Manual 20m version August 8. 2005
Contents
1. 5 2 e e 5 5 5 D lee j e ie DK HE SPARROH SOLF 12 2002 120 es esse 6 89 Qoo Section 3 IF amplifier We begin once again with the resistors 2208 R4 18k R5 120R R6 2k R7 56k R8 27R RO 1k5 R13 470R Then follows a few capacitors of very high Q the capacitors for the crystal filter Here we use either ceramic capacitors or NPO multilayer capacitors Here it is not a matter of temperature coefficient but only the Q C11 220pF NPO C12 220pF NPO C13 220pF NPO C14 220pF NPO C15 220pF NPO m m C18 and C19 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 C20 22nF 25 100 C22 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 12. 11 R5 10k 02 2N3904 33 35 111 R8 470R R6 68R 22011 PP 11 1 C15 33pF R7 22k 3k9 R3 M C14 10n 100uF C21 10nF R9 68R 220p Ed C16 10nF 23 10nF 10n C9 11 C22 10nF C17 10nF 2 24 12 A C11 22pF C12 22pF 11 C18 10nF P BEWARE modification 7 470pF from PIN 10 the processor to ground and 10 kOhm from PIN 1 to PIN 20 not 4p7 as shown in the photo R6 68R C15 33p ai 22k CM L3 100p ia C21 M R9 68R 81 RF out EE E C16 10nF 21 Bestuckung Mini DDS VFO nach KD1JV Oberseite Version Spatz Mods DLZFI U1 Pin 22 a ee DL6DSA 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 Prepare J1 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 C19 22uF R10 220R C20 100nF R1 220R connection wire for RIT LED connection wire for Rate switch ma r re er c r p p rmm LI LII 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 conne
3. Peak Det L R6 100n 100n 19 TN OA O FS Meter 2k2 R24 27k CBS 33nF RX Input DK1HE Monoband TRX SPARROW V min 32 Ohms Earphones C105 47n 1N4004 C3 TDA7 050 R14 22k 228 100 Volume 1N5402 100n L 03 12 2002 SOLF DK1HE ge ndert 7 3 03 DL2FI Revision 1 0ct 03 Revision 1 O0ct 03 SOLF 12 2002 Section 4 VFO Mixer and counter read out R19 R37 C50 C44 C41 C39 C36 C37 C91 C98 ma BE L L L L L L e L R16 2k2 Dr 1 left out 45 10nF C40 left out 47K 100K 100pF 47nF 120pF 330pF 47pF 22nF 10nF ceramic trimmer 10 30pF Le LLLA LLLI LLLI Lt LLLI LLLI R18 R17 R15 R38 C89 C46 C42 C43 38 35 C90 C96 47K 2 0K 1k 1K 22nF 22nF 82pF 82 47pF 8 3 00000000 0000000 00 249 LOI LIL T 28 095 r i 24 sees ele Aa Wl r x ORE 4 1 1 2 41871 i M p IZ J o da P D DK1HE SPARROH DL 0RP AG 330pF NPO 10pF ceramic trimmer 10 30pF DR1 left out L 4 is a simple one layered coil with 0 3mm copper wire
4. min 32 Ohms 470R 05 AGC AAN9 Earphones HI d 001 655 1194004 28 0401 cin AGC Amp 5 H cl M 100p R41 R11 C20 5 33p a5 C18 22n RX Mixer 4915KHz CO LO 500mVss Bro 115 C34 1085 R14 7 6 22k 4 12 CZ C32 26 E TEE P ls p ul O R ro EN 5608 L Final Superheterodyne VFOc Ro oom AF Final Amp C35 m Volume PA 30p Baugruppe 6 20m BF244A Counter C31 T3 C90 NA Output 10n s R38 R37 330p BF244A Ampl ae 11MHz U key d Band XTAL EN I 5v6 C64 m C65 LO 100mVss C52 Dr 2 110 111 112 76 C77 78 csof csi caa C83 22 220 4 915Mhz 25 l TX Output Filter Q8 22k 03 12 2002 SOLF DK1HE ge ndert 7 3 03 DL2FI 28 Revision 1 0ct 03 Revision 1 O0ct 03 i i L 552 566 Ul LJ Ben x eb 250 852 r g5 s 2 sas SOLE 12 2002 eee C 1 3e Section 6 TX Mixer up to the input of T4 p rm rrr rrr ee L L LIII Ci 330R R26 18 R28 47nF 53 220 C55 56pF NPO C57 68pF C59 47nF C65 3 9pF ceramic trimmer 5mm 10 30pF ceramic trimmer 5mm 10 30pF CAL RE RT MP SPARRO
5. BA479 OOuF 100n R6 IF Amp Dem BFO VCA cas DK1HE Monoband TRX SPARROW AGC Peak Det 100 C11 C15 2k2 j T ML 6V C12 L sex D3 R13 in 32 Oh 220R i 4 ms LI acc Earphones C105 47 C28 0 01 E c94 5617 AME AGC Amp cl 4 a C20 R41 Q5 F 10R C19 22n RX Mixer 4 9152KHz Lo s00mVss BFO 22k 4 c29 1 R12 26 185 9 lo 22 0 010 0 047 Ooty bo Superheterodyne VFOcss 7 0 560R k AF Final Amp 221 2k2log C35 330p P Volume PA C36 4 C44 R18 m 47 47k r _ 20 T BF244A C98 538 3 Fa DDS VFO input 1 _ 91 pur su L cao M Output 10 6V 244 06 11 U ke Dr 1 EB o I u Band XTAL wem C64 99 LO 100mVss C52 Dr 2 L11 2N22104 8 IC6 3 SA612 C66 R33 fm 1 105 Driver 220p 4 9152Mhz 5 I TX Mixer R26 22k 44 Cn 78 C79 cso cai 1 123 52 2 20 80 20 80 00 2 2 4 R35 ee 012 if C72 C73 100 47n 1148 TX Output Filter 1 Folie 0 3 Dr 4 C92 C74 12 03 12 2002 SOLF DK1HE ge ndert 7 3 03 DL2FI Revision 1 0ct 03 Revision 1 O0ct 03 lt 16 2 14 0 14 1MHz Serien Tiefpass m Resonanz
6. Mseveral years and am convinced the the 6722 for h di he redis great opportunity for ham radio is the redis covery of home brewing My motto is Ham Zdradio will be again when it is what is was Based on this conviction I founded the DL QRP AG a work group for QRP and home brew in 1997 Since then the group has grown to more than 2300 members who have developed several excellent pieces of gear adding to the international succes of QRP and 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 2k2 R24 27k BY CB9 33nF DK1HE Monoband TRX SPARROW Baugruppe 1 20m 03 12 2002 SOLF DK1HE geandert 7 3 03 DL2FI Revision 1 0ct 03 eG W i DK HE 8888 see SPARROW SOLF 12 2002 e m Doe 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 R24 27k Here follows a small capacitor with the marking 104 which means 100 nF Capacitors of type X7
