Manual 80m version August 8. 2005
Contents
1. TX Output Filter C8 03 12 2002 SOLF DK1HE ge ndert 7 3 03 DL2FI Revision 03 August 2005 Revision 03 August 2005 7E 77 SOLF 12 2882 Section 6 TX Mixer up to the input of C88 10pF C101 ceramic trimmer 5mm 10 50pF C102 ceramic trimmer 5mm 10 50pF R25 330 R26 22 R27 18 R28 3 3 C52 47nF 53 2201 54 220pF COG C55 220pF COG 56 270pF COG C57 10pF 58 220pF C59 1500pF COG C64 47nF C65 47nF 1 116 toroid 50 2 red 3 AT 3 40 14 turns copper wire 0 3mm AARG Xo 1 2 are the coupling winding V US gt L7 toroid T50 2 red 7 FTN NS 44 turns copper wire 0 3mm 2 BEWARE 17 should be wound site to the rest of the coils because the location of the PCB holes is geometrically opposite Dr 2 RFC 47H SMCC IC6 NE612 SA612 T3 5250 7092 011 ZPD 5V6 Carefully check marking don t confuse with 1 4148 Q8 4 915 MHz Crystal HC18U Go to the test in appendix F 29 RX Preselector RI VER D K1 H E Monoband T RX 8V Abgl opt 4915KHz IF Filter 4120R 21 C2 C25 Eu zu AGC Peak Det SPARROW os 190 100 220p bie 6V 33u 20 En 56k R13 min 32 Ohms Earphones AA119 AGG C105 47n HI 22. T 8 TH I holes are plated through This means that you need rrr 4 not and indeed should not solder on the compo i 54 nent side of the board How to recognize a good and a bad soldering GOOD BAD Ideal the soldering point Too much solder 1S rounded and concave has been added Touch pc board and component at the same time with the soldering iron Within one two seconds add solder to see solder flow at soldering point Pull away solder and then pull away soldering iron Don t try to fill up the soldering points with solder Too much solder leads to trouble as it can bride pc board or components Press components as far into the board as possible This is not a question of good looks but an RF technical must Resistors should be flush with the pc board when not indicated that they should be mounted standing Capacitors have to be flush too In other words No components with long wires Please read the following before removing components from the pc board gt lt Noooo Sooner or later you have to remove components that have been soldered into wrong places or a parts has to be removed to locate mal functions Get a roll of solder wick Put the end of the solder wick on the soldering point to be removed and push the soldering iron to the wick After a few seconds you pull as the wick absorbs the solder Remove the wick verti cally never to the side Repeat thi
3. 3 7 1500 AGC Amp PF 20 100 _ 5 RX Mixer 4915KHz 22n C p LO 500mVss Bro 150 A 0 01u 0 047 5608 18k 8V Step 7 8V C37 Superheterodyne VF Ges AF Final Amp 2k2log V FS Meter Volume 6V BF244A 4 80 13 5V C91 od 50p ss EL 51 Output oh 10p WD J 820 i BF244A Ampl Dr 1 e D11 d 1 4 IC5 RX Input um m XTAL 11MHz LO 100mVss C52 L11 58 BF199 18k 50p 120 f 8 C61 22n C60 220p T R29 I Abgl C78 C79 C8 C8 0 2 560 560 560 560 70p 33p TX Output Filter 4 915Mhz ila Dr 3 TX Output adj cof c7 2k5 12 n TX Mixer Ampl 03 12 2002 SOLF DK1HE ge ndert 7 3 03 DL2FI Driver Revision 03 August 2005 30 03 August 2005 Revision 1869 71 09 TI ooo os s d 5 B AN DK THE y 12 2002 DL ORP AG Section 7 Exciter and amplifier up to and including TR1 C86 R29 2k2 Trimming value R30 33K R31 8 2 R32 150 R33 10 left out if too much output R34 10R C60 47nF C61 47nF C62 220pF C63 15 22pF if too little output C66 47nF C67 47nF 74 100nF 92 47uF careful about polarity 103 ceramic trimmer 5mm
4. Pack80 7 220pF NPO ceramic trimmer 50pF T50 2 red 15pF NPO ection 8 1uF 63V MKS2 5 100nF 1N4148 22nF 47R FT37 43 251969 FT50 43 HH H H mB B 0 mPB mp mp 41 Parts list Sparrow DDS VFO Parts list Sparrow Packing list Sparrow Peripheral Parts om L L L LII N no 1 0 1 uF CERAMIC MONO enclosure 1 Section 1 8 packs 1 22 uF 10VSUB MIN 4x7 mm Stereo connector 2 Peripheral parts incl PCB 1 Diode 1N4148 Micro switch 1 enclosure 1 LED red 2 1 mm power socket 1 drillig guide front back bottom 1 LED socket 2 1mm power jack 1 foile back front 1 3 3 V Voltage regulator Schalter 1 x ein 2 protectiv foil front back 1 100 R Fuse 1 25A 1 manual 1 10 k Fuse socket 1 DDS kit 1 220 R 100nF 2 1 2N7000 TO 92 MOSFET 1 Potentiometer 2k2log Volume 1 1 CLOCK 25 000 MHz CMOS stand off 8mm 4 1 CPU ATMEL 9052313 10 screw M3x7 8 1 shaft encoder screw M3x10 1 1 Crystal 4096 kHz nut M3 2 1 Transistor 2N3904 1kOhm 1 1 connector 7pol stand off 20mm 1 1 7fach Crimp connector screw M3x25 1 1 0 1 uF SMD 0805 front film 1 11 0 01 uF SMD 0805 back film 1 2 100 pF SMD 0805 protective film 2 2 22 pF SMD 0805 drilling guide bottom 1 1 220 pF SMD 0805 drilling guide front 1 3 33 pF SMD 0805 drilling guide back 1 1 100 uH SMD 1008 pc board 1 2 2 2 UH SMD 1008 knob 30mm 1 1 10 k SMD 0805 Knob 12mm 1 1 22 SMD 0805 cover for knob 1 1 270 RSMD 0805 rubber feet 3 1 3k9 SMD 0805 BN
5. Resistance test 3 Smoke Screen test Funktionstest The last section No more trimming only measurement Please keep in mind only to turn on the transmitter for a few seconds as long as the Sparrow not is fitted in the enclosure Hook up a dummy load to the antenna terminal If you have got one use a Watt meter Commercial Watt meters won t give better accuracy than some 10 15 of full range More precise is the measurement of RF voltage at the dummy load with an RF probe or a scope Don t forget to calculate the effective voltage from the p p value Naturally the best way to measure is with a calibrated Wattmeter for QRP e g the OHR WM2 Short the keying terminal shortly to measure the output If it is larger than 1 Watt adjust with P5 you won t need any more testing the Sparrow can be fitted in the enclosure and after that re trimmed 39 Appendix I Winding instructions for transformer TR1 The transformer TR 1 should be wound a double hole core pig nose core Put the core in front of you so that both channels run from left to right TR1 contains a primary of 5 turns and a second ary of turn Like in most other transformer diagrams you will find one end of a coil marked with a point This point ALWAYS designates the beginning of a turn also in simple coils Cut a 20 cm pies of 0 2 mm wire and put it through the core as shown in the picture One turn is complete when the wire passes through both holes
6. BFO VCA 8 A of Fe DDS VFO input AGC Peak Det 100n C2 D4 AA119 C24 li T 8V Version 80m 5 7k D11 8V R24 RX Input Band XTAL 11MHz 27 5V6 C64 C65 U key R25 T3 C69 L9 LO 100mVss C52 R36 4 220p R34 24 4 17 25 150 10R 108 TX Output adj 2k5 TX Mixer Ampl Driver 44 Ho 33nF 47uH 10 60 1 3 BS250 I C7 1 25 1969 C6 Te 1 IC 3 22N NN R35 2 4 D12 c67 1 Folie Dr 3 Dr 4 RH 12 n Hoon PA D13 DK1HE Monoband TRX SPARROW 56k 33H R13 min 32 Ohms 470R DS Earphones 119 NT k C28 0 01u 1 C33 AGC Amp at C31 1000 R11 ou Sa RIO R12 LE 22u 0 01u 0 047 A I m a OBZ AF Final Amp FS Meter Volume 6V BA479 L10 L11 112 e C79 C81 C82 2 4 AT Op 560p 560p 560p 560 470p 33p Tr 2 TX Output Filter 03 12 2002 SOLF DK1HE geandert 7 3 03 DL2FI Revision 03 August 2005 Revision 03 August 2005 DDS 2 485 2 585 MHz Q6 11 000 MHz 4 08 4 915 MHz LO Frequenz IC6 8 415 8 515 MHz 3 5 3 6 MHz Ius 3 5 3 6 MHz ZF Q1 Q4 4 915 MHz gt lt gt lt 2 BFO Q5 4 914 MHz 45
7. Each and every one of us should put the wire the way he wants 2 But this forces a winding direction to have the proper geometry of the toroid If you put in the wire from the back forward you must continue winding clockwise for having the right geometry for the Sparrow If you put in the wire from the front backward you have to wind anti clockwise This is only so for the Sparrow Other developers have other preferences Wayne the constructor of K2 wind opposite to DK1HE When you know the background a simple test winding will soon show how the constructor planned it Put 23 turns on the toroid well distributed on the ring If you count the 7 2 1 turns on the INSIDE of the toroid you can t be wrong The inductor in the picture e g has 8 turns Well distributed means that the wished number of turns fills about 270 degrees of the ring That is about the you wind you won t need to pull the turns apart later on even though it to some degree is possible turns shouldn t cross but should be in one layer Take care on each turn that it is pulled tight With powder cores this is no problem maximum for toroids If you are careful about this when as the edges are smooth But with ferrites this can pose a problem as the edges are somewhat rough Cut off the rest of the wire but not too close and solder the ends Whats best That s for debate The lacquer on the wire
