EA3GCY ILER-DDS, Assembly Manual

Page 1: ... VFO DDS Page 1 ILER DDS V2 1 Assembly manual Last review February 1 2018 ea3gcy gmail com Latest updates and news www ea3gcy com Thanks for purchasing the ILER DDS VFO kit Enjoy building QRP 73 Javier Solans ea3gcy ...

Page 2: ...UILDERS 4 PARTS LIST 6 ASSEMBLY 8 INSTALLATION 9 DIGITAL NOISE 12 ILER DDS WIRING 13 SCHEMATICS 13 PART TWO PROGRAMMING AND USING THE VFO DDS 15 FACTORY CONFIGURATION 15 USING THE ILER DDS 15 USER MENUS 16 MENU FLOWCHART 17 CONFIGURATION 18 ANNEXES 22 IF YOUR KIT DOES NOT WORK AFTER FINAL ASSEMBLY 24 LIMITED WARRANTY 25 OUTPUT SIGNAL IMAGES 26 ...

Page 3: ...to 10 MHz Programmable IF Offset IF RF VFO IF RF VFO IF VFO RF IF 0 RF generator Programmable upper and lower band limit Fine calibration of the frequency reference by software up to 1 Hz accuracy Voltmeter display with 0 1 V accuracy 0 01 V calibration Auxiliary I O pins for expansion 2 x SINUSOIDAL WAVE OUTPUT 2 x SQUARE WAVE OUTPUT LOW SPURIOUS TX and RX mixers spectrum is equal to or better th...

Page 4: ...roperly solder you must use the correct type of iron and the right quality of solder Use a small tipped soldering iron whose bit is short and pointed at the end The iron should be about 25 30 W if it is not thermostatically controlled Only use multicored solder for electronics NEVER use any extra flux You should hold the hot iron in contact with both the board and the part lead for about two secon...

Page 5: ...rds the notch on the socket or U on the outline Electrolytic capacitors These must be installed with the correct polarity The positive lead is always the long lead The negative lead is marked by a stripe on the body of the capacitor can Make sure the plus end of the cap goes toward the hole labeled with the Transistors and diodes The transistors have the silhouette printed on the board The diodes ...

Page 6: ...n encoder terminals 100n 100n 104 or 0 1 On encoder terminals Semiconductors Crystal Inductor Encoder Modules Checked Ref Value Ident Comment Circuit section IC1 7805 7805 5V regulator Regulator IC2 18F2525 I SP Microcontroller Controller IC3 MCP1825S33 MCP1825S33 3 3V regulator Regulator X1 20MHz 20MHz cristal uC clock L1 100uH SMD Factory soldered uC V Encoder Bourns Encoder PEC16 Rotary Encoder...

Page 7: ...nly need to be used according to the following table LCD Type R5 Backlight GREEN 0802A Ver1 0 10 Ω brown black black BLUE RT0802A 47 Ω yellow violet black BLUE LCM0802C V1 0 47 Ω yellow violet black You can vary slightly the R5 value R5 less increases backlight R5 can never be 0 Ω If you want the maximum level of backlight you can connect the pin 15 of the LCD directly to 5V but note that you can ...

Page 8: ...ady installed and there are no hard to install parts on the kit It is advisable that you inventory all parts to make sure everything is available and ready for assembly Each builder may have his her own way of organizing parts but if you do not you might try using a block of Styrofoam packing material Parts may be sorted by type and size ohms microfarads etc ...

Page 9: ...s two of 8 pin to be soldered to the LCD and two of 10 pin for AD9850 module In order not to be mistaken observe the photographs carefully 6 Voltage regulator Place the 7805 IC1 and MCP1825S IC3 with its lettering facing the board Place to IC1 the small heatsink included with the kit with the U facing outwards see the cover photo 7 IC2 Insert the PIC18F2525 I SP microcontroller into its socket 8 L...

Page 10: ...tremely simple and safe method and provides very good aesthetic results If necessary you can always remove the LCD and clean the glue residue Do not use hard to remove adhesives such as cyanoacrylate epoxy etc In the pictures below you can see a DDS block installation next to an ILER transceiver The DDS is attached with glue As the LCD is fixed to the panel the other two modules control board and ...

Page 11: ...nfigured to work this way Slick With its low power VXO it will be possible to operate on the field or up the summits with a small battery on your backpack And with the DDS and its backlighted LCD display a bit higher on consumption you will be able to operate on your car or at home It is simple Build your ILER complete including the VXO and adjust it as per the manual You will have to place the IL...

Page 12: ... from the display They may be recognized as they shift in frequency especially after a cold start up Should you perceive a background noise on your transceiver without any antenna connected and the noise changes when you touch or push the LCD this is an LCD noise Encoder noise and other switching digital noises The second very common source of internal noises on a receiver is the switching of inte...

Page 13: ...x shield It is not advisable to wire the LCD The LCD should be sandwiched with the control board By the way Do not forget to place two 100 nF capacitors directly between the encoder pins If need be you will have to make changes on the wire routing or the wire type it will be a trial and error procedure Sometimes low level noises detected may disappear when the antenna is connected and do not affec...

Page 14: ...2 1 VFO DDS Page 14 Please notice that none of the two models the common terminal is central It is to the right Solder two 100 nF capacitors directly to the encoder pins between active pins and ground SCHEMATICS ...

Page 15: ...placed at the input of the ADC conversor R2 and R3 S METER CAL Calibrated for ILER 40 S METER MODE Reversed VFO A B VFO A RIT ON OFF OFF CHANGE STEPS 1 kHz 100 Hz S METER or VOLTS Volts SET INI FREQS Current ones fixed frequencies are stored in VFO A and in VFO B LCD BACKLIGHT ON always lit LOCK Unlock USING THE ILER DDS It is very simple Once programmed its use is highly intuitive Dial tuning and...

Page 16: ...pect to the previous frequency Note If the TX signal of the transceiver is not connected to the DDS then the RIT will not act see the connection table and the Annex Connecting the RIT input CHANGE STEPS There are five fixed sequences of steps available for selection 1K 100H 20H 1K 100H 100H 20H 10K 1K 100H ALL STEPS Turn the encoder until CHANGE STEPS appears and make a quick push By turning the e...

Page 17: ... OFF LCD always off A quick push on the encoder will bring you back with the new backlight option to the frequency dial LOCK This function allows an easy and fast lock or unlock procedure for the dial when you are working on a fixed frequency Push the encoder for more than 1 second turn the encoder until LOCK appears on the screen and make a quick push LCD will turn off and the encoder will remain...

Page 18: ...per limit Make a quick push then you will have the option of entering any frequency in the range 0 to 40 MHz in 50 kHz steps This is usually the upper limit of the amateur band the receiver or transceiver is prepared for but it may be placed at whatever frequency you like even out of band Once the frequency is set make a quick push and the ILER DDS will start up normally YOUR CALL Keep turning the...

Page 19: ...gram you may use the EXIT entry These are the nominal IF configurations for the ILER 40 ILER 20 and ILER 17 transceivers BAND RF LOWER LIMIT UPPER LIMIT IF FREQ IF MODE VFO DDS OUT ILER 40 7 000 7 300 4 915 VFO IF RF 11 915 12 215 ILER 20 14 000 14 350 3 276 VFO RF IF 10 724 11 074 ILER 17 18 068 18 168 3 276 VFO RF IF 14 792 14 892 ILER 60 5 351 5 5 366 5 4 915 VFO IF RF 11 266 5 11266 5 Some con...

Page 20: ...ct tuning and your voice sound natural A third option similar to the previous one is to do the adjustment on the air while listening to a station of known frequency tweaking the calibration until you get a perfect tuning If you are using the ILER DDS as RF generator Should you have access to a good frequency counter and you trust its calibration just read the frequency generated by the DDS and twe...

Page 21: ...s This allows adapting the S Meter of the ILER DDS to the CAG circuit of any receiver You must adapt the S meter measurements to the voltage levels of your receiver Choose the DIRECT S METER or REVERSED S METER screen press the button and the S 0 screen will appear on the screen and on the second line the voltage level in mV that is currently entering the terminal 10 RA5 AN4 of the ILER DDS To sav...

Page 22: ...at the input of the ILER DDS must not exceed 4 9V In low HF bands levels S 0 S 1 S2 or even more are usually a noise signal you can save them with the background level of the antenna when there is no signal Keep in mind that in urban or industrial environments the background noise may represent a level of S 4 or higher It is not necessary to save all the levels in a single session The levels can b...

Page 23: ...ou can use as a reference for the ILER DDS S Meter and adapt it if necessary Remember that in no case can it exceed 4 9V Normally the receiver s AGC voltage is used This can be directly or indirectly proportional to the reception signal Choose the corresponding calibration mode in the CAL S METER menu DIRECT S METER or REVERSED S METER You can also experiment by building a small adapter circuit th...

Page 24: ...plied parts is very rare Prior to taking any measurements at the board have a good look check all connections inspect the board for parts not soldered solder bridges between tracks sockets with bad contacts or wrongly placed parts If the kit does not work as expected follow these steps in this order Check every step of the assembly manual the soldering work and the installed parts If you have acce...

Page 25: ...ntioned it will work according to its specifications It is your duty to follow the advices and recommendations of this manual correctly identify the parts use good working procedures and have access and correctly use the tools and instruments requirede for the assembly and adjustment of the kit In case you think any part for the kit is missing please make an inventory of all parts with the parts l...

Page 26: ...VFO DDS Page 26 OUTPUT SIGNAL IMAGES 10 MHz output signal Perfect sinusoidal form 10 MHz output signal Harmonics hardly appear 20 MHz output signal Second harmonic better than 50dBc the third harmonic does not appear ...