RF Linear Amplifier PCB Assembly Manual DX150C PCB Assembly Manual.pdf · RF Linear Amplifier PCB...

RF Linear Amplifier PCB Assembly Manual

SkyWave DX150 Revision-C

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www.telstar-electronics.com

http://www.telstar-electronics.com/



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Table of Contents

Introduction ...................................................................................................................................... 3

Required Parts List ............................................................................................................................. 4

Before You Start ................................................................................................................................ 6

Assembly Instructions ......................................................................................................................... 7

Step #1 - Spacer (SPACER1, SPACER2, SPACER3, SPACER4) ................................................................ 7

Step #2 - Transformer (T1, T2) ......................................................................................................... 9

T1 .............................................................................................................................................. 9

T2 ............................................................................................................................................ 11

Step #3 - Fixed Resistor (R1, R2, R3, R4, R5, R6, R7, R8, R10, R11, R13) ........................................... 13

Step #4 - Variable Resistor (VR1) .................................................................................................... 14

Step #5 – Diode (D1, D2, D4, D5, D6, D7) ....................................................................................... 16

Step #6 - Field Effect Transistor (Q2, Q3) ........................................................................................ 18

Step #7 – Bead & Air Inductor (L2, L3, L4) ....................................................................................... 20

Step #8 - Electrolytic Capacitor (C1, C2, C5, C8, C9) ......................................................................... 22

Step #9 - Ceramic & Mica Capacitor (C3, C6, C7, C10, C11, C12, C13, C14, C15, C16, C17, C18, C21, C22,

C23, C24, C25) ............................................................................................................................. 23

Step #10 - Fuse Holder (F1) ........................................................................................................... 25

Step #11 - Relay (RLY1) ................................................................................................................ 27

Step #12 - Toroid RF Choke (L1) ..................................................................................................... 29

Step #13 - Voltage Regulator (U1) .................................................................................................. 31

Step #14 - Field Effect Power Transistor (Q1) ................................................................................... 33

Step #15 – Field Effect RF Power Transistor (Q4, Q5) ........................................................................ 35

Step #16 – Coaxial Cable ............................................................................................................... 37

Step #17 - Switch, LED, and Power Wiring ....................................................................................... 38

PCB Mounting to Heat Sink ................................................................................................................ 39

Bias Adjustment ............................................................................................................................... 42

Amplifier Operation .......................................................................................................................... 43

Connecting the Amplifier ................................................................................................................ 43

Transmitting ................................................................................................................................. 43

Troubleshooting ............................................................................................................................... 44

Specifications .................................................................................................................................. 45

RF Performance ............................................................................................................................... 46




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Introduction

Congratulations on your purchase of the new SkyWave DX150 RF Amplifier PCB. This PCB is a result of the

highest quality engineering to provide excellent performance and reliability.

Listed below are some of the key features:

+13.8VDC Operation

All Mode (AM, FM, SSB)

10-Meter Amateur Band Coverage

MOSFET (FQP13N10) Push-Pull Configuration

Low Current Requirement – Can Plug into Most Vehicle Cigarette Lighter Receptacles

Class-AB Bias

High Output Power / Low Harmonic Content

Carrier Operated or Manual* Transmit / Receive Switching

Continuous Reverse Voltage Protection without Damage to Amplifier or Fuse

Thermal Shutdown

Fuse Protected

Selectable SSB Delay

Power and Transmit Indicators

Low Stand-By Power Consumption

Teflon® Insulated Wire

Premium Quality FR-4 Grade Printed Circuit Board w/ Solder Mask & Silk Screen

High Reliability Design

We have developed a logical step-by-step procedure that we hope will make your assembling experience

efficient & pleasurable…

* Contact Telstar Electronics for details on using this feature.