8. K 10 D 0 5pF 20 1pF if gt dann 41 S 20 50 G 2pF if gt 10pF dann 2 Y 0 100 1 5pF 2 20 80 Some of these are so uncommon that I havent seen them 5 is really the most common This marking is mainly used for discoid capacitors Film capacitors usually use the p Farad as base 0 22uF 200nF 0 033pF 33nF 0 0015 1 5 nF Ceramic capacitors usually have an additional color coding representing the temperature coefficient To us the most important are the ones with a black yellow or violet stripe Black means NPO yellow means NP220 and violet means NP750 A lot of others exists but are uncommon It is very important to choose the right capacitor for the job The material of which the capacitor is made makes a large difference The reason is mainly the different Qs of materials Ceramic capacitors mainly have a high 0 They are preferred 1 RF circuits e g as parallel capacitor in resonant circuits Ceramic capacitors mainly come as disks or small squares Multilayer capacitors come as NPO types even those with a high Q Their 88 fordel for us kits builders is that they are lacquered and thus the print on them not so easy to damage as it is in ceramic capacitors Multilayer capacitors are mainly cushion shaped desvaerre it isn t possible to distinguish them from simple X7R or ZU5 capacitors just by looking X7R and ZU5 are materials of lesser Q They are
9. L11 C76 C8 0 2 560p 560 560 560 70p 5 33p TX Output Filter C8 03 12 2002 SOLF DK1HE geandert 7 3 03 DL2FI Revision 03 August 2005 26 Revision 03 August 2005 es 5 e SPARROW SOLF 12 2082 1 DL ORP AG Section 5 RX input including Lowpass Filter LPF R1 470R R36 1K R2 1k R40 Trimming value optional Please be careful with the orientation of the IC Pin 1 is in the notch end of the IC IC1 612 5 612 The following diodes must be identified under magnifying glass as they look very much the same On the glass casing you will find small but legi ble print D1 PIN Diode BA479 D2 ZPD 4V7 013 PIN Diode BA479 014 PIN Diode BA479 optionals Then follows the capacitors C1 22nF C2 230pF 1500pF COG 4 22nF 5 5 6pF C6 5 6pF C7 220pF 22nF C9 330pF COG RM5 C10 220pF COG RM5 C70 22nF C76 120pF C77 not installed C78 560pF COG C79 560pF COG C81 560pF COG C83 33pF COG 75 film trimmer black C80 560pF COG C82 470pF COG C104 22nF optional L L LLLI L L L L L LI LLL LLLI LLLI LIII C97 ceramic trimmer 5mm 10 50pF C99 ceramic trimmer 5mm 10 50pF C100 ceramic trimmer 5mm 10 50pF ma m eI 1 L1toroid 150 2 red 44 turns 0 3mm copper wire L2 toroid 15
10. from high RF voltages The preselector consists of two capacitatively coupled parallel resonant circuits with a high 0 This gives a good selectivity and increases the intermodulation characteristics D1 works as an attenuator during transmission and reduces the transmitter signal to prohibit too high AGC voltages to allow listening in the keying pauses QSK In reception D1 will be blocked by the voltage of the zener teen rte Eee erable ae c diode D2 and thus increase in impedance The signal can be further redu ced the optional diode 014 To inhibit further intermodulation effect due to non linear diode characteristics PIN diodes are used for D1 D13 and D14 as they work as controllable linear resistors The filtered reciever signal is inductively and symmetrically coupled to the reception mixer IC1 via L2 Below you will find a simulation of the entire 40 meter input circuit done with RFSIM99 The software is Freeware so you are free to play with the components Sha LH peiie P L IC1 amplifies the received signal after mixing with the local oscillator and ENTM 4 Revision 03 August 2005 LO e O N 5 5 lt Revision The following capacitatively coupled band pass filter based on L6 L7 strips the unwanted mixer products 58 59 transforms the high output impedan of the filter to the input impedance of the amplifier 14 P5 regulates the emitter curre
11. in the 50MHz band 3 On the circuit outputs the 4915 kHz IF The DDS VFO gives a 2485 to 2585 kHkHz signal stable as a crystal Transmitter oscillator This is buffered in T2 and input to the Gilbert cell mixer IC4 where it is mixed with an internal band set crystal oscillator 11 000 MHz mixes the local oscillator signal with a 4915 kHz carrier 4915 kHz signal based on Q6 On the output of the mixer a loosely coupled highly signal is produced by the internal oscillator of IC6 in conjunction with Q8 selective parallel resonant circuit with L5 will clean up the LO frequency C38 C39 gives a low loss coupling to the gate coupled amplifier T1 The output circuit around L4 further increases the spectral purity of the amplified signal The local oscillator signal is sent by C9 the divider C35 C36 to the transmitter and reciever mixers respectively The optional JFET buffer 8 15 for low 1055 coupling of an external frequency display Receiver Attention the pictures show 40m as an representative example f The antenna signal goes from the transmitter output filter through the series resonant circuit C75 L9 to the RX preselector As the PA transistor T7 is blocked during reception class C operation Tr2 is only active with its relatively high inductive reactance and will only load the antenna signal very little 013 with be conducting during transmission and will thus a protect the receiver
12. integrated electronic keyer for speeds between 10 WPM 50 cpm and 40 WPM 200 cpm HAND key If the DIT contact is closed during power on the internal keyer electronic is switched off and the DIT contact can be used for a pump key or an external keyer Changing the keying speed The keying speed is changed by pushing the Rate switch and the paddles The Rate switch has a 0 5 s delay before changing the rate If a paddle is activated within this period it will change the keying rate The VFO stays in this mode till the Rate switch is released The dot paddle raises the speed the dash paddle lowers it 19 While changing keyer speed the transmitter keying is disabled and the side 22 uF 10VSUB MINATURE 4x7 mm tone oscillator will sound an A to give the user a feel for the actual keying Diode 1N4148 rate Holding down the paddle will repeat the change till the upper or lower LED red limit is reached This rate change is in steps of 2 WPM 10 cpm 3 3 V Voltage regulator 100 5 1 4W Memo 10 k 5 1 4W CARBON FIL There is one memory position 220 5 1 4W One long push gt 1 s stores the present frequency in memory The RIT LED 2 7000 0 92 MOSFET blinks twice to confirm if the RIT is off CLOCK 25 000 MHz CMOS 1 2 SIZE DIP A short push switches between present frequency and stored frequency The CPU ATMEL A90S2313 PC10 programmed yellow LED blinks once when the frequency changes It starts 030 inthe DDS ANALOG DEVICE
13. power D10 1N5402 The two pole connectors have a security nose Please note the correct position on mounting to avoid problems later on The side with the nose is marked in the placement diagram 2 pole 12V connector 2 pole Key connector Bridge as marked on placement diagram and place 2k2 resistor on bottom side of pc board Se Kathode When all components mounted please through check of appendix 9 10 DK1HE Monoband TRX SPARROW 6V min 32 Ohms D5 Earphones C105 47n 1N4004 C28 0 01p AGC Amp 9 4 7 R4 ul 10R 4u 2k2log Volume Step 2 80m 2k2 R24 27k C69 33nF 03 12 2002 SOLF DK1HE geandert 7 3 03 DL2FI Revision 03 August 2005 a 4 E 5 78 60 FEM amp eee 5 a 5 E a 9 T 4 e N 4 om 29 29 A 5884 sos L8 os SOLF 2 2087 6 24 72 177 DL OFP R6 Section 2 AF output stage AF preamplifier stage Please begin with the resistors once more R10 and R12 should be mounted standing up To do that one lead must be bent back along the resistor body In the placement
14. the 40 meter Sparrow we use several types of toroids In the low pass filter 137 6 yellow in the band pass filters and resonant circuits 37 2 red except where we use the somewhat larger 50 2 The is wound on 37 43 and the output transformer TR2 also on the larger powder core toroid 150 2 Initially you can take note that powder core toroids are used for narrow band applications and the ferrites for wide band applications On the CD you will find the Mini RK program by Wilfried DL5SWB With this small helpful program it is piece of cake to calculate the proper number of turns for a given inductance or the inductance if you know the number of turns Winding toroids gives many kit builders fears This is unfair according to me If you meet with no prejudice and remembers the basic rules nothing can go wrong Important a wire put through the toroid means a turn For training you should wind a toroid we ll take L4 as is is an inductor we need in section 4 Cut about 25 cm of the 0 3 mm copper wire take the toroid and put in one end of the wire Now one turn is done but STOP Look at your work and think about how you put the wire through the ring gt There are two possibilities You can put in the wiere from behind forwardly as girls used to sew from the front backward For the RF is equal but for the mounting it is not as the holes in the pc board are made for a specific lt direction
