background image

 

 

The ‘Hilltopper-20’ Transceiver               K1SWL                                rev. 15 October 2018 

•  Install power diode D1 (1N5818) and bias diodes D6 and 

D7 (BAT85)

.  Be sure to match the 

banded end of the diode to that shown on the illustration. 

D7 must be installed before the 

Si5351 board is installed.   

•  Install electrolytic cap C43 (100 µF). This part is polarity sensitive. Install so the white band on 
the case faces the rear of the board. 

This also corresponds to the shorter wire lead.

 

 

•  Install U4 (78M05) This part is polarity sensitive. Install so that its heat-sink tab faces the rear 
of the board as illustrated. 

 

• Install capacitors C40 and C41 (marked ‘220’ or “22J”) and X6 (16.00 MHz). 

I use a narrow 

(0.1”) strip of paper under the crystal can to stand the crystal slightly above the board. Once at 
least one of the leads is soldered, the paper is removed.  

 

•  Install resistor R18 (10K ohm, brown-black-orange-gold) 

 

• Prepare the Si5351 board. Cut one pin off the 8-pin 
header supplied with the Si5351 and mate the 7-pin 
strip to the board.  

Save the cut-off pin.

 Make sure 

the insulated portion of the header is on the 
underside of the Si5351 board. Solder just one pin on 
the header strip.  Check your work to ensure the 
header strip is firmly and squarely seated on the small 
board.  Once it’s OK, solder the remaining pins. 
 
•  Install resistors R14 and R15 (470 ohm, yellow-
violet-brown-gold). 

 

•  Install the Si5351 on the main circuit board.  Place 
the cut-off header pin) under the edge of the Si5351 
board to ensure that the board is level.  Tape down the 
Si5351 board and the header pin using transparent 
tape. Flip the board over and solder one pin of the 7-
pin strip to the main board. As before, check your work 
and then solder the remaining pins.  Remove and 
discard the tape and single header-pin.  (Cut off excess 
lead length on the underside of the board.) 

 

• Install the 28-pin IC socket at U5.  The notch at one end of the socket faces the rear of the 
board as shown.  If you install it backwards- leave it! The socket itself is not polarity-sensitive. 
 
• Install capacitor C24 -  470 pF (marked ‘471’) 
 
• Install 28-pin IC U5 (ATmega328P). This device is 
polarity-sensitive. The dot and or/ notch at one end of 
the device must face the back of the board. You will 
need to bend the IC pins gently inward to mate with the 
socket. The best approach is push the IC down on a hard 
surface to bend one 14-pin row at a time evenly. Once 

Summary of Contents for Hilltopper-20

Page 1: ...The Hilltopper 20 Transceiver K1SWL rev 15 October 2018 1 The Hilltopper 20 a compact 20M CW transceiver Offered by the 4 State QRP Group ...

Page 2: ... a notch to reduce the 2 nd harmonic content to FCC compliant levels Wave shaping Q4 is a P channel MOSFET rated for 2A continuous duty with proper heatsinking and is turned on when Q3 is on conducting current to ground Capacitor C45 serves to make the supply voltage rise and fall linear Rise time is 2 mS and fall time is 4 mS Note R17 R18 and R21 are insurance ensuring that the PA stage and suppl...

Page 3: ... uF electrolytic cap All resistors are 5 tolerance watt 2 R13 R23 4 7 ohm Yellow violet gold gold 2 R14 R15 470 ohm Yellow violet brown gold 1 R22 1 0K ohm Brown black red gold 2 R1 R16 5K potentiometer PCB mount 8 R2 R3 R11 R17 R21 10K ohm Brown black orange gold 2 R8 R9 22K ohm Red red orange gold 2 R4 R5 150K ohm Brown green yellow gold 1 R10 510K ohm Green brown yellow gold 3 R6 R7 R12 1 0M oh...

Page 4: ...re 18 45 cm length 1 21 magnet wire 24 60 cm length 3 Knobs 4 6 spacer unthreaded 4 5 8 6 spacer threaded 4 6 32 x 4 machine screw pan head 4 6 32 x machine screw pan head 1 8 pin DIP socket 1 14 pin DIP socket 1 28 pin DIP socket Assembly general notes A number of components are polarity sensitive all semiconductor devices and diodes and the three electrolytic capacitors Capacitors these days are...