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Required Parts List

Quantity Description Reference

24” Cable, Coaxial, RG174A/U Type, 52-Ohm RF IN, RF OUT

7 Capacitor, 0.01uF, 100V, 20%, Z5U, Radial (LS=0.197") C7, C11, C13, C15, C17,

C18, C24

3 Capacitor, 0.1uF, 50V, 10%, X7R, Radial (LS=0.197") C6, C10, C14

1 Capacitor, 1000pF, 500V, 10%, X7R, Radial (LS=0.197") C12

1 Capacitor, 100uF, 25V, 20%, 1K Hours, 105C, 5x11mm, Radial

(LS=0.079”) C9

3 Capacitor, 10uF, 25V, 20%, Radial (LS=0.079") C1, C2, C5

1 Capacitor, 1uF, 50V, 20%, Radial (LS=0.079") C8

3 Capacitor, Dipped Mica, 330pF, 1000V, 5%, Radial (LS=0.232") C16, C23, C25

2 Capacitor, Dipped Mica, 47pF, 500V, 5%, Radial (LS=0.232") C3, C22

1 Capacitor, Dipped Mica, 560pF, 500V, 5%, Radial (LS=0.344") C21

2 Diode, High Speed Signal, 1N914, DO-35, Axial D1, D2

1 Fuse, ATC, 15A F1

1 Holder, Fuse, ATC Type, TH F1

2 Inductor, RF Choke, 15uH, Wound Bead, Axial L2, L3

1 Inductor, Air, 12T, #18 Magnet, 0.312" Diameter, Close Wound L4

3 Insulator, Phase Change, TO-220 INSUL1, INSUL2, INSUL3

(Q1, Q4, Q5)

1 PCB, SkyWave DX150 Revision-C (3.8” x 5.4”) N/A

1 Potentiometer, 1K, 0.1W, V-Adjust, TH VR1

1 Regulator, Voltage, 5V, 1A, TO-220 U1

1 Relay, DPDT, 5V, 8A, DIP RLY1

1 Resistor, 1.5K, 0.25W, 5%, Axial R2

1 Resistor, 100, 0.25W, 5%, Axial R5

2 Resistor, 100, Metal Oxide, 2W, 5%, Axial R7, R8

1 Resistor, 100K, 0.25W, 5%, Axial R3

2 Resistor, 10K, 0.25W, 5%, Axial R4, R6

1 Resistor, 3.3K, 0.25W, 5%, Axial R11

2 Resistor, 330, 0.25W, 5%, Axial R1, R13

1 Resistor, 47K, 0.25W, 5%, Axial R10




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Quantity Description Reference

4 Screw, Machine, Philips Pan Head, 4-40, 1/4", Stainless Steel TO-220 to Heat Sink.

4 Screw, Machine, Philips Pan Head, 4-40, 5/16", Stainless Steel PCB to Heat Sink.

4 Spacer, Round, 0.250"D, 0.125"ID, 0.100" Thick SPACER1, SPACER2,

SPACER3, SPACER4

1 Toroid, 0.825"OD, 0.520"ID, 0.250"W, #43 Material L1

1 Transformer, RF Input, #43 Material T1

1 Transformer, RF Output, #43 Material T2

2 Transistor, FET, N-Channel, Switching, 100V, 12.8A, 65W, TO-220 Q4, Q5

1 Transistor, FET, N-Channel, 2N7000, TO-92 Q3

1 Transistor, FET, P-Channel, TP0606, TO-92 Q2

1 Transistor, FET, P-Channel, SUP75P03-07, TO-220 Q1

4 TVS, Uni-Directional, DO-15 D4, D5, D6, D7

3 Washer, Shoulder, Black Plastic Insulating, TO-220 WASHER1, WASHER2,

WASHER3 (Q1, Q4, Q5)

14” Wire, #16, Teflon, Red, Stranded L1

21” Wire, #20, Teflon, Orange, Stranded T1, T2 (T1=6", T2=12")

24” Wire, #22, Teflon, Blue, Stranded LED1, SW1

24” Wire, #22, Teflon, Green, Stranded LED1, SW1

24” Wire, #22, Teflon, Purple, Stranded LED2, SW2

24” Wire, #22, Teflon, Yellow, Stranded LED2, SW2

24” Wire, Zip Cord, #12, Red/Black 13.8V, GND




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Before You Start

This document assumes a basic understanding of electronics, soldering, and operation of hand tools. In

addition to basic hand tools, the following items will be required for proper assembly.

PCB Assembly:

Soldering Iron†

Electronic Solder‡

7/64” Drill Bit (Alignment of SPACER1, SPACER2, SPACER3, SPACER4)

1/4” Drill Bit (Lead Forming of U1, Q1, Q4, Q5)

Needle Nose Pliers

Diagonal Cutting Pliers

Wire Stripper

PCB Assembly to Heat Sink:

Heat Sink (See Page 39 for Requirements)

Power Drill

#4-40 Tap (Mounting Holes in Heat Sink)

#42 Drill Bit (Mounting Holes in Heat Sink)

Masking Tape

Transfer Punch

Bias Adjustment:

13.8VDC Power Supply (1 Ampere Minimum)

Ammeter (Capable of Measuring 200mA)

Several Jumper Wires w/ Alligator Clips

Please take a few minutes before you begin assembling to review the entire assembly &

adjustment procedure.

A few things to remember during the assembly:

Several components in this design are sensitive to static electricity. Precautions should be taken to

avoid static buildup during assembly by using a grounded workstation mat and wrist band.

References are made to the top and bottom side of the PCB. The top side contains the printed

reference designators and component outlines.

If at any time, you’re unsure how to perform an assembly step or have a question, email us for

assistance at [email protected]

† 35W-65W recommended. Temperature controlled soldering equipment is always preferred. ‡ Solder recommendation is Kester 331. This solder has a flux that can be washed off with warm tap-water.




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Assembly Instructions

Step #1 - Spacer (SPACER1, SPACER2, SPACER3, SPACER4)

Locate the positions on the bottom of the PCB where the spacers will be attached. (Figure 1)

With the aid of a 7/64” drill bit, position the drill bit shank§ through a spacer and through the hole

on the PCB. The drill bit will aid in centering the spacer on the PCB hole during the soldering

process. (Figure 2)

IMPORTANT - MAKE CERTAIN THE SPACERS ARE FLAT AGAINST THE BOTTOM SIDE OF THE PCB

BEFORE SOLDERING INTO POSITION. USE A MINIMAL AMOUNT OF SOLDER

MAKING CERTAIN NOT TO OBSTRUCT THE INNER HOLE.

Solder the spacers in position.

Figure 1

§ The drill bit shank is the solid portion that doesn’t contain the spiral cutting flutes.

SPACER

SPACER

SPACER

SPACER




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Details of spacer installation.

Figure 2




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Step #2 - Transformer (T1, T2)

T1

IMPORTANT - TRANSFORMERS ARE POLARIZED AND MUST BE INSTALLED IN THE PROPER

ORIENTATION.

Position T1 on the PCB noting the proper transformer polarity. (Figure 3)

Solder all three pads on T1 for proper attachment to PCB.

Strip the insulation from one end of the 6” AWG#20 wire. Solder the stripped end to the START

pad. (Figure 3)

Wind the unsoldered end of the wire three complete turns through the tubes of the transformer in

a loop type fashion. (Figure 4 and Figure 5)

Cut and strip the wire, making it just long enough to reach to the FINISH pad. (Figure 3)

Solder the wire to FINISH pad. (Figure 3)

Figure 3

T1

START

FINISH




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Details of T1 installation.

Figure 4

Figure 5




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T2

IMPORTANT - TRANSFORMERS ARE POLARIZED AND MUST BE INSTALLED IN THE PROPER

ORIENTATION.

Position T2 on the PCB noting the proper transformer polarity. (Figure 6)

Solder all three pads on T2 for proper attachment to PCB.

Strip the insulation from one end of the 12” AWG#20 wire. Solder the stripped end to the START

pad. (Figure 6)

Wind the unsoldered end of the wire three complete turns through the tubes of the transformer in

a loop type fashion. (Figure 7 and Figure 8)

Cut and strip the wire, making it just long enough to reach to the FINISH pad. (Figure 6)

Solder the wire to FINISH pad. (Figure 6)

Figure 6

T2

FINISH

START




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Details of T2 installation.

Figure 7

Figure 8




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Step #3 - Fixed Resistor (R1, R2, R3, R4, R5, R6, R7, R8, R10, R11, R13)

IMPORTANT - FIXED RESISTORS HAVE NO POLARITY AND CAN BE INSTALLED IN EITHER

DIRECTION. MAKE CERTAIN THE RESISTORS ARE FULLY SEATED IN THE PCB

BEFORE SOLDERING.

Install resistors into the PCB at the proper designated positions. (Figure 9)

Solder all resistors in position.

Cut the excess lead length on the bottom of the PCB.

Figure 9




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Step #4 - Variable Resistor (VR1)

IMPORTANT - VARIABLE RESISTORS ARE POLARIZED AND MUST BE INSTALLED IN THE PROPER

ORIENTATION. MAKE CERTAIN THE RESISTOR IS FULLY SEATED IN THE PCB

BEFORE SOLDERING.

Insert VR1 into PCB. (Figure 10 and Figure 11)

Solder variable resistor in position.


Figure 10




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Details of VR1 installation.

Figure 11




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Step #5 – Diode (D1, D2, D4, D5, D6, D7)

IMPORTANT - DIODES ARE POLARIZED AND MUST BE INSTALLED IN THE PROPER

ORIENTATION. THE WHITE BAND INDICATED ON THE PCB INDICATES THE

CATHODE. THIS POLARITY BAND IS ALSO PRESENT ON THE DIODE ITSELF. MAKE

CERTAIN THE DIODES ARE FULLY SEATED IN THE PCB BEFORE SOLDERING.

Insert D1 and D2 into PCB at the proper locations. (Figure 12)

Solder diodes in position.


Figure 12




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IMPORTANT - DIODES ARE POLARIZED AND MUST BE INSTALLED IN THE PROPER

ORIENTATION. THE WHITE BAND INDICATED ON THE PCB INDICATES THE

CATHODE. THIS POLARITY BAND IS ALSO PRESENT ON THE DIODE ITSELF. MAKE

CERTAIN THE DIODES ARE FULLY SEATED IN THE PCB BEFORE SOLDERING.

Insert D4, D5, D6, and D7 into PCB at the proper locations. (Figure 13)

Solder diodes in position.


Figure 13




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Step #6 - Field Effect Transistor (Q2, Q3)

IMPORTANT - TRANSISTORS ARE POLARIZED AND MUST BE INSTALLED IN THE PROPER

ORIENTATION. USE THE OUTLINE ON THE PCB AS A GUIDE TO INSTALL THE

TRANSISTORS WITH THE FLAT SIDE AS SHOWN.

Insert Q2 and Q3 into the PCB at the proper location. (Figure 14 and Figure 15)

Solder transistors in position.


Figure 14

FLAT

FLAT




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Details of Q2 and Q3 installation.

Figure 15




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Step #7 – Bead & Air Inductor (L2, L3, L4)

IMPORTANT - INDUCTORS HAVE NO POLARITY SO THEY CAN BE INSTALLED IN EITHER

DIRECTION. MAKE CERTAIN L2 AND L3 ARE FULLY SEATED IN THE PCB BEFORE

SOLDERING.

Insert L2 and L3 into the PCB at the proper location. (Figure 16)

Solder both inductors in position.


Apply solder to the PCB pads of L4.

Apply solder to the ends of L4. It may be necessary to rub the soldering iron on the ends while

applying solder, to get the solder to flow.

Solder L4 in position, holding it in place using a needle nose pliers. (Figure 17)

Figure 16




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Details of L2, L3, and L4 installation.

Figure 17




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Step #8 - Electrolytic Capacitor (C1, C2, C5, C8, C9)

IMPORTANT - ELECTROLYTIC CAPACITORS ARE POLARIZED AND MUST BE INSTALLED IN THE

PROPER ORIENTATION. THESE CAPACITORS HAVE MARKINGS INDICATING THE -

(NEGATIVE) TERMINAL. THE PCB INDICATES CAPACITOR POLARITY BY

DISPLAYING A + (POSITIVE) SYMBOL CLOSEST TO THE POSITIVE TERMINAL OF

THE CAPACITOR. MAKE CERTAIN THE CAPACITORS ARE FULLY SEATED IN THE

PCB BEFORE SOLDERING.

Insert capacitors into the PCB at the proper designated positions. (Figure 18)

Solder all capacitors in position.


Figure 18




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Step #9 - Ceramic & Mica Capacitor (C3, C6, C7, C10, C11, C12, C13, C14, C15, C16,

C17, C18, C21, C22, C23, C24, C25)

IMPORTANT - CERAMIC AND SILVERED MICA CAPACITORS HAVE NO POLARITY AND CAN BE

INSTALLED IN EITHER DIRECTION.

Insert each capacitor into the proper location. (Figure 19 and Figure 20)

Solder all capacitors in position.


Figure 19

C25 C21




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Details of ceramic & mica capacitor installation.

Figure 20




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Step #10 - Fuse Holder (F1)

IMPORTANT - FUSE HOLDERS HAVE NO POLARITY AND CAN BE INSTALLED IN EITHER

DIRECTION. MAKE CERTAIN THE FUSE HOLDER IS FULLY SEATED IN THE PCB

BEFORE SOLDERING.

Press the fuse holder into the top of the PCB. (Figure 21 and Figure 22)

Solder the fuse holder into position.


Figure 21




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Details of F1 fuse holder installation.

Figure 22




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Step #11 - Relay (RLY1)

IMPORTANT - RELAYS ARE POLARIZED AND MUST BE INSTALLED IN THE PROPER

ORIENTATION. MAKE CERTAIN THE RELAY IS FULLY SEATED IN THE PCB BEFORE

SOLDERING.

Install the relay into the top of the PCB. (Figure 23 and Figure 24)

Solder relay in position.


Figure 23




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Details of RLY1 relay installation.

Figure 24




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Step #12 - Toroid RF Choke (L1)

IMPORTANT - INDUCTORS HAVE NO POLARITY AND CAN BE INSTALLED IN EITHER DIRECTION.

THIS INDUCTOR WILL REQUIRE WINDING THE SUPPLIED 14” LENGTH OF AWG

#16 RED WIRE ONTO THE TOROID FERRITE CORE.

Wind ten complete turns through the supplied core.

Cut and strip wire ends.

Solder L1 to top of PCB. (Figure 25 and Figure 26)

Figure 25

L1




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Details of L1 installation.

Figure 26




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Step #13 - Voltage Regulator (U1)

IMPORTANT - VOLTAGE REGULATORS ARE POLARIZED, AND MUST BE INSTALLED IN THE

PROPER ORIENTATION.

Take the transistors and form the leads around a 1/4" drill bit so the leads are bent at a 90-degree

angle. (Figure 28)

Insert regulator from the bottom of the PCB so the leads protrude upward through the holes. (Figure

27)

Place the PCB on a flat surface with the regulator in position and solder from the top of the PCB. (Figure 29)

Cut the excess lead length on the top of the PCB.

Figure 27




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Details of lead forming.

Figure 28

Details of U1 installation.

Figure 29




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Step #14 - Field Effect Power Transistor (Q1)


ORIENTATION.

Take the transistor and form the leads around a 1/4" drill bit so the leads are bent at a 90-degree

angle. (Figure 31)

Insert transistor from the bottom of the PCB so the leads protrude upward through the holes. (Figure 30)

Place the PCB on a flat surface with the transistors in position and solder from the top of the PCB. (Figure 32)


Figure 30




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Figure 31

Details of Q1 installation.

Figure 32




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Step #15 – Field Effect RF Power Transistor (Q4, Q5)


ORIENTATION.

Take the transistors and form the leads around a 1/4" drill bit so the leads are bent at a 90-degree

angle. (Figure 34)

Insert transistors from the bottom of the PCB so the leads protrude upward through the holes. (Figure 33)

Place the PCB on a flat surface with the transistors in position and solder from the top of the PCB. (Figure 35)


Figure 33




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Figure 34

Details of Q4 and Q5 installation.

Figure 35




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Step #16 – Coaxial Cable

IMPORTANT - COAXIAL CABLE IS POLARIZED AND MUST BE INSTALLED IN THE PROPER

ORIENTATION. THE BRAIDED PORTION OF THE CABLE IS ALWAYS ATTACHED TO

GROUND (GND).

Solder the coaxial cables at the proper designated positions. (Figure 36)

Figure 36




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Step #17 - Switch, LED, and Power Wiring

The SkyWave DX150 has been designed to accommodate two switches** and two LED†† indicators. These

switches and indicators have the following functions:

SW1 (ON/OFF) – Amplifier Main Power

LED1 – Main Power LED Indicator

SW2 (SSB DELAY) – SSB Delay Enable

LED2 – Transmit LED Indicator

Solder the AWG#22 wires at the proper designated positions. (Figure 37)

Solder the AWG#12 power cord into position with the red wire to 13.8V and the black to GND. (Figure 37)

Details of switch, LED, and power wiring.

Figure 37

** Switches should be SPST type capable of 100mA@25V minimum. †† LEDs can be any color/size and should be rated for an operating forward current of 20mA. The PCB has been marked with the “+” for orientation

connection purposes.




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PCB Mounting to Heat Sink

IMPORTANT - NOW THAT THE AMPLIFIER PCB HAS BEEN FULLY ASSEMBLED, IT MUST BE

MOUNTED TO AN ADEQUATE HEAT SINK BEFORE THE BIAS ADJUSTMENT CAN BE

PERFORMED. A HEAT SINK WITH A MAXIMUM THERMAL RESISTANCE OF 1.5

DEGREE CENTIGRADE/WATT IS RECOMMENDED FOR CONVECTION

APPLICATIONS‡‡.

Place the completed PCB on the heat sink. Use masking tape or equivalent to hold the PCB still

during the marking process. Using a transfer punch§§, carefully mark the center of the four PCB

mounting holes that contain the spacers, the two RF transistor mounting holes, and the two

mounting tab holes at the edge of the PCB. (Figure 38)

Figure 38

‡‡ There are several internet sites that sell extruded aluminum heat sinks designed for RF power amplifiers. Several are listed below. Telstar Electronics

takes no responsibility for the content of the links and does not endorse any specific product or service.

Communication Concepts – www.communication-concepts.com

Heatsink USA – www.heatsinkusa.com §§ A transfer punch is a punch of a specific outer diameter that is non-tapered and extends the entire length of the punch (except for the tip). It is used to

tightly fit the tolerances of an existing hole and, when struck, precisely transfer the center of that hole to another surface.


http://www.communication-concepts.com/

http://heatsinkusa.com/



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Remove the tape and PCB from the heat sink. Use an automatic center punch to enhance the

marked centers prior to drilling. Use a #42 (0.0935”) drill bit to drill all marked centers.

Use a #4-40 tap to thread all eight drilled holes.

Position insulators (INSUL1, INSUL2, INSUL3) on the heat sink so that they will make proper

contact with the metal tabs of Q1, Q4, Q5 and will align properly with the tapped mounting holes. (Figure 39)

Hover the PCB over the mounting holes drilled in the heat sink. Lower the PCB straight down onto

the sink to avoid sliding the insulators.

Install loosely four 5/16” #4-40 machine screws in the four PCB mounting that have the metal

spacers below the PCB.

Figure 39

Install loosely one 1/4" long #4-40 machine screw in the metal tab of U1.




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IMPORTANT - PLASTIC INSULATING WASHERS ARE NOT SYMMETRICAL, AND MUST BE

ORIENTED AS SHOWN BELOW. (FIGURE 40)

Install three plastic insulating washers (WASHER1, WASHER2, WASHER3) on three 1/4"long #4-40

machine screws and install the screws loosely for Q1, Q4, and Q5. (Figure 40)

Figure 40

IMPORTANT - DON’T OVER-TIGHTEN SCREWS THAT CONTAIN THE PLASTIC INSULATING

WASHERS.

Tighten all eight 4-40 screws (6 in/lbs.) starting with Q4 and Q5.




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Bias Adjustment

The SkyWave DX150 amplifier has been designed to operate with class-AB biasing.

IMPORTANT – TO KEEP OUTPUT HARMONICS AT SPECIFIED LEVELS, THE BIAS MUST BE

ADJUSTED PRIOR TO THE AMPLIFIER BEING PUT INTO SERVICE.

Solder the two wires from SW1 (ON/OFF) together.

Solder the two wires from SW2 (SSB DELAY) together.

Insert 15A fuse (F1).

Place an ammeter across jumper (JMP1) terminals.

Turn VR1 (BIAS) fully counter-clockwise.

Connect the 13.8VDC power cord to a power supply.

Connect RF IN (center conductor of coaxial cable) to 13.8VDC. Ground of coaxial cable remains

disconnected.

Turn power supply on and set output at 13.8VDC.

Adjust VR1 (BIAS) slowly clockwise to obtain 200mA (+/-25mA) on the ammeter.

Disconnect all connections to power supply and ammeter.

IMPORTANT - THE TWO PADS ON THE JUMPER MUST BE SHORTED TOGETHER FOR THE

AMPLIFIER TO OPERATE PROPERLY.

Apply a liberal amount of solder to the jumper (JMP1) pads so a solder bridge is formed.




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Amplifier Operation

Connecting the Amplifier

IMPORTANT - THE AMPLIFIER REQUIRES A DC POWER SOURCE CAPABLE OF 13.8V@15A TO

ACHIEVE MAXIMUM POWER OUTPUT. IN THE FINAL APPLICATION, KEEP THE

POWER CABLE AS SHORT AS POSSIBLE TO OPTIMIZE AMPLIFIER PERFORMANCE.

Attach the power cable to a DC source.