15. turns are wound in the Same direction as the primary The drawing makes this clear BEWARE the number of turns in the drawing does NOT correspond to the actual numbers 3 4 15 the primary 1 2 is the secon dary 3 oe B1 oA 1 4 612 5 612 T1 BF244A T2 BF199 T8 BF244A Q6 11 0MHz 32pF HC18U 2 L5 Toroid 137 2 red 25 8 0 3mm copper wire mA C47 left out C48 left out C49 left out C40 left out 51 left out If a counter is to be connected you can use the soldering connection at point Counter on the PCB Finish this section by doing the tests of appendix D 25 RX Preselector RT K1 E Monoban d T RX C1 Abgl opt 4915KHz IF Filter BA479 u E AGC Peak Det SPARROW 100 100 11 Q1 02 03 Q4 qug H n 0HIE Rma E 6V 33 56k 998 D3 R13 min 32 Ohms C12 C14 220 230 220 ax HI C94 C1 C18 150p C20 Op 33p RX Mixer 4915KHz LO 500mVss Bro L 90p H AGC AA119 205 DS Earphones C105 47n mo AGC Amp ay C31 I R11 AF Final Amp 2k2log Volume 22n 8V C37 FS Meter 6V BF244A Counter C91 ab C90 N Output 10 10 1 wi uo 1k 100K BF244A 30p 2k2 150g C39 R24 Band XTAL 11MHz 27 1 4 1 5 13 U key
16. 0 2 red 41 3 turns 0 3mm copper wire BEWARE 3 4 secondary G 11413 toroid T50 2 red 29 8 turns 0 3mm ean 2 copper wire BEWARE 3 4 secondary L 4 L9RFC 47 uH SMCC 110 toroid T37 2 yellow 22 turns 0 5mm copper wire L11 toroid T37 2 yellow 24 turns 0 5mm copper wire 112 toroid T37 2 yellow 22 turns 0 5mm copper wire When you have mounted all components go to the test in appendix E 27 R1 R40 RX Preselector C1 Abgl opt 4915KHz IF Filter c1 Q1 Q2 Q3 HI C94 C1 C18 150p RX Mixer 4915KHz LO 500mVss BFO 150p 8V C37 6V BF244A C91 C90 ES Output oh 10p uo 820p cu 244 U key D11 T 5V6 R25 C64 NER LO 100mVss C52 330R 5p6 47n R27 58 18k gt I I 50p 1120p C53 co N 5 E 24 4 915Mhz 28 IF Amp Dem BFO VCA iL 27 4120R JH BA479 C21 C2 li C25 1 230 za E C20 Op 33p Q H 22n DK1HE Monoband TRX SPARROW 8V AGC Peak Det C2 04 a 6V NEN 33u 56k min 32 Ohms 470R D5 AGC AA119 Earphones 105 47 92800 AGC Amp IC3 8c E R11 Rid p42 2k2log Volume AF Final Amp FS Meter Step 6 RX Input L11 C8
17. 10 50pF T4 BF199 4 9 15 BF199 Ferrit bead on collector 27 bead Diagram of BF199 note that it is not the standard TO 92 EBC configuration 1 Collector 2 Emitter 3 Base Ferrite bead placed over collec tor of 15 The driver 2 2219 is in a 1039 metal casing BEWARE the casing is connec ted to the collector and is on positive potential Here it is easy to short out while measuring View of the bottom L8 toroid 150 2 red 41 20 turns 0 3mm copper wire reduce secondary windings if too much output Dr 3 47uH SMCC Tr 1 Two hole core primary 5 turns 0 2 mm copper wire secondary 1turn 0 5mm copper wire A thorough description of how to wind TR1 is found in appendix I P5 trimmer potentiometer 10k PT6LV Go to test in appendix G 31 R40 RX Preselector C1 Abgl opt 4915KHz IF Filter BA479 8V 6V BF244A IF Amp Dem BFO mer We DK1HE Monoband TRX SPARROW 8V AGC Peak Det TiO0uF 100n 100n 11 Q 45 Hill HIE a 3 16V 33u D3 14 2502 ES zanl 1 15 1 56k 9 min 32 Ohms LI Earphones ic dio C105 47 n 2 T C94 ei BE A244 TCA440 D C20 25 Q RX Mixer 4915 2 CV gen ou LO 500mVss BFO 123 R10 2k2log Volume AF Final Amp FS Meter 8V St
18. 6k D3 R13 min 32 Ohms 4708 05 AGO Earphones C105 47n mo C31 I R11 1 AF Final Amp 2k2log Volume 8V 2k2 R24 27 RX Input C69 33nF 03 12 2002 SOLF DK1HE geandert 7 3 03 DL2FI Revision 03 August 2005 4 2002 Section 4 VFO Mixer C50 C44 C41 C39 C36 C37 C91 98 Lo L L Revision 03 August 2005 R19 47K R16 2k2 Dr 1 left out R37 100K 100pF C45 10nF 271 120pF 820pF COG 150pF 22nF 10nF eee 0 111 20 n 17 w 811 nun Ts a vy 0000 ei ps 3 R18 R17 R15 R38 C89 C46 C42 C43 C38 35 90 96 ceramic trimmer 10 50pF DR1 left out C40 left out nd counter read out 820pF NPO 10pF _SPARROW ceramic trimmer 10 50pF L 4 15 a simple one layered coil with 0 3mm copper wire When winding it care must be taken that the wire ends are where they should be to fit the holes in the pc board The right winding direction is important If the wire is put in from the back forward the winding should be clockwise L4 Toroid 137 2 red 24 turns 0 3mm copper wire 5 becoms a secondary As seen in the diagram this should be symmetrical ly wound on the primary It is important that the
19. C connector 1 1 470 RSMD 0805 pc board 1 2 68 R SMD 0805 copper wireo 3mm brass colour 4m 2 213904 507 23 SMD copper wire 0 3mm red 2 1 DDS AD9835 BRS copper wire 0 5mm 2 1 4 7pFSMD 0805 extern copper wire 0 2mm 1 pc board DDS Revision 03 August 2005 03 August 2005 ision Rev 194128 220 iH IM 4 AN 2N3304 Od Spannungsregl er 3 ay T Extern 470p nach 10k Pint 20 LELET 44 6 4 q 144 21 2 ERLUDEH A 3 ENCODER B a SIDE SELECT a 2 2 E Ps 5 ia Se ee 1 BITS 0 eer 12 12 T 2 23 022 F lan 3 d H irs L AYL D 67 1 OLD ove COMP T c1 Cz LF CH oon 1686 Orehencoder cz 1 2Hx5404 SNE E Draufxzicht CLOCK AMNH Appendix H Schematic DDS VFO 43 R1 R40 RX Preselector C1 Abgl opt 4915KHz IF Filter 22n D BA479 ___ 100uF 100n R6 C11 03 04 cis Itti IL 3 EEA a i C94 BE c9 C20 330 Q5 x 1 22n 6V RX Mixer 4915 2 LO 500mVss Bro 159 12 6V BF244A pun au oh IF Amp Dem
20. C93 100nF 104 Revision Now come the electrolytic capacitors Please note the polarity On the body of the capacitor you ll find a minus marking and you ll find that the long lead is the positive pole C85 1 radial C87 47yF radial The last capacitor is 0 22uF MKS Foil capacitor This type is used when a high Q is needed especially at AF MKS capacitors should never be exchanged with X7R capacitors of the same value C69 0 033 uF MKS Foil Cap 5mm C86 1pF radial Many small signal transistors and voltage regulators are made 9 in TO 92 cases The component placement drawings show all fi components basically from above When mounting please note the direction of the rounded part of the casing iif Please do not mix up the two voltage controllers which are both in 1092 the 8 V regulator is marked 108 and the 6 V regulator marked LO6 Voltage regulators like these look simple but are quite complex inside They contain several dozen compon ents and delivers a constant output voltage as long as the input voltage is at least 1 V over the output voltage 108 78106 9 78108 fee am 1 p The diodes have a ring around their body to mark the cathode For diodes in plastic casing this is easy to see but on diodes with glass casing it can be quite difficult In this section you ll use one large 1N5402 in plastic as a protection against wrong connection of
21. CO N ES S S E LLL P Lu OO O O LO XO AO WO O WO HO O N OF Ul UO e Section 6 TX Mixer up to the input of T4 Section 7 Exciter and amplifier up to and including TR1 C86 Section 8 PA Wiring diagramm Sparrow Fitting in the enclosure Appendix A Test for section 1 Appendix B Test of section 2 Appendix C Test of section 3 Appendix D Test section 4 Appendix E Test section 5 Appendix F Test section 6 Appendix G Test section 7 Appendix H Test section 8 Appendix I Winding instructions for transformer TR1 Packing list Sparrow Parts list Sparrow DDS VFO Parts list Sparrow Packing list Sparrow Appendix H Schematic DDS VFO Schematic Sparrow Block Diagramm Revision 03 August 2005 LO e st 20 35 lt e Monoband QRP CW Transceiver SPARROW tentative english translation by Peter Raabye OZ5DW 18 04 03 Not verbatim readability was a priority By Peter Solf DK1HE Project coordination and editing Peter Zenker 0211 With support from J rgen DL1JGS Prototypes manual and Wolf DL2WRJ Programming of the DDS VFO Preface Even in times of modern all band technology there is a continuing interest in monoband QRP CW transcievers Most are presented as easily and quickly built kits and are thus well suited for both newcomers and oldtimers The experience of trouble free QSOs with a home built simple transciever won t compare t
22. DA7050 ection 3 1 tantalum 10uF tantalum 100uF 16V rad 100nF 120R 150pF NPO 18k 1k5 PA pP n H P e Ul PP HPP H HP pP P HP HP Pn WNP PPP n HB H HB DB H HP HB HB H Ui P PWM UT PO P no PY 220pF NPO 220R 22nF 27R 2k2 2 pole connector 33p as C17 see text 33uF 16V rad 470R 56k A244 440 AA143 trimmer 7mm black IC Sockel 16 pole flat Pack 80 3 Crystal 4915MHz matched ection 4 100K 100pF 10nF 10pF 1K 2 2K 22nF 47K 47nF BF199 BF244A NE612 SA612 Pack 80 4 820pF NPO 150pF NPO 120pF NPO 47 pF NPO ceramic trimmer 50pF 11MHz Crystal T37 2 red Section 5 1k 22nF optional 470R NE612 SA612 PIN Diode BA479 ZPD 4V7 150 2 rot Pack80 5 220pF NPO 1500pF NPO 5 6 pF NPO 470pF NPO 33pF NPO 560pF NPO foil trimmer black ceramic trimmer 50pF T50 2 red SMCC ection 6 18K 220pF COG 22K 22nF 3 3K 330R 47nF BS250 T092 RFC 47uH SMCC NE612 SA612 ZPD 5V6 Pack80 6 200pF NPO 10pF NPO 220pF NPO 1500pF NPO ceramic trimmer 50pF Crystal 4915MHz LA LS Q LES LS LES LS gt 1 P DMP UO Uu 2 T50 2 red Section 7 1 100nF 2 10R 1 150R 1 2N2219A 1 33k 1 47uF 1 SMCC 4 47nF 1 820R 1 8k2 2 BF199 1 two hole ferrite small 1 Ferrite bead 1 potentiometer 10k PT6LV 1 Unterlegscheibe f r Transistor