Page 5: ...ne file or emery board Flat blade and Phillips screwdriver Schematic and Component Placement diagrams are provided as part of documentation package It is highly recommended to print a copy for reference during construction As you build you can check off each construction step as you complete them in order When you think you are done you can check the list to verify that all of the parts have been ...

Page 6: ...ons are highlighted below I n s t a l l a l l q t y I n s t a l l a l l q t y 1 5 0 1 µ F c a p I n s t a l l a l l q t y 1 5 0 1 I n s t a l l a l l q t y 1 5 0 1 µ F c a p a c i t o I n s t a l l a l l q t y 1 5 0 1 µ F c a p a c i t o r I n s t a l l a l l q t y 1 5 0 1 µ F c a p a c i t I n s t a l l a l l q t y 1 5 0 1 µ F c a I n s t a l l a l l q t y 1 5 0 1 µ F I n s t a l l a l l q t y 1 ...

Page 7: ...ly install 3 or 4 components then solder each and clip off the excess lead length Locations are highlighted below I n s t a l l a l l q t y 1 5 0 1 µ F c a I n s t a l l a l l q t y 1 5 0 1 µ F c a p a c i t o r s I n s t a l l a l l q t y 1 5 0 1 µ F c a p a c i t o r I n s t a l l a l l q t y 1 5 0 1 µ F c a p a c i t o r I n s t a l l a l l q t y 1 5 0 I n s t a l l a l l q I n s t a l l a l l ...

Page 8: ...or J2 I n s t a l l a l l q t y 1 5 0 1 µ F c a p a c i t o r s I n s t a l l a l l q t y 1 5 0 1 µ F c a p a c i t o r s I n s t a l l a l l q t y 1 5 0 1 µ F c a p a c i t o I n s t a l l a l l q t y 1 5 0 1 µ F c a p a c i t o r I n s t a l l a l l q t y 1 5 0 1 µ F c a p a c i t o I n s t a l l a l l q t y 1 5 0 1 µ F c a p a I n s t a l l a l l q t y 1 5 0 1 µ F c a p a c i I n s t a l l a l ...

Page 9: ...e of the Si5351 board Solder just one pin on the header strip Check your work to ensure the header strip is firmly and squarely seated on the small board Once it s OK solder the remaining pins Install resistors R14 and R15 470 ohm yellow violet brown gold Install the Si5351 on the main circuit board Place the cut off header pin under the edge of the Si5351 board to ensure that the board is level T...

Page 10: ...ed assembly sequence follows the illustration Install J3 and J4 Install Install U6 78L05 Observe proper orientation on the board I n s t a l l a l l q t y 1 5 0 1 µ F c a p a c i I n s t a l l a l l q t y 1 5 0 1 µ F c a p a c i I n s t a l l a l l q t y 1 5 0 1 I n s t a l l a l l q t y 1 5 I n s t a l l a l l I n s t a l l a l l I n s t a l l a l l I n s t a l l a l I n s t a l l I n s t a l l I...

Page 11: ...ocket faces to the right Install the NE5532P IC at U3 This part is polarity sensitive Ensure that the notch dot on the IC faces to the right Install capacitor C27 0022 uF 222 Install capacitor C26 820 pF 821 Install capacitor C54 01 µF 103 Install resistors R7 and R12 1M ohm brown black green gold Install resistors R13 and R23 4 7 ohm yellow violet gold gold Install resistor R8 22K ohm red red ora...

Page 12: ...orange gold Install resistor R9 22K ohm Red red orange gold Install capacitor C18 033 uF marked 333 Install capacitor C16 47 pF marked 470 or 47J Install capacitor C17 68 pF marked 680 or 68J I n s t a l l a l l q t y 1 5 0 I n s t a l l a l l q t y 1 5 0 1 I n s t a l l a l l q t y 1 5 0 1 I n s t a l l a l l q t y 1 5 0 I n s t a l l a l l q t y 1 5 I n s t a l l a l l q t y 1 5 0 1 µ F c a I n ...