7. Kerbe is flat onto the pc board Correct if necessary Then solder the rest of the leads 1 163 TDA7050 The three electrolytic capacitors should be placed carefully Now what was this thing about Punkt electrolytic capacitors Right the long lead is the positive terminal 1 C31 10uF rad C33 100LF rad C34 47uF rad R41 10R Last mount the to connectors Marking Headphone connector Volume potentiometer connector 105 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 14 IF Amp Dem DK1HE Monoband TRX BY 4915KHz IF Filter 11206 on oad SPARROW AGC Peak Det 01 a2 03 04 100n C11 C15 ml Jl D4 44119 C24 220 220 6 334 PU 220 1 250 i 2200 32 Ohms 470R n Earphones 119 C105 47 C28 0 010 C84 C17 C18 150p 1N4004 ry li 10 an 100 ur lt 20 63 22 4915KHz C 1 o nies gt nics gt Bro 1150 33nF 03 12 2002 SOLF DK1HE geandert 7 3 03 DL2FI mE 03 Revision 1 0ct 5 i 5 eo 5 m 08625065 a 2 gt Bs Pu
8. 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 coil As an example take L5 from section 4 The main coils needs 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 11 511 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 C3 x C1 C2 That much about practical things In the next section I will tell those of you who want to understand your Sparrow
9. 3 pole connector 47uF rad 560R TDA7050 ection 3 1uF tantalum 10uF tantalum 100uF 16V rad 100nF 120R 150pF NPO 18k 1k5 P pP n H N e Ul pmP pm P H HP pP P HP HP pP Ul gt n HB H HB DBR EPA HL H HP mB H H H Ui 220pF NPO 220R 22nF 27R 2k2 2 pole connector 33p as C17 see text 33uF 16V rad 470R 56k A244 TCA440 AA143 trimmer 7mm black IC Sockel 16 pole flat Pack 20 3 Crystal 49152MHz Crystal 4 9152MHz matched Section 4 PrP Hn nm WP HB n9 H n 100 100 10nF 10pF 1K 2 2K 22nF 47K 47nF BF199 BF244A NE612 SA612 Pack 20 4 82pF NPO 120pF NPO 330pF NPO 47 pF NPO ceramic trimmer 30pF 11MHz Crystal 137 6 yellow Section 5 1k 22nF optional 470R NE612 SA612 PIN Diode BA479 ZPD 4V7 150 2 rot Pack 20 5 56pF NPO 560pF NPO 2 2pF NPO 330pF NPO 150pF NPO RM5 180pF NPO trimmer green ceramic trimmer 30pF T50 2 red T37 6 yellow T37 2 red 10uH SMCC Uu e PPO O Section 6 18K 220pF COG 22K 22nF 3 3K 330R 47nF BS250 T092 RFC 47uH SMCC NE612 SA612 ZPD 5V6 Pack 20 6 56pF NPO 3 9pF NPO 1 68pF NPO P HH U HB HB H HB n HB no e 470pF NPO ceramic trimmer 30pF Crystal 4 9152MHz T37 2 red ection 7 100nF 10R 150R 2N2219A 33k 47uF SMCC 47nF 820R 8k2 BF199 two hole ferri
10. Knob 12mm cover for knob rubber feet BNC connector pc board copper wireo 3mm brass colour copper wire 0 3mm red copper wire 0 5mm copper wire 0 2mm RRP PPP E Ne HL HP HP H n H PPB nr N nof 333 0 5mm Packing list Sparrow Section 1 8 packs Peripheral parts incl PCB enclosure drillig guide front back bottom foile back front protectiv foil front back manual DDS kit rmm LLLI L LI L L Revision 1 0ct 03 1 0 03 Revision L 194128 iH IM G E L i AN a 2N3304 Od Spannungsregl er 3 ay T Extern 470p nach 10k Pint 220 r a 1 CEET 11 6 IN 4 Q o8 14V 21 2 ERLUDEH A c sc 3 ENCODER B a SIDE SELECT a 2 2 E Ps 5 L ia Se ee S bia 0 I 12 T C A 022 F 1 cari T m 3 d H A irs A L AYL D 67 1 OLD Oo CORP ma t n m C14 c2 AGMD FI k 1506 a aa Drehencader 005 Angaas Cri 2Hx5404 SNE E Draufxzicht CLOCK zs Appendix Schematic DDS VFO 43 R1 R40 Abal opt er coH key 22n 4 9152KHz IF Filter
11. about the calculation of the coils The band filters and resonant circuits in the Sparrow all parallel resonant circuits as L SQQ 6 0 Shown to the left of the example from the front LT end As toroids are not variable we must work ro with variable capacitors The total capacity will be calculated as shown 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 Cges C1 C2 C3 We solve further by multiplying on both sides with C3 C3 C3 1 Cges C14 C2 Then multiply by C1 C2 C3 x C1 C2 0034 01402 C ges And the multiplication with Cges C3x C1 C2 Cges x C3 C2 C1 Then only the division by C3 C2 1 is left and Cges is ges 2401 Revision 1 0ct 03 When the total capacity is known we use Thomsons formula to find the necessary inductance for the given frequency LImstellen der homsonschen schwingungsfon 1 2 TT m C 1 Mutliplikation mit Wurzel L C 1 x Vic 2 TT 2 Division durch f Lc
12. 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 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 1 0ct 03 e O 1 0ct Revision 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 my wish he has given over the project to DL QRP AG for our members to have access to a c
13. while measuring 1 View of the bottom T6 2N2219A with underlay 1 L8 toroid 137 2 red 20 5 turns 0 3mm copper wire reduce secondary windings if too much output Dr 3 RFC 47g H SMCC L Tri Two hole core 4 NS primary 5 turns 0 2 mm copper Tr wire secondary 1turn 0 5mm cop per 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 a R1 R40 RX Preselector C1 Abal opt IF Amp Dem BFO VCA 4915KHz IF Filter 7 DK1HE Monoband TRX coH 91208 1 v 21 c22 C25 Ukey m sns ree AGC Peak Det SPARROW 100n RB 100n C11 C15 2k2 Ra e 3 220 a HS 6 C12 22 2208 T 56k p E R13 min 32 Ohms 220 zd 1 05 i Earphones AGC 44119 C105 47n 4 1N4004 C28 0 01 c94 C17 18 1 AGC Amp i C20 R41 bp 33 R14 Q5 10R C19 22n 10 n RX Mixer 4915KHZ a LO 500mVss gro 39m 27R rq 29 2 2 1k5 I 15111 224 0 01p 0 047 O P4 Superheterodyne VF Qcss fo 5608 18k AF Final Amp 22n 2k2log C35 Volume C385 L4 PA 47 1 C96 I BY Baugruppe 8 BF2444 C98 38 20m ounter C91 Gb C90 47 2k2 C39 Output 10n 3 BF2444 Key Ampl Q6 11MHz T U key TI TI 8V R24 114165 RX Input Band XTAL