23. F from PIN 1of the processor to ground and 10 kOhm from PIN 1 to PIN 20 4 7 as shown in the Photo R6 68R C15 33p 22k CM L3 100 C21 M R9 68R 81 RF out Es E C16 1 nF 21 Bestuckung Mini DDS VFO nach KD1JV Oberseite Version Spatz Mods DL2F1 DL6DSA T Di entfallen bei Spatz oT TC JI EIEcS061V 2 9 Side J J2 2 Dot Band 3 Ae 1 42 1 Dash Band 2 3 3 V Regulator U1 Pin layout 22 26 02 2002 F r Spatz LED RIT nicht best cken Statt dessen 2 Drahtchen von Anschluis RIT LED zur Frontplatten LED f r RIT Anzeige 25 MHz Oscillator IC Socket R2 10k Q3 2N7000 Q1 2N3904 R12 100R D7 1N4148 X1 Crystal 4 096 MHz U1 3 3 V Voltage regulator take care on moun ing oblique 19 22uF R10 220R C20 100nF R1 220R connection wire for RIT LED connection wire for Rate switch a FA m3 emo en D L L L L LLL LLLI LIILI LIII LJ The DDS VFO should be mounted with the 20 mm stand offs and the long M3 screws to the lower right positi on TEST To test the VFO roughly the connector at J1 has to be connected Look at the wiring diagram to connect the shaft encoder correctly If you connect a piece of wire about 10 cm to the point marked RF on the bottom s
24. Resistance test 3 Smoke Screen test Functional test Hook up the VFO and short the KEY terminals Set trimmer C101 and C102 in center position At MP8 you should be able to measure a 3 5 MHz signal which stems from mixing the local oscillator with the 4 512 MHz crystal Now connect MP8 to a receiver just as when tuning the receiver part of Sparrow This time the external reciever must be tuned to 3 560 MHz Tune both C101 and C102 to maximum signal If you work with an RF probe or an oscilloscope you will also tune to a maximum signal If a trimmer is at its maximum you will need to remove the corresponding coil and rewind it with one more turn If any trimmer is at a minimum you will have to remove one turn The drawing left shows the minimum position of a trim mer Appendix G Test section 7 1 Visual inspecton 2 Resistance test 3 Smoke Screen test Funktionstest The test point is directly the casing of transistor T6 To terminate Trafo 1 properly put a 25 ohm resistor from TR1 PIN 3 to ground Measure the RF signal with the RF probe the scope or the external receiver and trim the Revision 03 August 2005 Revision 03 August 2005 ceramic trimmer C103 to maximum signal With the potentiometer P5 TX Output Adj you can set the amplification of this stage When the trimmer is at maximum or minimum you will have to change the coil as previously described Appendix H Test section 8 1 Visual inspecton 2
25. Revision 03 August 2005 DL QRP AG project Amateur Radio LE AE SP RA i e PE i tE Ea 1 Sparrow Monoband CW Superhet Transceiver 80m Version QRPproject Motzener Stra e 36 38 12277 Berlin http www QRPproject de Telefon 49 30 85 96 13 23 e mail support QRPproject de Manual by Fiservice Peter Zenker DL2FI email info 2qrpidee de Index Monoband QRP CW Transceiver SPARROW Preface Technical data Description of individual stages Local oscillator Receiver Transmitter Transmitter keying and RIT Voltage controller The first steps What you need to know Soldering Soldering iron Before removing components from the pc board If you don t know what to do Section 1 Voltage regulation keying section Section 2 AF output stage AF preamplifier stage Section 3 IF amplifier Small toroid and component school Toroid inductors The formula for powder cores looks like this Capacitors The DDS VFO for the Sparrow Functions of the DDS VFO Tuning Showing the band edges RIT R eceiver I ncremental Tuning XIT X mitter I ncremental Tuning CW keyer Changing the keying speed Memo AFA Parts list for the Sparrow DDS VFO Section 4 VFO Mixer and counter read out Section 5 RX input including Lowpass Filter LPF 2 DOH U1 KR WW UO UO
26. S AD9835BRS 40 meter version When no memory frequency is stored the VFO will go to Shaft encoder 7 030 MHz in stead Crystal 4096 kHz Transistor 2N3904 AFA PC Board A udio F requency A nnounciation A longer push on the tuning knop reads the frequency out in morse via the side tone The values for 100kHz 10kHz and 1kHz are read out the accuracy is abt 1kHz In RIT and XIT mode the AFA gives out the difference between TX and RX frequency with a higher resolution Parts list for the Sparrow DDS VFO 0 1uF SMD 0805 2 0 01 uF SMD 0805 11 100 pF SMD 0805 2 22 pF SMD 0805 2 220 pF SMD 0805 1 33 pF SMD 0805 3 100 uH SMD 1008 1 2 2uH SMD 1008 2 10 k SMD 0805 1 22 k SMD 0805 1 270 R SMD 0805 1 3k9 SMD 0805 1 470 RSMD 0805 1 68 R SMD 0805 2 2 3904 50 23 SMD 1 0 1uF CERAMIC MONO 1 20 PPP PP PPP Revision 03 August 2005 Revision 03 August 2005 AD9835 C2 100nF R4 2708 C4 100p C3 10nF T C7 33pF L1 2 2uF R3 3 9k C5 220pF C9 10nF C1 100nF 1112 2 2uF C8 33p C6 100p 9 10 10nF C13 10nF ni CAS R5 10k 02 2N3904 1 33p C WN 45 470R R6 68R 22011 1 C15 33pF R7 22k 3k9 C14 10n 13 100uF C21 10nF R9 68R C5 220p 16 10nF C23 10nF 10n C9 C22 10nF C17 10nF 11 C18 10nF P BEWARE modification 470p
27. Screen test Functional test Section 5 completes the receiver When all is well you can start hearing signals with the Sparrow Once again hook up the head phones the volume potentiometer the field strength meter or the short and the VFO Use to short pieces of wire to connect the antenna connector to the two points marked ANT on the pc board Also hook up a signal generator or a low power transmitter connec ted to a dummy load QRPProject sells a cheap signal generator useful for this project You could also use an antenna out of sheer need The Sparrow is very sensitive and strong signals could be heard even with a detuned receiver front end Set C75 C97 C99 and C100 to their center positions Dial the signal generator or transmitter a little to and fro till you hear it in the head phones If you work on an antenna turn the VFO dial to any audible signal When you hear a signal tune C75 C97 C99 and C100 to their a signal maximum If a trimmer is at its maximum you will need to remove the corresponding coil and rewind it with one more turn If any trimmer is at a minimum you will have to remove one turn The resonant circuit C97 L3 shows no real maximum and is very uncritical as it is mainly there for the transformation The drawing below shows the MINIMUM setting The Sparrow reciever is now fully functional and we will continue by building the transmitter Appendix F 38 Test section 6 1 Visual inspecton 2
28. The color code chart next page shows how to read the four color bands on 5 resistors 1 resistors are similar except that they use five bands three significant digits multiplier and tolerance For example a 1 500 ohm 1 5 k 5 resistor has color bands BROWN GREEN and RED A 1 5 k 1 resi stor has color bands BROWN GREEN BLACK BROWN The multiplier value is 1 rather than 2 in the 1 case because of the third significant digit Because 1 resistors have color bands that are sometimes hard to distin guish clearly you should always check their resistance using an ohmmeter The markings RF chokes reflect their value in microhenries Like 5 resistors chokes use two significant digits and a multiplier Example an RF choke with color bands RED VIOLET BLACK would have a value of 27 uH Soldering Hopefully this is not your first encounter with a soldering iron If it is or this is your first semiconductor project read the following tips Soldering iron Use a 50 to 80 W soldering iron if possible A 0 8 mm pencil tip is ideal Keep the tip clean Use a moist sponge or a moist cotton cloth to clean the tip regularly during work On ground areas you might need a larger soldering iron tip vom 0 Only heat the soldering point enough for a good connection A small vise for holding the pc board is oh 4 1 a great help 2 Jir printed circuit board is double sided and all
29. We will when working with our pocket calculator assume that the capacitors are in the center position On the CD you will find an Excel spreadsheet which also calcula tes on start and end values For calculation of the inductance we first need the total capacity of the circuit We begin by the capacitor coupling C1 and C2 are in parallel so capacities add up 1 2 1 C2 C1 2 and C3 are in series For series coupled capacitors the formula tells 1 1 1 M C ges 1 2 C3 We solve further by multiplying on both sides with C3 C3 C3 1 C ges C1 C2 Then multiply by C1 C2 C3 x C1 C2 0034 01402 Cges And the multiplication with Cges C3x C1 C2 Cges x C3 T C2 C1 Then only the division by C2 C1 is left and Cges is C3 x C1 C2 ges 2401 Revision 03 August 2005 When the total capacity 1 known we use Thomsons formula to find the necessary inductance for the given frequency LImstellen der homsonschen schwingungsfon 1 2 IH m C 1 Muthiolikation mit Wurzel L C 1 x Vic gt 2 Division durch f Lc 1 Co C T a Quadneren 1 2 o 4 f 4 Division durch C L fe 3948 2005 2 As shown we now only need the wished frequency and the freshly calcula 3 ted value for total capacity to calculate the inductance for resonance The values for L f and are in Henry Hz and Far
