Contact Me

Richard Visokey – AD7C
Email: ad7c @ arrl . net

63 thoughts on “Contact Me

  1. Hi Rich.

    I have been playing around with an arduino controlled AD9850 vfo and was looking for other sketches that would load directly into the Arduino sketch program so I could change the code and play with it.

    I downloaded your sketch but it won’t open. it requires another program to open. I am not a computer guy so I don’t know how to fix this. could you please help me out? I would like to be able to put it directly into the Arduino sketch program.

    Your vfo project looks like a good one and I would like to build it.

    Thank’s for your help.

    Paul. WA7SDI

    • Paul, just to be clear. I hope you realize that after you download my file you have to uncompress it. The .ZIP file is not an Arduino file but a collection of files. The arduino sketch file is inside the .zip.
      Also, your email address posted here came back as invalid…so please update if you want me to direct email you.

      Rich
      AD7C

  2. Hi Rich
    have found some interesting information on your site! Maybe you can be interested to see some my hobby constructions… I like Arduino project (I have built a rotator controller around it, works fine), but I still prefer “old fashion” single chip controllers, coded in assembler… http://ok1dx.dyndns.org/designs.html
    73 Pavel OK1DX

  3. Hi,

    I’m playing around with the DDS VFO, using your code and a board from W5JH with a arduino Nano controller.

    When I hook up a higher resolution rotary encoder I get flashing of the LCD when I spin the knob. I’m wondering about updating the LCD on some kind of timer schedule instead of with every frequency change. I haven’t tried it yet. I wonder if maybe a timer interrupt ever few milliseconds to check LCD update would avoid the flashing, just skip all of those updates that I wouldn’t be seeing anyway.

    Have you heard of this idea or maybe tried it?

    • Haven’t run into a ‘flashing issue’. A couple of encoders I tried have some very high res but I am unable to reproduce a flicker. Strange?

      … and the LCD only updates when the frequency changes. No change = no update routine.

      Rich
      AD7C

  4. Hi Rich,
    I’m doing a signal generator project using a AD9850 DDS, Arduino UNO board and a Arduino Shield LCD keypad for my electronics course and I’ve been playing with your AD9850 DDS VFO project.

    The problems I have been having are errors with the code i.e. “../Sig.c:574:9: error: request for member ‘OUTCLR’ in something not a structure or union” and the DDS pin name definitions being undeclared.

    Have you any ideas as to how i can remove these problems? Once I have the fault I am looking to adapt the program to suit the 6 buttons on the sheild LCD or possibly a keypad. Do you have any suggestions for these changes?

    Cheers.

    PS. I am an amateur programmer at best

    • Andrew, Sorry. I can’t be of much assistance. I have never used the LCD Keypad shield so I have no idea of the pin-out or how they work. I suggest starting with my schematic and comparing that to the shield schematic for the LCD and button connection. I believe you find the fault there. My sketch is NOT compatible with the shield. You’ll have to re-write my sketch to work with the shields different pin-out.

      Good luck.

      Rich
      AD7C

  5. hi richard ,
    I bought all the parts from ebay for your dds vfo design but I only bought a arduino chinese clone uno not the original arduino uno .
    I have connected it all up as per your circuit diagram .
    I did have trouble with the rotary library and then got it imported .
    I do have it setup in arduino as the arduino uno board type and the correct com port .
    the system device manager tells me that it is a “usb serial ch340″ as this is the type of serial chip that has been used on my clones .
    I can compile and upload the sketch but the circuit does not work .
    nothing happens on the lcd display hd44780 .
    I then tried using the examples for
    blinking display works ok
    1. serial input which monitors digital pin2 as a input , turned on the serial monitor .
    I then turned the rotary encoder and could sometimes see the state changing from 1 to 0 as I turned it therefore this works correctly.
    2 the example for the Lcd display to show “hello world” . I setup the pins as per your code 12,13,4,5,6,7 (I think it was) and I could not get this one to work .