14. 1 Co C TO 3 Quadneren 1 ses 4 f 4 Division durch C 4 TT fe 3948 f C As shown we now only need the wished frequency and the freshly calcula ted value for total capacity to calculate the inductance for resonance Z The values for L f and are in Henry Hz and Farad that is quite unhandy 5 If fis in MHz and C in pF we can directly calculate the size of the induc 5 1 e Now we only have the calculation of turns for the toroid left The formula for powder cores looks like this l Lin WH 100 A entsprechend des verwendeten Kems r 37 2 A 40 uH gra 100 dg L T37 B A 30 pro 100 Wag the CD you ll find the small programm Mini RK with which such calcu lations 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 cushion 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 0 zeros 10pF 101 10 1760 10 0pF 102 10 and 2 zeros 10 00pF 1nF 103 10 and 3 zeros 10 000 10nF 104 10 4 zeros 10 0000pF 100nF
15. 5 6 C64 U key C69 LO 100mVss C52 CT 87199 Dr2 33nF 104H C75 L10 L11 L12 BS250 gt pm 2N22104 71 8 Tr 1 IC6 3 SA612 R33 m 108 105 Driver 220 4 915Mhz 25 L TX Mixer R26 32 25 1969 M qm 2 a 180 5 Ei Tr 2 012 C72 C73 100n 47n 4145 TX Output Filter 1p Folie Dr 3 Dr 4 con C74 EUN pem PA 03 12 2002 SOLF DK1HE ge ndert 6 4 03 DL2FI 1 0ct 03 Revision O 4 O O t gt 9 a 2 ssh LD x n e 527 EU 9 oe 606 77 DK1HE _ SOLF 12 2002 cmq DL QRP AG Section 8 PA R35 47R 012 1 4148 C71 left out C72 100nF C73 1 63V MKS2 5 C68 220 Dr 4 RFC 47uH on FT37 43 11 turns 0 5mm copper wire on the smaller black toroid BEWARE DR4 should be wound counterclockwise to fit the holes The power transistor 2SC1969 is more than enough for the Sparrow which makes it close to indestructible in this setup Here you will also have to take care in measurements as the collector is connected to the casing 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 th
16. 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 T37 6 yellow 17 turns 0 3mm copper wire 15 becoms a secondary As seen in the diagram this should be symmetrical ly wound on the primary It is important that the turns are wound in the 3 oe N IC4 NE612 SA612 T1 BF244A T2 BF199 T8 BF244A L C47 left out C49 left out 51 left out a mm B1 oA Q6 11MHz 32pF HC18U 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 is the primary 1 2 is the secon dary L5 Toroid T37 6 yellow 20 7 0 3mm copper wire C48 left out C40 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 R1 R40 RX Preselector C1 4915KHz IF Filter Q1 92 C11 2 Q Q4 220p T 220p C12 C14 3 220p 220p 220p 220R C16 m C15 22n 95 19 4915KHZ 150p RX Mixer 0 500 55 Superheterodyne VFOcss Cou nte r C91 O
17. be quite difficult io In this section you ll use one large 1N5402 in plastic as a protection against wrong connection of power 010 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 1 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 When all components are mounted please run through check of appendix A 9 10 DK1HE Monoband TRX SPARROW 6V min 32 Ohms D5 Earphones C105 47n m 1N4004 AGC Amp Ica TDA7050 R41 10R Volume Baugruppe 2 20m 03 12 2002 SOLF DK1HE ge ndert 7 3 03 DL2FI Revision 1 0ct 03 2 gt H 2 H e B E ee a HH 4 6019 9 es E 2 54 4 e Ex MP4 i D a DU 018 2900 e Y 9 Bo T gt as 2 2c Bee i 5 4 sa Du Y s i e e 4 ces 1 4 4 sa es t 5 7 Lee c es 474 4 i 2 e SPARR
18. 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 cor rect 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 The 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 connector is grou
19. reactance and will only load the antenna signal very little D13 with be conducting during transmission and will thus protect the receiver from high RF voltages The preselector consists of two capacitatively coupled parallel resonant circuits with a high Q This gives a good selectivity and increases the intermodulation characteristics especial ly in the 40 meter band 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 diode D2 and thus increase in impedance The signal can be further reduced the optional diode D14 To inhibit further intermo dulation 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 brea ie use Laid eee SF Lge ee re per eed As I E LTL prsi P L reception mixer 1 via 2 Weba IREME 1 4 Revision 1 0ct 03 Transmitter IC6 mixes the local oscillator signal with a 4915 kHz carrier The 4915 kHz Signal is produced by the internal oscillator of IC6 in conjunction with Q8 The following capacitatively coupled band pass filter based on 16 17 strips the unwanted mixer products C58 C59 transforms the high output impedance of the f
20. the wire used in the kits is solderable 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 the mounting it is not as the holes in the pc board are made for a specific 5 direction Each and every one of us should put the wire the way he wants But this forces a winding direction to have the proper geometry of the toroid If you put in the wire the back forward you must continue winding 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