30. Wind two turns Through the upper hole to the right leave about 2 cm hanging out of the hole Go back through the lower hole to finish the first turn Then go on through the upper hole again back through the lower to finish turn number 5 Wdg two Don t pull the wire to hard over Wa the edges the lacquer is easily scratched Continue with turn three four and five and the primary is finished You still miss the secondary As the in put of the PA transis tor 15 low imped 5 Wig 02mm 1 Wdg 0 5mm 40 ance we will transform downwards the secondary will only con sist of one turn of 0 5 mm copper wire To make the fitting easier our designer has put so that the secondary terminals are op posite to the primary Take a 6 7 cm piece of 0 5 mm wire push it gently from right to left through the upper hole and back towards the right through the lower hole The secondary 15 finished The transformer can be fitted The secondary comes as 4 3 the pri 5 mary as 2 1 L r 1 C67 Js H Revision 03 August 2005 Revision 03 August 2005 Packing list Sparrow 40 Section 1 0 033uF film 5mm 1uF radial 100nF 104 12V connector 1N5402 1N5822 27k 2 pole connector 47uF radial 78L06 78L08 2k2 ection 2 0 01uF film RM5 0 047uF film RM5 0 22uF film RM5 10uF rad 100 rad 100n 10R 18k 1N4004 or equal 22k 2 pole connector KH 3 pole connector 47uF rad 560R T
31. ack toroid BEWARE DR4 should be wound counterclockwise to fit the holes and then CLOCKWISE 4 times through the ring The power transistor 2501969 15 more than enough for the Sparrow 9 which makes it close to indestructible in this setup Here you will also have t to take care in measurements as the collector is connected to the casing S Because of this it has to be mounted on an isolator It is mounted on the pc board so that it is flush with the back edge The back wall of the enclo sure will work as a heat sink Between the transistor and the enclosure a grey silicone washer will fit over the screw Now test according to appendix H 33 34 2 1mm Hahi Ehen all Mk 1 1 13 010 FIT Kura ier Spat Mainboard a Fi 171 a f r Cairne SPRRI Revision 03 August 2005 Revision 03 August 2005 Fitting in the enclosure In the kit you will find a printed fil for the front and back and also a cover ing film for the front and back to avoid pull out and the drilling guides Begin with the four holes for the pc board The pc board should touche the back wall of the enclosure to make it possible to fix the PA transistor screw e ai ETT Beran to the enclosure Allways put a piece of wood unde
32. ad that is quite unhandy 5 If f is in MHz and C in pF we can directly calculate the size of the induc 5 tance in Henry e Now we only have the calculation of turns for the toroid left The formula for powder cores looks like this Lin WH 100 A entsprechend des verwendeten Kems i rr3 2 A 40 uH pra 100 L 37 8 A 30 uH pro 100 Wag On the CD you ll find the small programm Mini RK with which such calcula tions can be done directly Capacitors The years have brought several different standards for marking of capaci tors This is the cause of much confusion but I will try to shed a little light on it One method much used for industrial and multilayer types the small cus hion shaped mainly brown or blue capacitors gives the value and the power of ten of the value based on 1 pF The code consist of 3 digits where the last digit represents the number of zeros 100 10 and 0 zeros 10pF 101 10 and 1 zero 10 OpF 102 10 2 zeros 10 OOpF 1nF 103 10 and 3 zeros 10 000 10nF 104 10 and 4 zeros 10 0000pF 100nF Another standard uses the decimal name of the power of ten as decimal point 1 5 1 5 pF 2n2 2 2 nF Often a J is used in stead of the p for picofarad The J marks a capacitor with 5 tolerance 100J represents 100pF 5 and 1504 represents 150pF 5 17 The list of signs for tolerance are B 0 1pF J 5 0 25pF
33. al a small distance off the board A good trick is 14 to put a cut resistor lead between the crystal and board as a spacer when soldering in the crystal Remember to remove the resistor lead when done soldering 01 02 Q3 04 1105 Over and to the right of 01 and below 04 you ll find two holes in the board In these holes you should solder in 2 cut resistor leads or other wire bits and bend them at a right angle at about half height of the crystals Again at half height of the crystals the wires are soldered to all 4 crystals Solder briefly a hot soldering iron shortens the soldering time The crystals could be damaged if they are cooked for too long solder crystal cases to ground C21 100uF 16V rad Then mount the connector for the field strength meter 2 pole field strength meter connector IC2 Put A244 or TCA440 in the socket Mind PIN 1 Go to section test in appendix C of this manual When the test is OK we will at first look at toroids and then build the DDS VFO as both are needen for section 4 Revision 03 August 2005 Small toroid and component school Toroid inductors In the next section we ll need to use som toroid inductors We use high quality AMIDON toroids like our american friends In the general appendix of the manual you ll find the FAQ of the DL QRP AG with some general information on toroids If you are unfamiliar with toroids that is a good place to start In
34. and home 227 developed several excellent pieces of gear adding to the international succes of home brewing Since january 2002 I have spent a lot of time as chairman of the DARC Berlin Chapter as I feel a lot better doing things than just complaining The international QRP movement has taking me on as their first german member of their Hall of Fame I wish you good luck in building the Sparrow and 73 de Peter DL2FI 8V 2 2 R24 27 C69 33nF DK1HE Monoband TRX SPARROW 03 12 2002 SOLF DK1HE geandert 7 3 03 DL2FI Revision 03 August 2005 5 i 8 pui A 4 E a 2 E 7 a a TE ee eter egens P 4 CE Er m 9 4 a 2 29 DKHE SPARRUW uw UL ORP AG Section 1 Voltage regulation keying section The first section to build contains the voltage stabilizers for the different voltages and the keying circuit You begin with the components having the lowest building height mainly resistors and small capacitors al R24 27k Here follows a small capacitor with the marking 104 which means 100 nF Capacitors of type X7R are mainly used for blocking RF Their Q isn t good which makes them unusable for resonant circuits 03 August 200
35. creasingly giving power to the transmitter stages Through this slow increase of the supply voltage the maximum transmission power isn t reached till after some 5 mSec rounded flank After release of the key C69 is discharged via R24 with a time con stant of once more some 5mSec After reaching the gate opening voltage T3 will slowly reduce the voltage of the transmitter stages The output will reduce to zero within about 5mSec rounded flank Through the easy controlling by T3 it is possible to reach well defined flanks for the keying Key clicks are eliminated Voltage controller To reduce the effects of varying input voltage IC8 IC9 is used to regulate voltages for the individual stages The kits can work from any supply volta ge between 10 and 15 V The first steps What you need to know You don t have to be an electronics expert but you have to know some of the basics before you delve into this adventure The first steps What you need to know You don t have to be an electronics expert but you have to know some of the basics before you delve into this adventure Colour coding Resistors capacitors inductances You must be familiar with the standard colour coding of electronic compon ents If you re not sure measure with an ohmmeter Some 8 of the male populations is red green colour blink Many doesn t even know If you are one of these you should measure all resistors with an ohmmeter before mounting them
36. diagram a circle marks which side the resistor is supposed to stand on 311 R10 560R R11 18k S R12 18k R14 22k 3 Now follows the film capacitors The WIMA film capacitors are non polari zed and can be placed either way It is good practice though to mount lt them with their text side visible RM5 means 5mm spacing 211 C28 0 01pF film RM5 C29 0 22uF film RM5 e C30 0 01uF film RM5 C32 0 047uF film RM5 Now the diode in plastic casing mind the cathode ring 05 1N4004 or equal Now follows a new component the integrated circuit TDA7050 in DIP casing Because of the production process the lead of such an IC are always bent a little outwards To fit the IC to the pc board you will have to pre bend the leads a little To do that you roll the IC on a flat surface till the leads are at a right angle with the casing as shown in the picture Pin 1 of the IC is found by the markings on the top of the IC You ll find either a notch or a dot The placement diagram shows the position of the notch The IC is mounted in the pc board and initially two diagonally placed leads are solder to position the IC i Check if the IC is flat onto the pc board Correct if necessary Then solder the rest of the leads IC3 TDA7050 The three electrolytic capacitors should be placed carefully Now what was this thing about electrolytic capacitors Right the long lead is the positive termi
