Small Wonder Labs PSK-20 Instructions Manual Download Page 19

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Small Wonder Labs



PSK-20 Transceiver Kit 03/09/10



2000

Group 8 Assembly:

Group 8 assembly installs the transmitter bandpass
filter and driver stages.

Note: U8 (MAR-3) is pre-installed on the board.

Install C32 (.01 uF disk cap).

Install C117 (.01 uF disk cap).

Install R47 (10

Ω

, brn,black,black). ).

Note:

there

silkscreened

reference

designator for this component.

Note its

placement carefully with respect to nearby
silkscreened component outlines before
installing and soldering.

Install R48 (220

Ω

, red,,red,brown).

Install C33 (470 pF monolithic cap, '471J').

Install C34 (100 pF monolithic cap, '101J').

Install C35 (4.7 pF disk cap).

Install C36 (100 pF monolithic cap, '101J').

Install C37 (470 pF monolithic cap, '471J').

Install L10 (1 uH SMT inductor, from the
'L10' envelope

Install L8 and L9 (remaining two Toko
tunable inductors, 'TKANS 9449'.

Install R49 (1K, brown/blk/red).

Note: there

is no silkscreened reference designator for
this component.

Note its placement carefully

with

respect

nearby

silkscreened

component outlines before installing and
soldering.

Install R50 (4.7K, yellow/violet/red).

Note:

there

silkscreened

reference

designator for this component.

Note its

placement carefully with respect to nearby
silkscreened component outlines before
installing and soldering.

Install R51 and R52 (10

Ω

, 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
silkscreen.

Install Q10 (2N2219, from antistatic bag).
Space this component 0.5 to 1mm above the
board surface to prevent shorts to the
transistor case. Observe the component's tab
orientation as shown on the silkscreen.

Install C38 (150 pF monolithic cap, '151J'.

Install R53 (51

Ω

, green/brn/black).

D10

TP1

C34

470

100

C36

C37

C119

4.7

D11

R52

R53

Q10

C32

.01

220

R48

L10

C38

150

C118

1N4001

R51

4.7K

R50

R49

470

1 uH

Summary of Contents for PSK-20

Page 1: ...s entitled First Things First and Building Instructions before you dive in These sections contain information which is key to your success with this kit TABLE OF CONTENTS First Things First 2 Materials 3 Parts List 4 Theory of Operation 6 Schematics 8 Pictorial Drawing 10 Building instructions general 11 Grouped assy Instr 12 Hooking Up 22 Alignment 23 Troubleshooting the PSK 20 25 Appendix 1 Freq...

Page 2: ...or color codes are given in the parts list Radio Shack s Color Code Guide 271 1210 or 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 20 board is doub...

Page 3: ...bly still be blocked with solder Use a dissecting needle or dental probe explorer apply heat to the probe 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 ...

Page 4: ...of 0 2 5 mm bend the wire leads gently to spread the spacing Avoid sharp bends right at the wire lead exit from the epoxy case this may cause component damage 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...

Page 5: ...etal 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 ohm Brn blk blk gold 4 R1 R39 R41 R53 51 ohm Green brwn...

Page 6: ... is fed with a 5 Mhz Local Oscillator LO signal and converts the incoming 14 Mhz received signal to the 9 00 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 two fold purpose it provides a stable load to the post amp and reduces filter passband ripple Y1 ...

Page 7: ...is 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 9MHz LO Colpitts oscillator Q7 and associated components The output of mixer U6 is a suppressed carrier double sideband signal After passing through the transmit...

Page 8: ... R49 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 150 150 330 330 220 uF 1 1 150 1 5 3 pl 1 51 10 1 10 4 7K 1K 100 470 1 5 uH 1 5 uH 470 100 4 7 4 20 22K 47K 47 2 pl 1K 3 3 uH 100 01 78L08 IN 5 07 01 1 uF 10K 2 2K 100 470 22K 220 10 uF C23 51 47 uF 2 3 1 1 0 XMTR AF...