    I am powering the dds, display and encoder off the 5v power built into the arduino itself , is this ok ??

    therefore I am just wondering if you now if anyone has been successful in getting it to work with the arduino clone or do you have any more suggestions to help me get it going .
    It is such a great design and thanks for your efforts .

    thanks

    andrew
    vk3jcm

  6. Hello Richard!

    I have interested in your AD9850 DDS VFO Project. I need a Arduino sketch program to build an experimental VFO. I need low frequencies, around 30KHz to 100KHz. Could you provide more informations about that?
    Best regards,
    Marcio – PY3MLS

  7. Hello sir
    I intersted to your project dds . I have a question . Which type arduino do you uesd . In this pase you said arduino Uno but in document said nsno v3 .
    I want make your oroject snd I do not know which arduino use.
    Best regards , EP4HR , hamid .73

    • You did not correct add the rotary library to the Arduino. Try to save the project with another name and then check that you have imported the library for the rotary controller.
      Rich
      AD7C

  8. when I push rotary step frewuency changes but when I rotate rotary both step and frewuency change .
    I do not connect 5V to rotary .5V must be connect or not?

  9. Hi Rich , very nice work you did . I’m new on Arduino and like to use your VFO to build a 80/40 RTX .In the VFO is the displayed frequenci the base starting frequency – the IF. For my project I need the possibility to switch between 2 base starting freq and 2 IF . I like to do it with a H/L output.
    ex : H = 80m = BSF (3.5 MHz ) – IF (870 KHz ) = output 2.6 MHz
    L = 40m = BSF ( 7MHz) – IF (4.4MHz ) = output 2.6 MHz

    Could this be possible ?
    thanks for your work , 73 , Marco

    • Hi Richard , I have my VFO working now ( on 80 and 40 m ) with all the stuff I need . I used your code and after some learning I was able to adapt your code .

      Did you use your project also on a AD9851 ?

      73, Marco

  10. Great !
    I’m trying to run DSS with ad9850 frequencies from 1.ooHZ up to 300KHz.oo.
    Is it maybe possibleand how ? (two decimals are required)
    Could you help me please?
    Thank you very very much.
    Marino

  11. Hi Rich
    I retired due to bad health a couple of years ago and decided I’d have a go with the DDS VFO to keep my mind active
    Ive spent a couple of years and have expanded the Code significantly along with a front panel PCB. I have built 10 units which cost me about £45 each. This includes an output to the display showing the band edges which provides an output for switching band pass filters. There is also an input for a bar graph signal strength meter included on the VFO display. Also an RIT and band select switch.
    +/- IF offset can be achieved from the front pannel controls. I can only give a taste for what I have done. I gave you the credit for the initial software in the start up screens. If you send me your email address I can send you all the code , PCB layots along with pictures for the project. I am trying to recoup the cost of pcb and parts for the project and am willing to sell at cost + postage. I am advertising on UK ebay.
    Thanks again for all you have done, and I hope I can complement your good work

    73 Dave

  12. hi

    can not find the code for the 9850, only the rotary encoder

    am i truly as draft as I feel ?

    I have a small 9850 board from ebay , a Mega 256 and want to gnerte 75khz, should be simply

    But when I load the library and simple defines to get started i get

    rctrlsca1.ino:88:1: error: ‘dds’ does not name a type
    code as loaded from examples

    #include
    #define data_pin 12
    #define load_pin A5
    #define clock_pin A4
    #define clock_hz 120000000LL
    dds ddschip(DDS9850, data_pin, load_pin, clock_pin, clock_hz); // set my dds up with

    what do I do ?

  13. Hello Rich!!

    Thanks for posting this software and “how to”. I have all my parts wired and ready to go. When I compile the code I get a few errors

    “Arduino: 1.6.5 (Linux), Board: “Arduino/Genuino Micro”

    AD9850_LCD_ROTARY_WMENUS.ino: In function ‘void setup()’:
    AD9850_LCD_ROTARY_WMENUS:43: error: ‘PCIE2′ was not declared in this scope
    AD9850_LCD_ROTARY_WMENUS:44: error: ‘PCINT18′ was not declared in this scope
    AD9850_LCD_ROTARY_WMENUS:44: error: ‘PCINT19′ was not declared in this scope
    AD9850_LCD_ROTARY_WMENUS_IF.ino: At global scope:
    AD9850_LCD_ROTARY_WMENUS_IF:17: error: redefinition of ‘Rotary r’
    AD9850_LCD_ROTARY_WMENUS:17: error: ‘Rotary r’ previously declared here
    AD9850_LCD_ROTARY_WMENUS_IF:18: error: redefinition of ‘LiquidCrystal lcd’
    AD9850_LCD_ROTARY_WMENUS:18: error: ‘LiquidCrystal lcd’ previously declared here
    AD9850_LCD_ROTARY_WMENUS_IF:19: error: redefinition of ‘int_fast32_t rx’
    AD9850_LCD_ROTARY_WMENUS:19: error: ‘int_fast32_t rx’ previously defined here
    AD9850_LCD_ROTARY_WMENUS_IF:20: error: redefinition of ‘int_fast32_t rx2′
    AD9850_LCD_ROTARY_WMENUS:20: error: ‘int_fast32_t rx2′ previously defined here
    AD9850_LCD_ROTARY_WMENUS_IF:21: error: redefinition of ‘int_fast32_t increment’
    AD9850_LCD_ROTARY_WMENUS:21: error: ‘int_fast32_t increment’ previously defined here
    AD9850_LCD_ROTARY_WMENUS_IF:23: error: redefinition of ‘int buttonstate’
    AD9850_LCD_ROTARY_WMENUS:22: error: ‘int buttonstate’ previously defined here
    AD9850_LCD_ROTARY_WMENUS_IF:26: error: redefinition of ‘String hertz’
    AD9850_LCD_ROTARY_WMENUS:23: error: ‘String hertz’ previously declared here
    AD9850_LCD_ROTARY_WMENUS_IF:27: error: redefinition of ‘int hertzPosition’
    AD9850_LCD_ROTARY_WMENUS:24: error: ‘int hertzPosition’ previously defined here
    AD9850_LCD_ROTARY_WMENUS_IF:28: error: redefinition of ‘byte ones’
    AD9850_LCD_ROTARY_WMENUS:25: error: ‘byte ones’ previously declared here
    AD9850_LCD_ROTARY_WMENUS_IF:28: error: redefinition of ‘byte tens’
    AD9850_LCD_ROTARY_WMENUS:25: error: ‘byte tens’ previously declared here
    AD9850_LCD_ROTARY_WMENUS_IF:28: error: redefinition of ‘byte hundreds’
    AD9850_LCD_ROTARY_WMENUS:25: error: ‘byte hundreds’ previously declared here
    AD9850_LCD_ROTARY_WMENUS_IF:28: error: redefinition of ‘byte thousands’
    AD9850_LCD_ROTARY_WMENUS:25: error: ‘byte thousands’ previously declared here
    AD9850_LCD_ROTARY_WMENUS_IF:28: error: redefinition of ‘byte tenthousands’
    AD9850_LCD_ROTARY_WMENUS:25: error: ‘byte tenthousands’ previously declared here
    AD9850_LCD_ROTARY_WMENUS_IF:28: error: redefinition of ‘byte hundredthousands’
    AD9850_LCD_ROTARY_WMENUS:25: error: ‘byte hundredthousands’ previously declared here
    AD9850_LCD_ROTARY_WMENUS_IF:28: error: redefinition of ‘byte millions’
    AD9850_LCD_ROTARY_WMENUS:25: error: ‘byte millions’ previously declared here
    AD9850_LCD_ROTARY_WMENUS_IF:29: error: redefinition of ‘String freq’