37. ds When you have found the signal trim C98 and C96 to maximum field strengh the receiver C98 C96 the capacitors in the band pass filter When properly adjusted the local oscillator frequency is let through and other mixer products are suppressed If no 8 5 MHz receiver is on hand you will have to trim the filter with the help of an oscilloscope or an RF probe You can easily build a very simple RF probe for a multimeter RF Probe 1N4148 2 test point lt t 01 Multimeter To pc board ground i Multimeter Solder to diodes and to capacitor to a piece of pc board or free on end as shown in the drawing If you have it you can change the silicon diode to a germanium type The probe will be more sensitive then When the probe is connected between test point C79 and the multimeter you can directly measure RF The display is not directly calibrated in mV but for us it suf fices to see whether any RF is present or not The main disadvantage of such a simple probe is that it is not very selective you may fail and adjust the circuit to a wrong mixing product If a trimmer has reached its maximum the only solution is to remove the corresponding coil and re wind it with an extra turn If the trimmer is at minimum you will correspondingly have to remove one turn The drawing shows the minimum position Appendix E 37 Test section 5 Visual inspecton 2 Resistance test 3 Smoke
38. eeds 23 turns the secondary 8 To place the secon dary symmetrically we need to count INSIDE the ring 23 divided 3 el by 2 is 11 5 the center thus is at AM gt 11 5 turns The 8 turns of the w secondary should be made as 4 plus 4 before and after the 11 5th ak turn The half turn is impossible as each turn put through the ring V De is an entire turn We must accept a slight assymmetry and must decide for 11 or 12 as center 11 minus 4 equals 7 so the secondary should be started on turn 7 In the picture is shown a coil of 14 turns with a secondary of 4 turns Half of 14 is 7 minus one half of4 gives the start of the secondary at turn 5 of the main coil That is you see 5 turns of the main coil before and after the secondary WARNING In the kit the numbering of coils are not the same L2 and L3 have the resonant coil numbered 1 and 2 This sounds a lot more complicated than it is When you have done it once it becomes quite easy 16 That much about practical things In the next section I will tell those of you who want to understand your Sparrow about the calculation of the coils The band filters and resonant circuits in the Sparrow are all parallel resonant circuits as L SQ Shown to the left of the example from the front LT eweze3 end As toroids are not variable we must work b with variable capacitors The total capacity will be calculated as shown
39. ep 8 80m C91 c90 Wu Bop T 1501 C39 Output oh 10p 4820 6V wi uL BF244A Ampl U ke D11 y 1 41C5 4 RX Input 8V 5V6 U key D13 LO 100 C52 2 R36 mVss BA479 Es C70 Dr 2 33nF C7 L10 L11 L12 R27 gt MET III 58 BF199 L8 2N2210A Tr 4 A 1 V HT pt 216 C76 674 cad 581 ced 50 120p C53 UN I QN x 470p 560p 560 560 560 470p I33p 8 C61 2 8k2 m HI Tes 214 E 22n Er R32 R33 83 C67 R29 47 4148 oF IRON gt 47R N Abgl 4 915Mhz I la bi ca TX Output Filter 2 Dr 3 TX Output adj tot 47uH 47uH ve 2k5 12 Teru ioon PA 03 12 2002 SOLF DK1HE ge ndert 7 3 03 DL2FI TX Mixer Ampl Driver E 32 2501969 T AJ 11 2501969 L p L Tr 2 FT50 43 primary 4 turns isol mounting wire secondary 7 turns 0 5mm copper wire on the larger black toroid 9 fe BR Begin with the secondary Begin from the back forwards winding counterclockwise 7 times through the ring Then the primary the moun ting wire from behind forwards through the ring SFr 12 2082 Section 8 PA R35 47R 012 1 4148 C71 left out C72 100nF 1 C73 1 63V MKS2 RM5 C68 22nF Dr 4 RFC 47 FT37 43 11 turns 0 5mm copper wire on the smaller bl
40. good as decoupling capaci 18 tors when some component RF wise should be grounded but not DC wise Values between 1nF and 100nF are the most common Those who order capacitors them selves or salvages them from old gear have to be very careful which capacitor is used for what purpose In kits you don t have to worry that much the developer and QRPProject has made the choice Revision 03 August 2005 Revision 03 August 2 The DDS VFO for the Sparrow In the next section we will build the DDS VFO Those who ordered it ready made will probably want to read the description and user manual anyhow to be able to use the VFO afterwards Our QRP friend Steven Weber KD1JV from the White Mountains of New Hampshire is a proponent of a philosophy much like the DL QRP AG When you can find an equally good cheap solution you prefer that one He has created a DDS stage which can be used for any VFO in the interval 100 kHz to 9 5 MHz He doesn t use any expensive components and no expensive high frequency oscillator On my wish he has given over the project to DL QRP AG for our members to have access to a cheap DDS VFO in kit form The firmware has been modified a little for the Sparrow Functions of the DDS VFO 2 485 MHz to 2 585 MHz DDS mixed with 11MHz Xtal gives the local oscillator coverage from 8 415 MHz to 8 515 MHz Mixed with the IF of 4 915 MHZ that will give an RX TX frequency of 3 5 to 3 6MHZ Starting frequency 3 560 pre
41. he Sparrow without the meter or short is regulated down some 60 dB Hook up the volume potentiometer and the head phones When touching MP5 with a screwdriver with volume control turned up you should head som growling short wave in the head phones In RF poor areas you might need a piece of wire This test shows that the IF amplifier BFO and AF preamplifier all in IC2 works If you don t hear a thing repeat visual inspection At MP6 the hand test won t suffice Here you will need a 4 MHz signal The crystals are chosen to within 50 Hz but the other components might pull Revision 03 August 2005 August 2005 Revision 03 them a little Test 2 Method 1 If you have a transmitter tuneable to 4 MHz connect it to a dummy load Couple a piece of wire to MP6 as an antenna Don t solder it It gives too much trouble to clean the hole up later on Just put in a cut lead from a resistor in the hole and solder the wire to that By hanging obliquely the lead will have sufficient contact to the board Test 2 Method 2 If you have got a transmitter or signal generator then you can build a small test oscillator and use the other 4 MHz crystal for that The signal of this generator suffices for the functional test QRPProject sells a small RF gene rator kit for this purpose ordering number SignGen The diagram for a test oscillator and the signal generator is found on the CD Test 3 Method 3 This method not only tells whether the IF work
42. high capacitance C26 tantalum C24 yFtantalum To the right above the IC socket is the place for the film trimmer that is going to be used to trim the BFO Careful when soldering The plastic melts easily C94 trimmer 7mm 2 5 50pF black The diodes D3 and D4 are germanium in glass casing Be careful when bending the leads the glass casings break easily Both diodes should be mounted standing you ll need to bend the lead on the cathode side the one with the band very carefully back along the body of the diode The diode should be mounted where you find a circle in the placement diagram 23 tantalum P I 9 MU 99 2 n i DK HE I SPARROW 12 2882 iade i DL ORP AG AA143 bent end cathode AA143 bent end cathode 1 03 D4 For section 3 youll find 5 crystals Q1 to Q5 marked 4 915 MHz in a sepa rate bag These Xtals should under no circumstances be put together with other 4 915 MHz crystals The reason to be able to build a steep narrow filter the crystals have to be selected as sets The crystals were checked and paired at QRPProject and belong together WARNING When soldering the crystals capillary effects can pull up enough solder to short out the leads under the crystal If underlay spacers are found in the kit use them but we have delivery problems If no spacers are found mount each cryst