Page 13: ...l i g h i o n s a r e h i g h l i g h t e d b e l o w i o n s a r e h i g h l i g h t e d b e l o w i o n s a r e h i g h l i g h t e d b e l o w i o n s a r e h i g h l i g h t e d b e l o w i o n s a r e h i g h l i g h t e d b e l o w i o n s a r e h i g h l i g h t e d b e l o i o n s a r e h i g h l i g h t e d b e i o n s a r e h i g h l i g h t e d i i i o n s a r e h i g h l i g h t i i o ...

Page 14: ... pF marked 151 Install capacitors C7 C9 and C11 100 pF marked 101 Install RF chokes L3 and L4 18 Uh Brown blue bands Install crystals X1 through X4 5 185 MHz As in the group 3 assembly a narrow 0 1 strip of paper temporarily stands the crystals slightly above the board Install diodes D2 through D5 1N4148 Be to match the banded end of each diode to the banded marking on the circuit board component ...

Page 15: ...49 220 pF marked 221 Wind 8 turns of 21 thicker wire on toroid L5 FT37 43 gray toroid Trim excess lead length to 3 8 1 cm Using a small knife gently scrape the insulation from the protruding leads The insulation will not melt when you apply a soldering iron i o n s a r e h i g h l i g h t e d b e l o w i o n s a r e h i g h l i g h t e d b e l o w i o n s a r e h i g h l i g h t e d b e l o w i o ...

Page 16: ...ease no scrambled turns Using a 10 piece of the 24 thinner magnet wire wind 12 turns on a T37 6 yellow toroid Prepare the leads as above and install at L6 Using a 12 piece of the 24 thinner magnet wire wind 14 turns on the remaining T37 6 yellow toroid Prepare the leads as above and install at L7 Install capacitor C50 470 pF marked 471 Install capacitor C51 270 pF marked 271 Install capacitor C52 ...

Page 17: ...d the panels Make sure the panels line up with the edges of the cover Caution side panels get hot quickly and can cause painful burns 6 Solder the upper and lower inside corners of the panels 8 pl total This adds considerably to the enclosure strength 7 Remove the elastic band and the top cover 8 Remove the top cover and set it aside 9 Install the controls pots R1 R16 switch SW1 and rotary encoder...

Page 18: ...screws through the holes and spacers Use a screwdriver first turning counter clockwise until you feel each one seat and then turn clockwise to tighten 13 Install knobs on the three controls using a small slot screwdriver on the setscrews Space the knobs slightly above the panel to prevent rubbing The tuning knob must be just high enough to allow the detent switch on the rotary encoder to function ...

Page 19: ...ration factor is calculated and stored in U5 s EEPROM That value is retrieved on subsequent power ups It s possible you won t find 5 seconds to be enough time for the calibration If that s the case remove and restore DC power The 5 second routine starts over allowing you to zero in on the correct frequency IMPORTANT Remove the jumper at the CAL location when this calibration is completed Remove an...

Page 20: ...opper while pressing AND HOLDING the Function switch Release the switch when you hear R Tap either key paddle within 2 seconds to reverse the paddles Do nothing and there s no swap Next you ll hear B Tap either key paddle within 2 seconds to choose Mode B Do nothing and Mode A is selected Most operators prefer Mode A You ll then hear an A or B to confirm your selection Your selections are stored i...

Page 21: ...The Hilltopper 20 Transceiver K1SWL rev 15 October 2018 21 Receiver Schematic ...

Page 22: ...The Hilltopper 20 Transceiver K1SWL rev 15 October 2018 22 ...

Page 23: ...The Hilltopper 20 Transceiver K1SWL rev 15 October 2018 23 Transmitter Controller Schematic ...

Page 24: ...A POP design influenced the design of the transmitter section He also graciously provided open source firmware which I proceeded to mangle for this project Thanks also to David Cripe NMOS who played an invaluable role with enclosure layout technical liason with 4SQRP and provided advice with component selection Dave Benson K1SWL 14Nov 2017 ...

Reviews: