Small Wonder Labs PSK-40, Instructions Manual

Page 1: ...te This version of the printed circuit board features all through hole capacitors and only one SMT part U8 Please refer to the enclosed sketch for placement of 01 disk capacitors and IC sockets for U3 and U7 and install those components during assembly The parts list has been revised to reflect this change TABLE OF CONTENTS First Things First 2 Materials 3 Parts List 4 Theory of Operation 6 Schema...

Page 2: ...r the ARRL Handbook will help If you re not sure verify the resistor values with a multimeter before installing For what it s worth roughly 8 of the male population is red green color blind If you re one of these you should be verifying all resistors with a multimeter before installing them The PSK 40 board is double sided and all holes on the board are plated through This means that you do not ne...

Page 3: ...robe and the board trace simultaneously until the tool pushes through Lacking either of these tools a round wooden toothpick works well also WINDING TOROIDS Count as you go Draw each turn snug against the core to ensure a trim and tight winding Double check the turns count when you re finished Use your fingernail or small screwdriver to bump over each turn as you count this is considerably easier ...

Page 4: ...e failure Extra information on components There s often extraneous information marked on components Examining a sample IC I find MC1458P1 KKJK 8949 You care only about the 1458 or other markings I ve specified If I ve specified a capacitor 104 and you find the correct number of parts but marked 104M for instance those are them Dr Suess called it Calculatus Eliminatus a wise man indeed IF Transform...

Page 5: ...1 J310 JFET plastic pkg 1 Q2 2N2222A NPN transistor metal pkg 1 Q3 2N3906 PNP transistor plastic pkg 2 Q4 Q12 2N7000 MOSFET transistor plastic pkg 4 Q5 Q8 2N4401 NPN transistor plastic pkg 1 Q9 MPSH10 NPN transistor plastic pkg 1 Q10 2N2219A NPN transistor metal pkg 1 Q11 2SC2078 NPN RF power transistor TO 220 pkg C2078 3 R54 R56 1 5 ohm Resistor 1 4W 5 Brn grn gold gold 5 R7 R17 R47 R51 R52 10 oh...

Page 6: ...ciated components The output of this preamp is slug tuned via inductor L3 Diode ring Mixer U1 is fed with a 11 98 MHz Local Oscillator LO signal and converts the incoming 7 MHz received signal to the 4 91 MHz Intermediate Frequency IF Q2 and associated circuitry are a mixer post amp and provide both gain and a termination for the mixer The post amp is followed by a 6 dB resistive attenuator with t...

Page 7: ... plainly audible through the receiver This situation would lead to soundcard feedback distortion on receive without the presence of this muting function Q6 is an emitter follower which provide a 51 ohm source termination for diode ring mixer U6 U6 is driven by a signal from the 4 91 MHz LO Colpitts oscillator Q7 and associated components The output of mixer U6 is a suppressed carrier double sideba...

Page 8: ...49 L8 L9 L10 C118 R51 Q10 C38 R52 R53 R54 56 D11 C119 Q11 T2 D12 C121 C120 D10 C39 C40 C41 C42 C43 L11 L12 L13 R57 D13 D14 C122 TP2 J5 Vr Vr Vr Vr Vr V Vr Vsw Vsw Vsw J6 01 ANT 2 2K 330 330 680 680 220 uF 1 1 220 1 5 3 pl 1 51 10 1 10 4 7K 1K 2 2 uH 2 2 uH 1000 270 10 4 20 22K 47K 68 2 pl 1K 6 8 uH 150 01 78L08 IN 01 1 uF 10K 2 2K 100 470 22K 220 10 uF C23 51 47 uF 2 3 1 2 2 XMTR AF In 4 51 1 5K R...

Page 9: ... 10K 22K 01 22K 10K C110 J4 C 4 7K R32 Q3 C124 2N3906 01 4 7K V U4 B J1 AF Out C16 01 C18 Vr D15 C19 1 C106 D5 D6 C20 3 3 3 2 1 R21 1M V R22 R23 33K 10K C13 220 T1 R24 2 2K C109 01 2 8 1 5 3 7 MC1350 U2 100 R13 V U4 A LM1458 E V C105 01 6 4 2 2K 01 R12 C104 C12 4 915 MHz Y1 Y2 Y3 Y4 C9 C10 C11 C8 C12 22 pF C7 C8 68 18 uH L5 R10 R9 R11 150 680 680 01 C6 R7 R8 C103 Q2 L4 22 uH 10 100 01 R4 V C102 01...

Page 10: ...3 R34 R35 10K 220 470 R40 TEST C25 Y7 R41 R42 51 1 5K 22 C26 C27 22 22 C28 22 22 C29 Y8 Y9 Y10 C109 Y1 Y2 Y3 Y4 R12 C104 C9 C10 C11 C12 22 22 22 22 2 2K C13 C108 R18 220 01 10K 01 C115 U7 01 22 68 C7 C8 R11 R10 R9 680 680 150 C114 C124 01 D9 D13 C1 47 D1 D4 L2 L1 10 uH 2 2 uH 220 uF C120 U9 Q3 C44 Y5 C48 Y6 11 981 C112 01 10K R25 Q7 TP2 J4 L5 18 uH C3 C5 01 270 01 01 1000 C101 C102 C4 R3 Q1 2 2K 0...

Page 11: ...t points from the top side of the board Orientation of color bands on resistors and other nonpolar devices is not critical Installing IC sockets The notch or dot at one end should be oriented as shown in the pictorial drawings Doublecheck orientation before soldering A suggestion solder down two opposite corners of each socket and then go back and press a fingertip on the socket from underneath wh...

Page 12: ...part Observe the polarity marking on the device the dark bar down one side of the part denotes the negative lead Note that the longer of the two capacitor leads is Install diodes D16 and D17 1N4148s below J4 Match the installation polarity as shown on the silkscreen Install an 8 pin IC socket at U5 Match the notch orientation as shown on the silkscreen Install resistor R25 10K brn blk org Install ...

Page 13: ... blk orange Install C16 01 uF disk cap Install diodes D5 and D6 1N4148 Observe the installation polarity as shown on the silkscreen Install electrolytic cap C20 3 3 uF Observe the installation polarity as shown on the silkscreen Install R21 1 Megohm brn blk green Install R23 10K brn blk orange Install R22 33K orange org org Install R18 10K brn blk orange Install C13 220 pF disk cap Install D15 1N4...

Page 14: ...gently on the component to lift it slightly Install R59 47K yellow violet org Install R58 22K red red org Install R60 1K brown blk red Install disk caps C45 and C46 68 pF Install monolithic cap C47 150 pF Note these components are somewhat fragile To spread the lead spacing to match the 0 2 5mm spacing on the pads grasp the capacitor body between thumb and forefinger Spread the wire leads apart ou...

Page 15: ...on cautions Install C7 68 pF disk cap Install C8 through C12 22 pF ceramic disk caps Install four of the 4 915 MHz crystals at Y1 Y4 Install R10 150Ω brown green brown Install R9 and R11 680Ω blue gry brown Install L4 22 uH RF choke red red black Install R5 1K brn black red Install R6 470Ω yellow violet brown Install R7 10Ω brn black black Install R8 100Ω brn black brown Install Q2 2N2222 small me...

Page 16: ...uH RF choke red red gold Install C1 47 pF disk cap Install transistor Q1 J309 J310 from antistatic bag Match the orientation of the flat side of the component to that of the silkscreen Install Mixer U1 MCL TUF 1 or TFM 2 from antistatic bag Be sure that the part labeling is oriented as shown on the figure on this page and that the part correctly overlaps the silkscreened outline on the board Cauti...

Page 17: ...e these locations Install C24 47 uF electrolytic cap Observe the installation polarity as shown on the silkscreen Install Q4 2N7000 from antistatic bag Match the orientation of the flat side of the component to that of the silkscreen This part is static sensitive Install Q5 and Q6 2N4401 from antistatic bag Match the orientation of the flat side of the components to that of the silkscreen Install ...

Page 18: ...3 1K brown blk red Install D9 1N5236 from Zeners envelope Match the orientation of the banded end of the component to that of the silkscreen Install R44 220Ω red red brown Install R45 22K red red orange Install R46 100Ω brn black brown Install Q9 MPSH10 from antistatic bag Match the orientation of the flat side of the component to that of the silkscreen C25 Y7 R42 1 5K 22 C26 C27 22 22 C28 22 22 C...

Page 19: ...component Note its placement carefully with respect to nearby silkscreened component outlines before installing and soldering Install R51 and R52 10Ω brown blk black Install C118 and C119 1 uF monolithic cap 104 Install D10 1N4148 Match the orientation of the banded end of the diode with that of the silkscreen Install D11 1N4001 power diode Observe the installation polarity as shown on the silkscr...

Page 20: ...upplied with the kit Nick the insulation jacket slightly to expose one or more individual wires pull these out of the jacket discard the jacket Select any 2 of the 4 wires and pass both through the hole in the toroid Wrap this wire pair snugly around the toroid for one complete turn It should look like this Proceed to thread the wire pair through the hole again and draw it snug Repeat this threadi...

Page 21: ...place with a nylon nut Make sure that the heat sink is aligned parallel with the board before tightening the nut Tighten cautiously the nylon nut threads will strip at the torque typically used for steel hardware Solder Q11 s leads into place Caution do not substitute a metallic nut here You may find it easier to pin the transistor and heat sink together with the machine screw using a fingertip to...

Page 22: ...rry enclosures offered by a number of companies There s no minimum order and they can be reached at 800 524 6464 for a catalog Ten Tec also offers a complete line of enclosures and they support small orders as well Call 800 231 8842 for a free brochure The enclosure option for this transceiver is a Lansing Micropak CT1 series enclosure with a companion custom punched end panel The board size is ta...

Page 23: ...T to the PSK 40 s J3 connector with a 3 5mm 1 8 3 conductor cable Connect your computer speaker cable to the PSK 40 s J2 connector J2 and J3 are in parallel and permit use of the soundcard for other applications without repeated plugging and unplugging of cables Using a small slot screwdriver adjust transformer T1 for maximum audio to the speakers Note If you have an antenna connected already AGC ...

Page 24: ...Connect the multimeter return lead to board ground to TP1 in the lower right corner of the board Using the plastic tuning tool adjust inductor L8 for a maximum meter indication Connect the multimeter return lead to board ground to TP2 s rightmost pad left of the BNC jack Adjust inductor L9 for maximum meter indication Adjust the master volume slider Speaker icon for a DC voltage reading of 5 to 8 ...

Page 25: ...display Repeat this probing moving back upstream toward the receiver input through the signal path If there s a stage where the chain is broken and there s no longer any response chances are good that s where a problem is Transmitter troubleshooting general If an RF signal is getting to the transmitter final stage but there s no apparent output check the following measure DC continuity with an ohm...

Page 26: ...pattern and there s no information being sent If the signal is badly smeared by propagation conditions the phase information may be lost PSK31 is susceptible to polar auroral flutter DigiPan has an adjustable squelch threshold Click on the SET menu choice at the top of DigiPan and select Squelch Threshold check to ensure the threshold slider isn t set too high for the signal you ve selected and ad...