43. ide of the pc board you should be able to hear the DDS VFO on a receiver The initial frequency is 8 030 MHz with the shaft encoder the VFO should tune from 7 995 MHz to 8 100 MHz Prepare J1 In the kit you will find the connector and several crimp 2 contacts As nobody has the special crimp tool for the little contacts we will solder the wires on to the contacts For that purpose the wire should be 5 put in the upper part of the contacts and the upper part of the contact n 03 August 2005 Revisio Revision 03 August 2005 should be pushed together witd a pair of pliers Then the wire and contact is soldered with a LITTLE solder The contact is pushed into the connector till the little notch locks so that the contact won t pull easily out of the connector Test the VFO as described in the appendix When everything works we will build the heterodyne mixer that shall give the local oscillator frequency in conjunction with the DDS 23 8V Counter 91 Fa c90 E Output 10 10p D 1 1 244 24 50p 1504 C39 4915KHz IF Filter C11 Q3 04 c45 12 220 2505 12 Band XTAL 11MHz 23 520 LI HI IF Amp Dem BFO VCA C94 CTA C14 1500 60 33p 4915KHz C BFO 11592 6V C20 22n FS Meter DK1HE Monoband TRX AGC Peak Det S PARROW C2 D4 AA119 d 33u 5
44. iously Even expert solderers see a bent lead or a splash of solder creating a short And missed soldering points isn t less unpleasant More often than you would think a component is neglected and not soldered in Check also for the correct parts in the correct places Are electrolytic capacitors polarized correctly Diodes 2 Resistance test Measure with and ohmmeter the resistance between plus and minus on the pc board It is OK as long as there isn t a short 3 Smoke Screen test If the Sparrow passed the resistance test you can apply power It is wise to use a regulated supply with a current limiter Before connection the power supply the current limiter should be set for a minimum At this point it is stressed that the power supply always should be turned on first the apparatus under test afterwards This is general not only for kit testing The reason When turned on many power supplies present a brief voltage peak which can be large enough to damage the apparatus under test When the Sparrow is connected to the power supply you will keep one eye on the power supply and one on the pc board If smoke rises you ve got a pretty good indicator of malfunction same is true for currents above 10 mA The protection diode D10 is coupled so that wrong polarity results in a short 4 Measuring voltages MP 1 Should be 8V against ground MP 2 Should be 6V against ground MP 3 Should be 8V against ground 0 V when the key co
45. nal 31 10uF rad 33 100uF rad C34 47 rad R41 108 Last mount the to connectors Marking Headphone connector Volume potentiometer connector C105 100nF shown in the diagram shouldn t be placed till the defini tive mounting of the headphone connector where it should be soldered directly to the connector Now after finishing the work and visually inspecting please turn to appen dix B for test 11 12 IF Amp Dem 8V 4915KHz IF Filter 120R cas T AGC Peak Det 1100 100 100 C11 04 c45 IHE LZ pe Anali F 339 14 56k R13 Earias 5 Es AGC AA119 IC2 C94 n 150 a i up A244 TCA440 C20 pl 99P ki M Q 4915KHz c em Bro 1159 18k FS Meter 33nF DK1HE Monoband TRX SPARROW 6V min 32 Ohms Earphones C105 47n AGC A T I 8c AMP TDA7050 ou ar 0 01 EJ AF Final Amp 2k2log 6V 03 12 2002 SOLF DK1HE ge ndert 7 3 03 02211 Revision 03 August 2005 e Lee r steer 0705 988 299 2 8 ese 99 _ SPARROH SOLF 12 2882 bese e DL ORP AG Section 3 IF amplifier We begin once again with the resistors R3 220R R4 18k R5 120R R6 2k2 R7 56k R8 27R R9 1k5 R13 470R gt Then follows few capacitors of ve
46. nnector is groun ded Is a voltage is missing repeat the visual inspection When all is OK conti nue with section 2 Appendix B Test of section 2 1 visual inspection 36 2 Resistance test 3 Smoke Screen test 4 Functional test Connect a pair of head phones to the connector marked Earphone Best with the wires of the 2 pole pc board connector soldered to the earphone socket Don t shorten the lead for now save that for fitting in the enclosure Solder the volume potentiometer on to the 3 pole pc board connector as shown in the diagram The Test When you touch the middle connector of the volume potentiometer you should hear a loud humming maybe even some broadcast radio The latter is dependent on how near you are to the closest broadcast transmitter and how many antenna wires you have in your shack The more RF in the room the more broadcast you hear The same goes for MP 4 remember though that the volume is dependent on the volume potentiometer setting If you have heard the hum go on to section 3 If not repeat the visual inspection obviously you have a bad soldering or a misplaced component Appendix C Test of section 3 1 Visual inspection 2 Resistance test 3 Check if IC 2 is placed correctly in the socket 4 Smoke Screen test Functional test Hook up a field strength meter 50 100 mikroampere meter or a short to the pc board connector marked FS Meter This is important as the IF of t
47. nt and thus the amplification of the section The collector of T4 is loaded by the parallel resonant circuit of L8 C62 high 0 is achieved through a weak inductive coupling and thus a high increase in spectral purity of the transmitter signal C63 couples the amplified transmitter Signal to the following buffer T5 works as a emitter follower with high input impedance and thus low loading of L8 C62 The low impedance output of T5 is directly coupled to the base of R30 R31 places in class B operation kleiner Ruhestrom 5mA The dynamic amplification of the stage is determined by the feedback circiut of R34 C66 R33 Tr1 trans forms the output of T6 to the very low base impedance of the PA transistor T7 5 Ohm C68 D12 gives a better dynamic range of T7 for not quite sinus shaped signals clamper R35 places T7 in class C operation Tr2 transforms the collector impedance of T7 to the 50 Ohm level C71 serves as compensaton of the inductive reactance of Tr2 which is not negligeable in higher bands This increases the efficiency of the stage Harmonics are reduced by at least 50 dBc in the three section output filter of L10 L11 112 Transmitter keying and RIT RIT and XIT fine tuning of the transmitter by fixed RX frequency is achie ved directly in the DDS VFO The transmitter is keyed softly via T3 as fol lows 69 is charged via R24 with a time constant of some 5mSec On reaching the gate opening voltage conduct in
48. o using even the most expensive box it gives at feeling of going back to the roots of ham radio Available kits are roughly of two kinds 1 transcievers designed use and a minimum of complexity and component count 2 Monoband transcievers with a more demanding technique and larger complexity but with a comfort of use and performance comparable to more expensive equipment Kits in category 1 usually have direct conversion or single conversion recie vers Many of these are good constructions though They often miss sensi tivity and as their oscillators often are based on VXCOs they usually have a small frequency variation Due to little RF selectivity they often have intermodulation problems from BC transmitters on the 40 meter band RF attenuator potentiometers relieves this a little but at the price of reduced sensitivity No or bad AGC forces the operator to adjust the AF output volume Because of the increasing demands on the construction most kits are not offered in version for higher bands than 20 meters Kits in category 2 take more time to build due to a larger component count and more complex design Trimming of these kits are also more complica ted Many newcomers won t build one of these kits as they want to be QRV quickly and easily These categories of kits have in common that about 80 come from english speaking countries why and thus offers a problem of high im port and cu
49. programmed MHz Tuning The frequency of the VFO changes on turning the knob according to the preset tuning rate The frequency gets higher turning clockwise Choice of tuning rate A short push on the VFO tuning knob shifts tuning rate There are 4 Tuning rates Step1 10Hz Step2 30Hz Step 3 100Hz Step 4 1000Hz The chosen rates are acknowledged by blinking of the RIT LED Step4 4times Dlinking Step 3 3 times blinking aso At power on the Sparrow DDS start 5 with Tuning Rate 3 100 Hz step followed sequential by 30 Hz 10 Hz 1 kHz and then 100 Hz again every time you touch the shaft 5 Showing the band edges When the VFO is at its lower or upper edge the LED blinks Otherwise it wouldn t have been possible to tune to the band edges with any other rate than 10 Hz In the Sparrow only the RIT LED 15 used RIT R eceiver I ncremental Tuning The RIT is activated by the RIT switch and the RIT LED shows if it is on On using the tuning knob only the recieving frequency changes The tuning rate corresponds to the one chosen before activating the RIT but can be changed by pushing the RATE knob On switching off the RIT the previous tuning rate of the VFO is restored XIT X mitter I ncremental Tuning When activating the XIT the reception frequency remains unaltered but the transmitting frequency is changed Activate XIT by pushing the Memo switch when the RIT is activate CW keyer The VFO has an
50. r the enclosure when drilling to avoid pull out Drill the front and back according to the drilling guide test all components in their respective holes to find any errors Fix the pc board in the enclosure with the 8 mm standoffs and the short M3 screws Fix the potentiometers connectors and switches according to the diagram below Don t forget the external components shown ind the dia gram Cut the wires to the 2 and 3 pole connectors neither are too long or too short to fit The fuse socket will be best fitted above the PA transistor on the back wall Put in the DDS VFO with the 20 mm stand offs and the long M3 screws in the position front right Connect all connectors and power and repeat the tuning of all trimmers Set the output properly with the potentiometer P5 ts list for mounting in enclosure 1 Sparrow enclosure 1 Potentiometer 2k2log Volume 1 Stereo connector headphone 1 Stereo connector keyer 1 2 1mm coaxial power connector 1 Switch SPST RIT 1 Power switch SPST 1 Fuse socket 1 Fuse 1A 4 Stand offs 8 mm 1 stand off 20mm 4 Screws M3x5 1 screws M3x25 1 1kO0hm 2 100nF Below the enclosure you will fit 3 rubber feet To front one back 4 feet makes the Sparrow wobbly Par 35 Appendix A Test for section 1 1 Visual inspection As the first test all section should first be inspected with a magnifying glass for shorts Take this test ser
51. ry high Q the capacitors for the crystal filter Here we use either ceramic capacitors NPO multilayer capacitors it 15 not a matter of temperature coefficient but only the Q C11 220pF NPO C12 220pF NPO C13 220pF NPO C14 220pF NPO 211 C15 220pF NPO on C18 and 19 belongs to the oscillator of the second mixer and should also be either NPO or COG capacitors C18 150pF NPO C19 150pF NPO The following four capacitors are plain X7R decoupling capacitors C16 22nF 20 22nF C25 100 22 100 C17 is for trimming and is only necessary if the BFO can t be pulled far enough and should thus not be mounted now Before continuing with the electrolytic capacitors it is a good time to mount the socket for IC2 We use a socket here as large ICs are difficult to unsolder and the socket gives us a better chance Mind the notch on the socket which should face as in the placement diagram Again Solder in to diagonal corners check if the socket is flush with the board and only then solder the rest of the leads IC socket 16 pole flat Now mount the electrolytic capacitors mind the polarity C21 shouldn t be mounted yet Important C27 33uF 16V rad Now follows the tantalum capacitors as new components These are also polarized usually you ll find the value printed on the body and at one lead a PLUS sign Tantalum capacitors are used when focus is on low losses by
52. s but also tells about the quality of the filters Hook up a noise generator to MP6 and ground on the pc board A noise generator can be built quickly On the CD you will find a diagram and QRPProject sells a kit Order number RauschGen Hook up the head phone connector to the sound card of a PC on which you run an analyzer program Freeware GRAM is found on the CD The noise generator makes a broad band noise from 1 to more than 30 MHz The Sparrow IF AF as built so far will only let so much pass as correspon ding to the filter curve As the BFO translates this signal to AF the AF analyzer on the PC will show the pass band curve of the filter and AF Appendix D Test section 4 Visual inspecton Resistance test Smoke Screen test unctional test or this test we need the DDS VFO It should be connected to MP7 with a short piece of RG174 coaxial cable Please confer with the diagram to find the right point If everything has been built right the local oscillator signal is output to the Counter Output point on the pc board If you have a reciever capable of 1 2 3 working around 8 5 MHz hook it up to this point with either a piece of coaxial cable or a pair of twisted wires Search for the local oscillator signal on the reciever in the vicinity of 8 515 MHz 11 MHz from Band Xtal minus 2 485 from DDS 8 515 MHz Set C98 and C96 about center The center position is found where the screw point towards both lea
53. s till the soldering point is clean It can necessary to reheat the soldering point for the removal of the component Only heat the soldering point for the necessary time the copper foil can lift off from the pc board if overheated If this doesn t work you have to cut the component connector and pull it with a pair of pliers Contact DL2FI for replacement parts If you have to remove a transistor you are strongly advised to cut it on top of the pc board The 0 92 soldering points are especially small and attach ments are removed more easily one at a time without damaging the board After removal of the components the pc board holes are probably filled with solder Use a needle Heat needle and board at the same time till you can push the needle through the board Steel needle don t take the solder so the hole is freed If you don t know what to do Turn confidently to me This is easy by email to support arpproject biz by Revision 03 August 2005 Revision 03 August 2005 phone 49 0 30 859 61 323 To have an idea to whom you ar talking here s a photo of me DL2FI Peter known as QRPeter Ham radio operator since 1964 I have built and used QRP equipment for several years and am convinced the the great opportunity for ham radio is the rediscovery of home brewing My motto is Ham radio will be again when it is what 1 was Based on this conviction I founded the DL a work group for
54. stoms costs for europeans At the wish of the DL QRP AG I developed the monoband transciever described in this document to respect both the ease of construction of category 1 and the good technical specifi cations of category 2 Peter DL2FI dubbed it Spatz in english Sparrow Sparrow for small and awake Technical data 3 500 MHz to 3 600 MHz CW DDS VFO as stable as crystal control High RX sensitivity typ 0 3 High RX input selectivity good intermodulation characteristics on all bands 8 pole Cohn Filter with 400Hz bandwith Combined dynamic range of AF and IF of more than 90dB 05 RIT XIT Frequency read out in morse possible addition of an external frequency display with IF offset possible addition of a relative signal strength read out chirp reduction PA output adjustable to gt 5W hardy PA transistor 25 1969 direct monitoring of transmitted signal High suppression of spurious signals low power consumption RX 80mA TX 630mA at 5W Out reduction of external wiring through use of printed circuit connectors easily reproduced toroid inductances standard casing Teko CH2 with printed front panel sticker Description of individual stages Local oscillator The VFO is based on superheterodyne principles This is done by mixing the stable output of a DDS VFO with the output from a band set crystal oscilla tor This will give stable local oscillator operation even
55. used in the kits is sol derable That means that it burns or melts at solder temperature With thin wires till about 0 8 mm the heat capacity of a standard soldering iron suffices to burn of the lacquer For this purpose I touch the end of the wire with the soldering iron as close as possible to the toroid core and put on a lot of solder You should see a proper drop after a short while the lacquer disintegrates and smoke erupts It is advised to move your nose away the smoke is unhealthy When the smoke erupts move the soldering iron slowly towards the end of the wire till you have put solder on about 1 cm of the wire If it won t flow put on fresh solder The lacquer remains are pushed off by the solder When you are through check if the wire has solder all the 15 way around This is really important as most failures of home brew transci evers come from badly soldered inductors wound with lacquered copper wire With thicker wire you need to scrape off the lacquer with a knife Very carefully so that the wire isn t nicked and will break Do exactly the same to the other wire end and your inductor is ready You will often need a transformer These can be symmetrical or unsymmetri cal Symmetrical means without ground in this context No end of the coil goes to ground or decoupling capacitor Such symmetrical coils are built so that their turns lie centered over the main coll As an example take L5 from section 4 The main coils n
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