21. tip regularly during work On ground areas you TE 9 might need a larger soldering iron tip Silber 0 01 Gold 0 1 Only heat the soldering point enough for a good connection A small vise for holding the pc board is a great help The printed circuit board is double sided and all holes are plated through This means that you need not and indeed should not solder on the compo nent side of the board How to recognize a good and a bad soldering GOOD BAD Ideal the soldering point Too much solder 15 rounded and concave has been added Touch pc board and component at the same time with the soldering iron Within one or 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 6 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 L flush too In other words components with long wires Please read the following before removing components from the pc board Oh 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 sold
22. when the wire passes through both holes 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 5 Wig through the lower to finish turn number two Don t pull the wire to ieu hard over the edges the lacquer 1 eas ily scratched Continue with turn three four and five and the primary 1s finished You still miss the secondary As the input of the PA tran sistor 15 low imped 5 Wig 02mm CuL 1 Wdq 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 TRI 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 is finished The transformer can be fitted The secondary comes as 4 3 the pri 5 mary as 2 1 L Tr 1 C67 3 H Revision 1 0ct 03 Revision 1 0ct 03 Packing list Sparrow 20 Section 1 0 033uF film 5mm 1uF radial 100nF 104 12V connector 1 5402 o 1 5822 27k 2 pole connector 47uF radial 78L06 78L08 2k2 ection 2 0 01uF film 5 0 047uF film 5 0 22uF film RM5 10uF rad 100 rad 100n 10R 18k 1N4004 or equal 22k 2 pole connector KH
23. 2nF C5 2 2pF C6 2 2pF AREER PGE Has BE tue Binz 111 4 tH LAT 23 I ors ae C7 56pF 8 22nF C9 150pF NPO C10 150pF NPO C70 22nF 76 56pF 77 120pF COG C78 330pF COG 79 56pFCOG C80 330pF COG C81 56pFCOG C82 120pF COG 83 56pFCOG C104 22nF optional C75 film trimmer green ma L L L LIII LII 97 ceramic trimmer 5mm 10 30pF C99 ceramic trimmer 5mm 10 30pF C100 ceramic trimmer 5mm 10 30pF L1 toroid T37 2 red 21 turns 0 3mm copper wire 1201014 T37 2 red 20 5 turns 0 3mm 1 AM gt copper wire BEWARE 3 4 secondary 3 should be wound a 50 2 ring the only 2 w larger red ring L3toroid T50 2 red 35 10 turns 0 3mm aby 4 copper wire BEWARE 3 4 secondary 19 RFC 10uH SMCC L10 toroid T37 6 yellow 16 turns 0 5mm copper wire L11 toroid 137 6 yellow 17 turns 0 5mm copper wire L12 toroid 137 6 yellow 16 turns 0 5mm copper wire eK ma Lat Lt LU When you have mounted all components go to the test in appendix E 21 RX Preselector R1 R40 IF Amp Dem BFO VCA s DK1HE Monoband TRX 4 4915KHz IF Filter uL ou Peak Det SPARROW Q1 Q2 Q3 Q4 OOWF 100n 100n 22 C27 D4 ns n av acm amu JB pu 14 Sr 03 R13 p 220p 220p r Abgliopt coH
24. 6 pole flat Now mount the electrolytic capacitors mind the polarity C21 shouldn t be mounted yet Important 27 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 high capacitance 26 10uF tantalum C24 tantalum 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 C23 1088 tantalum SOLF 12 2002 1 D3 D4 For section R SHIT IDA 2 m I BC JS 2 cr DK1HE TIRE i s SPARROH mg DL 0RP AG AA143 bent end cathode AA143 bent end cathode 3 youll find 4 crystals 01 to 04 marked 4 000 MHz in a separate bag These 4 should under no circumstances be put together with the other 4 MHz crystals The reason to be able to build a steep narrow filter the cr
25. 69 1 LO 100mVss C52 d I Dr 2 33nF L11 8 ICB 3 5 612 2422104 C78 79 C80 81 82 C83 C76 C77 UN p 82 Ip 220 5 5 Ei CBE R33 4 all TX Output Filter 108 105 Dr 3 220p 4 915Mhz 555 22k TX Mixer 92 C74 T 12V ioo 03 12 2002 SOLF DK1HE ge ndert 7 3 03 DL2FI Driver 30 1144004 C28 001 C33 Hil i 1 0ct 03 Revision ef ep vision 1 0ct 03 oc nw T L i 1 1 r 4 1 h 1 r3 L f x T a ume ah E ao 1i 99 6 LI a hd P 5 06 DK1HE SPARROW DL QRP RG R29 2k2 Trimming value R30 33K R31 8 2 R32 150 R33 10 left out if too much output R34 10 C60 47nF C61 47nF C62 100 63 12 C66 47nF C67 47nF 74 100 92 47uF careful about polarity 103 ceramic trimmer 5mm 10 30pF 4 9 1114 199 2 15 BF199 Ferrit bead on collector i lead Diagram left of BF199 note that it is not the I Ds standard EBC configuration 1 Callector 2 Emitter 3 Base Ferrite bead placed over collec tor of T5 The driver 2N2219 is in a T039 metal casing BEWARE the casing is connec ted to the collector and is on positive potential Here it 15 easy to short out
26. Another standard uses the decimal name of the power of ten as decimal point 1 5 1 5 pF 212 2 2 nF Often a J is used in stead of the for picofarad The J marks a capacitor with a 5 tolerance 100J represents 100pF 5 and 150J represents 150pF 5 17 The list of signs for tolerance are B 0 1pF 4 5 0 25pF K 10 D 0 5pF 20 x1pF if gt 10pF dann 1 S 20 50 2 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 uFarad 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 Q They are preferred i 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 fordel