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 22 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 9 00 MHz Y1 Y2 Y3 Y4 C9 C10 C11 C8 C12 22pF C7 C8 33 22 10 uH L5 R10 R9 R11 150 680 680 01 C6 R7 R8 C103 Q2 L4 10 uH 10 100 01 R4 V C102 01...

Page 10: ...47 uF R36 C23 10 uF R33 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 22 01 10K 01 C115 U7 01 22 33 C7 C8 R11 R10 R9 680 680 150 C114 C124 01 D9 D13 C1 22 D1 D4 L2 L1 4 7 uH 1 2 uH 220 uF C120 U9 Q3 C44 Y5 C48 Y6 5 0688 C112 01 10K R25 Q7 TP2 J4 L5 10 uH C3 C5 01 100 01 01 470 C101...

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: ... the two capacitor leads is Install diodes D16 and D17 1N4148s below J4 Match the installation polarity as shown on the silkscreen Install disk cap C110 01 uF 103 Install disk cap C124 01 uF Y10 is shown on the group 1 drawing for reference locating purposes and is not installed at this time Install an 8 pin IC socket at U5 Match the notch orientation as shown on the silkscreen Install resistor R2...

Page 13: ...4 Install R15 10K brown blk orange Install C16 and C108 01 uF disk caps Install C106 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 1...

Page 14: ...e 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 outward taking care not to bend the leads right at the capacitor body The wire leads may then be re bent a few mm away from the capacitor body to re form them at the correct parallel spacing Install transistor Q7 2N4401 from antist...

Page 15: ...scussion of the previous page for installation cautions Install C8 through C12 22 pF ceramic disk caps Install C7 33 pF ceramic disk cap Install four of the 9 MHz crystals at Y1 Y4 Install R10 150Ω brown green brown Install R9 and R11 680Ω blue gry brown Install C102 and C103 01 uF disk cap Install L4 10 uH RF choke brn black black Install R5 1K brn black red Install R6 470Ω yellow violet brown In...

Page 16: ...n polarities as shown on the silkscreen and on as shown on the figure on this page Install L1 4 7 uH RF choke yellow violet gold Install L2 1 2 uH RF choke brown red gold Install C1 22 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 ...

Page 17: ...nent outlines R40 and TEST are unused do not populate 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 ...

Page 18: ...4 C115 and C116 01 uF disk caps Install R43 1K brown blk red Install C30 and C31 01 uF disk caps 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 co...

Page 19: ...or for this component Note its placement carefully with respect to nearby silkscreened component outlines before installing and soldering Install R50 4 7K yellow violet red Note there is no silkscreened reference designator for this component Note its placement carefully with respect to nearby silkscreened component outlines before installing and soldering Install R51 and R52 10Ω brown blk black I...

Page 20: ...t L12 mounts at right angles to the two toroids already installed Remove the individual wires from the remaining length of wire bundle 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 threading operat...

Page 21: ...s into the corresponding holes in the board Do not solder yet Place the 1 4 6 3mm machine screw through the hole in the transistor tab and through the heatsink and printed circuit board Secure in 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 ...

Page 22: ...er 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 tailored to fit the enclosure side...

Page 23: ...K 20 s J3 connector with a 3 5mm 1 8 3 conductor cable Connect your computer speaker cable to the PSK 20 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 action may ...

Page 24: ...ning tool adjust inductor L8 for a maximum meter indication If the PA is getting hot due to prolonged key downs you may return to receive by clicking on SET and RX on the DigiPan menu bar 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...

Page 25: ...e 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 ohmmeter across R54 R56 to ground This reading should be appr...

Page 26: ...ion the properties dialog box has to be set to Adjust for Recording I ve clicked on a good signal but nothing s showing up There are several possible causes Make sure it s a PSK31 signal it should have the typical railroad tracks appearance on the display If it s just a pair of vertical lines it s an idling pattern and there s no information being sent If the signal is badly smeared by propagation...

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Small Wonder Labs PSK-20, Instructions Manual

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