IMPORTANT - MAKE CERTAIN THAT THE ANTENNA/FEEDLINE SWR IS 1.5:1 OR LOWER. A HIGH

SWR WILL CAUSE EXCESSIVE OUTPUT TRANSISTOR HEATING THAT COULD

RESULT IN PREMATURE DEVICE FAILURE.

Hook the amplifier RF IN via a 50-Ohm coaxial cable to the driving transmitter.

Hook the amplifier RF OUT via a 50-Ohm coaxial cable to the transmitting antenna.

Install a SPST switch to the wiring coming from SW1 (POWER).

Install a SPST switch to the wiring coming from SW2 (SSB).

Install an LED to the wiring coming from LED1 (POWER).

Install an LED to the wiring coming from LED2 (XMIT).

Transmitting

Set SW1 (POWER) switch to the “ON” position.

Set SW2 (SSB) switch to the “ON” position if transmitter is in SSB mode.

The amplifier is now ready for operation.




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Troubleshooting

Problem Possible Cause Possible Solution

Amplifier doesn’t operate

(Power switch “ON” but power

indicator not lit)

Power source not

connected.

Check connection to power

source.

Fuse missing or blown. Check F1.

Faulty wiring from SW1

switch to circuit board.

Check wiring from SW1 switch

to circuit board.

Amplifier doesn’t operate

(Power switch on and power

indicator lit)

Insufficient or no RF drive. Check transmitter and coaxial

cable to input of amplifier.

Relay engages on transmit but

amplifier has no output power. J1 open. Check that J1 is shorted.

Relay chatters during SSB

operation.

SW2 switch not in SSB

position.

Move SW2 switch to proper

position.

Faulty wiring from SW2

switch to circuit board.

Check wiring from SW2 switch

to circuit board.

Relay chatters during AM/FM

operation. Insufficient drive power. Increase drive power.

Amplifier keeps blowing fuse.

Plastic insulating washers

(WASHER1, WASHER2,

WASHER3) improperly

installed.

Check plastic insulating

washers on Q1, Q4, Q5.

Insulators (INSUL1,

INSUL2, INSUL3)

improperly installed.

Check insulators on Q1, Q4,

Q5.




Last Revised - 12/29/2018 2:30 AM

of 46


Specifications

Parameter Conditions/Notes Value

Operating Modes - AM, FM, SSB

Voltage Requirements Typical +13.8VDC

Maximum +16VDC

DC Current Maximum 12A

RF Input Power

Minimum 500mW (AM, FM)

Maximum 10W-RMS (AM, FM)

40W-PEP (SSB)

RF Power Output @1dB Compression 70W-RMS (AM/FM)

130W-PEP (SSB)

2nd Harmonic 25W CW@28MHz Typical -46dBc***

3rd Harmonic 25W CW@28MHz Typical -30dBc

Input / Output Impedance††† Typical 50-Ohms

Input SWR‡‡‡ Typical 1.2:1

Power Gain Typical @28MHz 8dB

Bandwidth 26-30MHz 0.5dB Gain Flatness

Class-AB Bias Current +25◦C Heat Sink Temperature 200mA +/-25mA

Fuse ATO - Automotive Type 15A

SSB Relay Dropout Delay Typical 1.0 Second

Stand-By Power Typical 75mW

Reverse Voltage Protection No Damage to Amplifier or

Fuse Continuous

Thermal Shutdown Heat Sink Temperature ~120˚C

PCB Solder Mask & Silkscreen Premium FR4 Material

*** Decibels below carrier. ††† An antenna system with an SWR of 1.5:1 or less is critical for proper amplifier operation.

‡‡‡ Standing Wave Ratio.




Last Revised - 12/29/2018 2:30 AM

of 46


RF Performance

8

16

24

32

40

48

56

64

7277

80

0

10

20

30

40

50

60

70

80

90

0 1 2 3 4 5 6 7 8 9 10 11 12

OU

TPU

T (W

ATT

S R

MS)

INPUT (WATTS RMS)

AM/FM Power Output @ 14.2V/28MHz

15

30

45

60

75

90

105

120

135145

150

0

25

50

75

100

125

150

175

0 5 10 15 20 25 30 35

OU

TPU

T (W

ATT

S P

EP)

INPUT (WATTS PEP)

SSB Power Output @ 14.2V/28MHz


RF Linear Amplifier PCB Assembly Manual DX150C PCB Assembly Manual.pdf · RF Linear Amplifier PCB...

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