239 female connector. A 50 ohm coaxial cable line of good quality terminated with a PL-259 coaxia

116.2 Displays All the DX-3 indicators are concentrated in a single, solid state, “moving LEDs” display (See drawing). The following values are displ

127 ELECTRICAL CONNECTIONS 7.1 Connections to Transceiver / Exciter Signal connections Before making any connections, ensure that DX-3 is not conn

13 Figure 3: TRANSFORMER AC INPUT CONNECTIONS 8 DX-3 DESCRIPTION 8.1 RF Section The RF section occupies the right hand side of the DX-3 (lookin

14The plate is connected to the RF network and to the choke supplying the 3400VDC voltage to the plate of the GU78B tube. 8.2 Mains transformer Th

15• Screen voltage regulator, with adjustable voltage and adjustable current limiting, for tube protection. • Overdrive protection and timer - bas

169 POWERING UP Before switching the power on, check all the necessary connections: Earth, Antenna, Transceiver, PTT, ALC. Make sure the 2 switches o

17• Repeat the above steps, while gradually increasing the input drive power, until the overdrive indicator just starts turning on. Now the DX-3 is

18NOTE: If the output is low (say, less than about 1500W), Ig2 will never show any screen current at all. Ig2 might even indicate a negative current,

1910.3 USING YOUR DX-3 While tuning and adjusting the amplifier, a CW mode is normally used. When these operations are finished, you can change to t

2DX-3, Serial No………… INITIAL SETTINGS FOR PLATE AND LOAD CAPACITORS TEST FREQUENCY BAND FACTORY SETTINGS 50 OHM LOAD USER SETTINGS ANTENNA P

20The Ig2 indicator should have three to four LED's flashing on at peak of modulation. This (combined with a correct plate tuning), indicates an

21full power for extended periods of time, with the fan not even going to high speed. The temperature cut-off happens when the tube reaches 150º Cels

22 14 GLOSSARY AC Alternating Current ALC Automatic Level Control AM Amplitude Modulation BALUN Balanced to Unbalanced Transformer BNC

2315 APPENDIX 1: SCHEMATIC DIAGRAMS 15.1 DX-3 Block Diagram POWER SUPPLY MODULE (See Schematic) DISPLAY MODULE & METERS (See Schematic) RF / TUB

2415.2 Circuit Diagram – HIGH VOLTAGE POWER SUPPLY NOTE: Two modules used in parallel GND 6A100 1R1000pF1000pF 6A100AC11000pF1000pFAC21000pF1000pF

25 15.3 Control Board and Adjustment Points COMPONENT SIDE VIEW The drawing below shows all the connections to the control board and the adjustment p

26 15.4 Circuit Diagram – AC INPUT AND WIRING DIAGRAM – Standard BlueABrownBottom viewBlue0V 4.7nF/250Vac/Y2EART

27 15.5 Circuit Diagram – AC INPUT AND WIRING DIAGRAM – U.S. Version MT2EARTH1MT2YellowBlueSWBrownMT1240VFEMALE

2815.6 Circuit Diagram – SOFT START (200 TO 240 V OPERATION) PHASEC62.2nFMT1R1100/2WR6270kD11N4007GATER4150/2WL

29 15.7 Circuit Diagram – QSK R133/2WR22.2kD21N4004Or P1D-1VD61N4004JP112RF DECK OUTE M T R O NRL1Jenings TJ1A-26SD51N4004RL2

3TABLE OF CONTENTS 1 GENERAL DESCRIPTION...

30 15.8 Circuit Diagram – RF MODULE NOTE: R1 changed to 680 ohm C31000pF/6kVC11000pF/6kVPLATE VOLTAGEC41000pF/6kVC112.2nFEBSCV325pFR2100R1100R475kM

31L63RL16YVR250kVR15kL76RC1 12. 2nFL56YL52YR1 22k2L38GC61nFR31k2R8100L55GR21k2R72k2L19RL33GX3 - 8Ig2-1U5LM3914594683271011121314151617181SIG I NMODER

3215.9 Circuit Diagram – CONTROL BOARD BR3LBA291C2210uFC2110nFX2.U10PC5211N4148D271N4148D28X8.BC557Q868RR182k2R17MPSA92Q23X7.22R71KR6BC547Q3MJE16002Q

3315.10 CONTROL BOARD – Component Legend (Silkscreen TOP) R8C5D191C311C27R70U3U5D12D17R7D5D6R39C17C13R85~~-+BR11C3~~-+BR21C111C4X8.SW11C6C14U2C2X1.X

34 Control Board – Solder Side Track work COPPER LAYER SOLDER SIDEAMPC V.3E

35 16 APPENDIX 2: WAVEFORMS 16.1 QSK (Optional module) Switching Fig. 4 No “Hot switching”: The output relay (Top trace) switches first,

36 17 APPENDIX 3: ADJUSTMENTS ADJUSTMENTS TO EMTRON “DX” AMPLIFIERS CAUTION Most of the following adjustments require the amplifier to be open and p

37With the amplifier running, wait the warm-up time. When READY, put OPR switch on and key the amplifier with NO INPUT DRIVE. Read the voltage at T

38threshold (higher sensitivity) can be used. A low threshold can make the EBS activate erratically, for example due to the ambient noise of in the r

39 Figure 6 BIASSWRSCREEN VOLTAGE SCREEN CURRENT LIMIT Ip PROTECTION EBS SENSITIVITY EBS OFF EBS ON

412.4 OVER-TEMPERATURE CUT-OFF...

40 Figure 7 17.2 DISPLAY BOARD ADJUSTMENTS The display board is pre-adjusted during testing. However, when installed in the amplifier, most adj

4117.2.4 FORWARD POWER (Adjustment: VR1, marked: RF F) On 20m, operate the amplifier at the full nominal power, as indicated by an external power me

4217.3 RF SENSOR ADJUSTMENT The amplifier is switched off for this adjustment. Check if adjustment is required as per following procedure, before ope

5DX-3 LINEAR AMPLIFIER Serial No ………… OPERATING MANUAL April 2005 CAUTION 1 GENERAL DESCRIPTION The Emtron DX-3 Linear Amplifier is a 3000

61.1 DX-3 – Internal View The main components of a DX-3 amplifier are shown in the picture below. Temperature Sensor TANK COIL 40 -160 m RF C

7 2 TECHNICAL SPECIFICATIONS FREQUENCY COVERAGE: Complete (manually tuned) coverage of the nine HF amateur bands: 1.800 – 1.900 MHz 3.500 – 4

8 Five single LED’s: • on air • ready • fault • overdrive warning • SWR cut-off indicator ALC: Negative going, adjustable output level. EBS:

9the 12-pin connector towards the front of the amplifier. Put the transformer in at a slight angle (about 10 degrees), so that it does not touch the