27. D Arti DDS VFO m 7 915 8 015 MHz 14 000 14 100 MHz 14 000 14 100 MHz 14 0 14 1 2 LO Eingang Bandpass D RX Mischer Mischer 8 21 LO Xtal TX Mischer TX Regelstu lt 4 915 MHz C gt Quarzfilter gt LO Output 18 915 19 015 MHz Jr 4 515MHz 14 000 14 100 MHz A244D Tca ZF Xtal Mischer 71 4 515 MHz Regelspannung AGC Verst NF Verst 45 0 130 1 00151 94 46 0 PO T UOLSLADY 47
28. H DL QRP AG 22K 3 3K 22nF 220pF 3 9pF 470pF 47nF 1 L6 toroid 137 2 red 3 XT 20 7 turns copper wire 0 3mm N wn 1 2 are the coupling winding UN gt L7 toroid T37 2 red i IN NS 20 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 oppotite Dr2 RFC 47uH SMCC IC6 NE612 SA612 T3 5250 T092 011 ZPD 5V6 Carefully check marking don t confuse with 1N4148 08 4 915 MHz Crystal HC18U Go to the test in appendix F 29 Abgliopt 4915KHz IF Filter coH r ei IF Amp Dem BFO VCA D K1 ono ba n d T RX IH 4 T T U key 2an Basa PP Peak Det SPARROW 100n RB 100n 014 2k2 I l Z ME AA119 L3 Ab ak 220p T 6V JE SEN aq r min 32 Ohms H H 119 zi Earphones 1 C105 47n C94 C17 C18 C20 R41 s p 5 F R11 R14 Q5 10R 6 RX Mixer 4915KHz 7 a 200 LOo 500mVvss BFO 150p 4 R10 C32 28 eb 22n 2k2log C35 330p FS Meter Volume C38 L4 47 I C96 ev Baugruppe 7 Br2444 T 038 3 20 C91 Can C39 Output 10n apt 4 R38 R37 330p 44 100k x 2k2 BF244A crs Key Ampl 25 06 11 MHz 011 a T T BY R24 144165 8 Band XTAL 5v6 C64 C65 U key B C
29. OW SOLF 12 2002 a DL QRP 06 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 diagram a circle marks which side the resistor is sup posed to stand on R10 560R R12 18k R11 18k R14 22k Now follows the film capacitors The WIMA film capacitors are non polari 5 zed and can be placed either way It is good practice though to mount them with their text side visible An 2 C28 0 01pF film RM5 C30 0 01pF film 5 C29 0 22uF film RM5 C32 0 047uF film 5 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 al ways bent a little outwards To fit the IC to the pc board you will have to prebend 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 initi ally two placed leads are solder to positi on the IC Check if the IC
30. R are mainly used for blocking RF Their Q isn t good which makes them unusable for resonant circuits C93 100nF 104 Revision 1 Now come the electrolytic capacitors Please note the polarity the body of the capacitor you ll find minus marking and you ll find that the long lead is Ye the positive pole C85 1pF radial C86 1pF radial Hi 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 69 0 033 uF MKS Foil Cap 5mm Many small signal transistors and voltage regulators are made 9 in 92 cases The component placement drawings show all components basically from above When mounting please Pd note the direction of the rounded part of the casing Please do not mix up the two voltage controllers which are both in 092 the 8 V regulator is marked 108 and the 6 V regulator marked 106 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 IC8 78106 9 78108 The diodes have ring around their body to mark the cathode For diodes in plastic casing this is easy to see 29 BF Hathade but on diodes with glass casing it can
31. Revision 1 O0ct 03 DL QRP AG project Amateur Radio DK1HE Monoband TRX I T x Det SPARROW I gt T ALY m no 5 jPECTRUM ANALYZER HMSO Fitir GOLF DEIHE gadeden T 262 i Sparrow Monoband CW Superhet Transceiver 20m 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 Lowpa
32. 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 1 Visual inspecton 2 Resistance test 3 Smoke Screen test Functional test For 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 working around 11 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 19 MHz 7 975 MHz from the VFO 11 MHz from the band crystal 18 975 MHz Set C98 and C96 about center The center position is found where the screw point towards both leads Wh
33. ct the shaft encoder correctly If you connect a piece of wire about 10 cm to the point marked RF on the bottom side of the pc board you should be able to hear the DDS VFO on a receiver The initial frequency is 7 975 MHz with the shaft encoder the VFO should tune from 7 910 MHz to 8 020 MHz Resulting in an end frequency of 13 995 MHz to 14 105 MHz after mixing with Xtal Oscillator and IF later on In the kit you will find the connector and several crimp contacts As nobody has the special crimp tool for the little contacts we will solder the Revision 1 0ct 03 Revision 1 O0ct 03 wires on to the contacts For that purpose the wire should be put in the upper part of the contacts and the upper part of the contact 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 24 BF244A C11 220p Band XTAL AO DOE 1 11MHz 4915KHz IF Filter Q1 02 C sl J wy 220p C12 C13 C14 220R 220p 220p 220p C16 22n C84 C17 18 150p B BFO 150p 4915 Hz C ER 22 IF Amp Dem 8V ca pes cas
34. ction 6 1 Visual inspecton 2 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 18 MHz signal which stems from mixing the local oscillator with the 4 915 MHz crystal Now connect 8 to a receiver just as when tuning the receiver part of Sparrow This time the external reciever must be tuned to 14 060 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 1 0ct 03 Revision 1 O0ct 03 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 T
35. cton 2 Resistance test 3 Smoke 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 38 Appendix F Test se
36. e transistor and the enclosure grey silicone washer will fit over the screw and then CLOCKWISE 4 times through the ring 2501969 iG E 25 1969 Tr 2 FT50 43 primary 4 turns isol mounting wire secondary 7 turns 0 5mm copper wire on the larger black toroid 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 Now test according to appendix H 33 34 1511 Ben 100 2 1 Hohl Sicherung 100k 100n D10 auf Mainboard Ls 2k2 log RIT Schalter EarPh 13 8 VDC Kureschlussstecker oder FS Meter Spatz Mainboard RG 174 a ehemaligen amp nschlufs f r Keramik Resonator Siehe Detailzeichnung de Un D D 1 0ct 03 Revision 1 0ct 03 Revision 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 quides 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 ETT to the enclosure Allways put a piece of wood under the enclosure when drilling to avoid pul
37. en you have found the signal trim C98 and C96 to maximum field strengh on the reciever C98 C96 are 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 19 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 134148 2 pi To test point lt t 01 Multimeter 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 sentiti ve Ii only works with at least 0 5V RV voltage Better choice is the little linearized probe offered by QRPproject 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 37 Appendix Test section 5 1 Visual inspe
38. er 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 this till the soldering point is clean It can necessary to reheat the soldering point for the removal of the compo nent 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 10 92 soldering points are especially small and at tachments 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 Revision 1 0ct 03 Revision 1 O0ct 03 so the hole is freed If you don t know what to do Turn to me This is easy by email to support arpproject biz by 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 have built and used QRP equipment for A RE 1
39. est section 8 1 Visual inspecton 2 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 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 on 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 secondary of 1 turn Like in most other transformer diagrams you will find one end of a coil marked with a point This point AL WAYS 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
40. he 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 9 MHz signal The crystals are chosen to within 50 Hz but the other components might Revision 1 0ct 03 en 43 oc pull them a little Test 2 Method 1 If you have a transmitter tuneable to 4 915 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 not got a transmitter or signal generator then you can build a small test oscillator and use the other 4 915 MHz crystal for that The signal of this generator suffices for the functional test QRPProject sells a small RF generator 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 works
41. heap DDS VFO in kit form The firmware has been modified a little for the Sparrow Functions of the DDS VFO 7 915 MHz to 8 015 MHz DDS gives the local oscillator coverage from 18 915 MHz to 19 015 MHz Mixed with the IF of 4 915MHZ that will give an RX TX frequency of 14 00 to 14 100 MHZ Starting frequency is program med at 14 060 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 blinking Step 3 3 times blinking aso At power on the Sparrow DDS start with Tuning Rate 3 2100 Hz step followed sequential by 30 Hz 10 Hz 1 kHz and then 100 Hz again every time you touch the shaft 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 is 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 sw
42. ilter to the input impedance of the amplifier T4 P5 regulates the emitter current and thus the amplification of the section The collector of T4 is loaded by the parallel resonant circuit of L8 C62 A high Q is achieved through a weak inductive coupling and thus a high increase in spectral purity of the transmitter signal C63 couples the ampli fied transmitter signal to the following buffer 5 works as a emitter follo wer with high input impedance and thus low loading of L8 C62 The low impedance output of 5 is directly coupled to the base of T6 R30 R31 places T6 in class B operation kleiner Ruhestrom 5mA The dynamic amplification of the stage is determined by the feedback circiut of R34 C66 R33 Tr1 transforms 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 operation Tr2 transforms the collector impedance of T7 to the 50 Ohm level C71 serves as a 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 L12 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 C69 15 charged via R24 with a ti
43. is will give stable local oscillator operation even in the 6 meter band Below you will find a simulation of the entire 40 meter input circuit done with RFSIM99 The software is Freeware and is contained on the CD enclo On the circuit sed with the kit so you are free to play with the components The DDS VFO gives a 7915 8015 kHz signal stable as a crystal oscillator IC1 amplifies the received signal after mixing with the local oscillator and This is buffered in T2 and input to the Gilbert cell mixer IC4 where it is outputs the 4000 kHz IF mixed with an internal band set crystal oscillator signal based on Q6 In case of overtone crystals Dr1 with reduce the 1 harmonic On the output of the mixer a loosely coupled highly 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 spec tral purity of the amplified signal The local oscillator signal is sent by C9 or the divider 35 36 to the transmitter and reciever mixers respectively The optional JFET buffer T8 is for low loss coupling of an external frequency display Receiver The antenna signal goes from the transmitter output filter through the on series resonant circuit 75 19 to the RX preselector As the PA transistor T7 is blocked during reception class operation Tr2 is only active with its relatively high inductive
44. itching 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 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 speed the transmitter keying is disabled and the side tone oscillator will sound an A to give the user a feel for the actual keying rate Holding down the paddle will repeat the change till the upper or lower limit is reached This rate change is in steps of 2 WPM 10 cpm Memo There is one memory position One long push gt 1 s stores the present frequency in memory The RIT LED blinks twice to confirm if the RIT is off A short push switches between present frequency and stored freq
45. l 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 arts list for mounting in enclosure 1 1 Sparrow enclosure 1 Potentiometer 2k2log Volume 1 Stereo connector headphone 1 1 Stereo connector keyer 1 12 1mm coaxial power connector 1 1 Switch SPST RIT 1 Power switch SPST 1 1 Fuse socket 1 Fuse 1A 4 Stand offs 8 mm 1 1 stand off 20mm 4 Screws M3x5 1 screws M3x25 11k0hm 2 100nF Below the enclosure you will fit 3 rubber feet front one back 4 feet makes the Sparrow wobbly m 4 35 Appendix 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 seriously Even
46. me constant of some 5mSec On reaching the gate opening voltage T3 conduct increasingly 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 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 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 5 resistor has color bands BROWN GREEN and RED A 1 5 1
47. n 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 enclosu re 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 15 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 the Sparrow without t
48. n is done but STOP Look at your work and think about how you put the wire through the ring There are two possibilities You can put in the wiere from behind forwardly as girls used to sew or from the front backward For the RF is equal but for 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 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 L ca 200 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 fills about 270 degrees of as the edges are smooth But with ferrites this can pose a problem as the the ring That is about the maximum for toroids If you edges are somewhat rough are careful about this when you wind you won t need to pull the turns apart later on even though it to some degree is possible turns UG 2 1 Cut off the rest of the wire but not too close and solder the ends Whats best That s up for debate The lacquer on
49. of high import and customs costs for europeans At the wish of the DL QRP AG I develo ped the monoband transciever described in this document to respect both the ease of construction of category 1 and the good technical specificati ons of category 2 Peter DL2FI dubbed it Spatz in english Sparrow Sparrow for small and awake Technical data 14 000 MHz to 14 100 MHz CW or any other Ham band DDS VFO as stable as crystal control High RX sensitivity typ 0 3pV High RX input selectivity good intermodulation characteristics on 40 meters 8 pole Cohn Filter with 400Hz bandwith Combined dynamic range of AF and IF of more than 90dB QSK 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 a max of 5W hardy PA transistor 2501969 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 Th
50. oroid 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 QRP 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 the 40 meter Sparrow we use several types of toroids In the low pass filter T37 6 yellow in the band pass filters and resonant circuits T37 2 red except L3 where we use the somewhat larger T50 2 The PA RFC is wound on a FT37 43 and the output transformer TR2 also on the larger powder core toroid T50 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 tur
51. resistor 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 rounded flank After release of the key C69 is discharged via R24 with a p time constant of once more some 5mSec After reaching the gate opening voltage will slowly reduce the voltage of the transmitter stages The output will reduce to zero within about 5mSec rounded flank Through the 5 easy controlling it is possible to reach well defined flanks for the 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 on RF chokes reflect their value in microhenries Like 5 resistors chokes use two significant digits and a multiplier Example an RF 5 Farbkodierung choke with color bands RED VIOLET BLACK would have a value of 27 Soldering Hopefully this 15 not your first encounter with a soldering iron If it is or this is your first semicon ductor project read the following tips Toleranz gold 5 silber 1096 Multiplikator 2 Stelle 1 Stelle Farbe Vert Multi plikator 0 Soldering iron 1 7 xit Use a 50 to 80 W soldering iron if possible A 0 8 ae mm pencil tip is ideal Keep the tip clean Use a Aa moist sponge moist cotton cloth to clean the
52. simple transciever won t compare to 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 Fun transcievers designed for QRP 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 recievers Many of these are good constructions though They often miss sensitivity 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 redu ced 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 eng lish speaking countries why and thus offers a problem
53. ss Filter LPF 2 OTT RW UL 0 UO W PO LL S LLL LLL Lu O O O 0 WO O O N N OF 01 9 e Section 6 TX Mixer up to the input of 14 Section 7 Exciter and amplifier up to and including TR1 C86 Section 8 PA Wiring diagramm Sparrow Fitting in the enclosure Appendix ATest 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 1 0ct 03 e gt lt 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 DL2FI 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
54. te small Ferrite bead potentiometer 10k PT6LV Unterlegscheibe fur Transistor Pack 20 7 56pF NPO ceramic trimmer 30pF 137 2 12pF NPO ection 8 1uF 63V MKS2 RM5 100nF 1N4148 22nF 47R FT37 43 2501969 FT50 43 LH HB HB h mPB n HB Ur rnm mp HH H H B B U nmpP mPB mp mp 41 Parts list Sparrow DDS VFO 0 1 uF CERAMIC MONO 22 uF 10VSUB MIN 4x7 mm Diode 1N4148 LED red LED socket 3 3 V Voltage regulator 100 R 10 k 220 2N7000 92 MOSFET CLOCK 25 000 MHz CMOS CPU ATMEL A90S2313 PC10 shaft encoder Crystal 4096 kHz Transistor 2N3904 connector 7pol 7fach Crimp connector 0 1 uF SMD 0805 0 01 uF SMD 0805 100 pF SMD 0805 22 pF SMD 0805 220 pF SMD 0805 33 pF SMD 0805 100 uH SMD 1008 2 2 UH SMD 1008 10 k SMD 0805 22 SMD 0805 270 RSMD 0805 3k9 SMD 0805 470 RSMD 0805 68 R SMD 0805 2N3904 SOT 23 SMD DDS AD9835 BRS 4 7pFSMD 0805 extern pc board DDS PRP H HP H PP WP H P pmP pP P H HP P p p H HI PPP PP A N no Parts list Sparrow Peripheral Parts enclosure Stereo connector Micro switch 2 1mm power socket 2 1mm power jack Schalter 1 x ein Fuse 1 25A Fuse socket 100nF 1 Potentiometer 2k2log Volume stand off 8mm screw M3x4 8 screw M3x10 nut M3 100k0hm stand off 20mm screw M3x25 front film back film protective film drilling guide bottom drilling guide front drilling guide back knob 30mm
55. uency The yellow LED blinks once when the frequency changes It starts on 14060 at power on When no memory frequency is stored the VFO will go to 14 060 MHz in stead AFA 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 15 abt 1kHz In RIT and XIT mode the AFA gives out the difference between IX 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 100uH SMD 1008 1 2 2 uH 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 243904 507 23 SMD 1 0 1uF CERAMIC MONO 1 20 22 uF 10VSUB MINATURE 4x7 mm Diode 1N4148 LED red 3 3 V Voltage regulator 100 5 1 4W 10 k 5 1 4W CARBON FILM 220 R 5 1 4W 2N7000 TO 92 MOSFET CLOCK 25 000 MHz CMOS 1 2 SIZE DIP CPU ATMEL A90S2313 PC10 programmed DDS ANALOG DEVICES AD9835BRS Shaft encoder Crystal 4096 kHz Transistor 2N3904 PC Board PRP H H HB POPP H mp Revision 1 0ct 03 Revision 1 0ct 03 1 AD9835 C2 100nF R4 270R C4 100p 1 C3 10nF C7 33pF L1 2 2yF R3 3 9k 5 220pF C9 10nF C1 100nF L2 2 2uF C8 33 C6 100p 9 C10 10nF C13 10nF 100p
56. utput 10 R3i 1k O T 6 11MHz Band XTAL 26 CI 22 891205 C25 479 v 224 225 9 ODuF IF Amp Dem 8V DK1HE Monoband TRX SPARROW AGC Peak Det 100n 100n min 32 Ohms Earphones C105 47 1N4004 IC3 TDA7050 C31 R14 C34 10 w 10 142 IC3 jr 10u 1 1 2 1 3 _ 07 6 22k C32 0 01p 0 0470 OH FS Mete r C95 C95 Volume 0 1 AF Final Amp 2k2log 1N5402 100n ET C8 L11 C C80 76 77 79 81 82 83 gt Ei 2 9 E E E TX Output Filter C C C 03 12 2002 SOLF DK1HE ge ndert 7 3 03 DL2FI 1 0ct 03 Revision Revision 1 O0ct 03 e ee Cr 4 21 2 Q eso o je JE B e 2 l Je T2 T K ipd 2m SOLF 12 2 2 e e ese e e 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 11s in the notch end of the IC 161 NE612 SA612 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 legible print Di PIN Diode BA479 D2 ZPD 4V7 013 PIN Diode BA479 014 PIN Diode BA479 optionals Then follows the capacitors 2110 22nF C2 56pF G 560pF NPO 2
57. ystals have to be selected as sets The four filter 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 crystal a small distance off the board A good trick 14 is 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 03 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 crys tals 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 162 Put A244 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 1 0ct 03 Small t
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