    AD9850_LCD_ROTARY_WMENUS:26: error: ‘String freq’ previously declared here
    AD9850_LCD_ROTARY_WMENUS_IF:30: error: redefinition of ‘int_fast32_t timepassed’
    AD9850_LCD_ROTARY_WMENUS:27: error: ‘int_fast32_t timepassed’ previously declared here
    AD9850_LCD_ROTARY_WMENUS_IF:31: error: redefinition of ‘int memstatus’
    AD9850_LCD_ROTARY_WMENUS:28: error: ‘int memstatus’ previously defined here
    AD9850_LCD_ROTARY_WMENUS_IF:34: error: redefinition of ‘int ForceFreq’
    AD9850_LCD_ROTARY_WMENUS:34: error: ‘int ForceFreq’ previously defined here
    AD9850_LCD_ROTARY_WMENUS_IF.ino: In function ‘void setup()’:
    AD9850_LCD_ROTARY_WMENUS_IF:38: error: redefinition of ‘void setup()’
    AD9850_LCD_ROTARY_WMENUS:39: error: ‘void setup()’ previously defined here
    AD9850_LCD_ROTARY_WMENUS_IF:44: error: ‘PCIE2′ was not declared in this scope
    AD9850_LCD_ROTARY_WMENUS_IF:45: error: ‘PCINT18′ was not declared in this scope
    AD9850_LCD_ROTARY_WMENUS_IF:45: error: ‘PCINT19′ was not declared in this scope
    AD9850_LCD_ROTARY_WMENUS_IF.ino: In function ‘void loop()’:
    AD9850_LCD_ROTARY_WMENUS_IF:64: error: redefinition of ‘void loop()’
    AD9850_LCD_ROTARY_WMENUS:63: error: ‘void loop()’ previously defined here
    In file included from /home/User1/arduino-1.6.5-r5/hardware/arduino/avr/cores/arduino/Arduino.h:30:0,
    from /home/User1/Arduino/libraries/Rotary/rotary.h:8,
    from AD9850_LCD_ROTARY_WMENUS.ino:8:
    AD9850_LCD_ROTARY_WMENUS_IF.ino: In function ‘void PCINT2_vect()’:
    AD9850_LCD_ROTARY_WMENUS_IF:108: error: redefinition of ‘void PCINT2_vect()’
    AD9850_LCD_ROTARY_WMENUS:84: error: ‘void PCINT2_vect()’ previously defined here
    AD9850_LCD_ROTARY_WMENUS_IF.ino: In function ‘void sendFrequency(double)’:
    AD9850_LCD_ROTARY_WMENUS_IF:119: error: redefinition of ‘void sendFrequency(double)’
    AD9850_LCD_ROTARY_WMENUS:97: error: ‘void sendFrequency(double)’ previously defined here
    AD9850_LCD_ROTARY_WMENUS_IF.ino: In function ‘void tfr_byte(byte)’:
    AD9850_LCD_ROTARY_WMENUS_IF:129: error: redefinition of ‘void tfr_byte(byte)’
    AD9850_LCD_ROTARY_WMENUS:106: error: ‘void tfr_byte(byte)’ previously defined here
    AD9850_LCD_ROTARY_WMENUS_IF.ino: In function ‘void setincrement()’:
    AD9850_LCD_ROTARY_WMENUS_IF:137: error: redefinition of ‘void setincrement()’
    AD9850_LCD_ROTARY_WMENUS:114: error: ‘void setincrement()’ previously defined here
    AD9850_LCD_ROTARY_WMENUS_IF.ino: In function ‘void showFreq()’:
    AD9850_LCD_ROTARY_WMENUS_IF:155: error: redefinition of ‘void showFreq()’
    AD9850_LCD_ROTARY_WMENUS:132: error: ‘void showFreq()’ previously defined here
    AD9850_LCD_ROTARY_WMENUS_IF.ino: In function ‘void storeMEM()’:
    AD9850_LCD_ROTARY_WMENUS_IF:181: error: redefinition of ‘void storeMEM()’
    AD9850_LCD_ROTARY_WMENUS:158: error: ‘void storeMEM()’ previously defined here
    Multiple libraries were found for “rotary.h”
    Used: /home/User1/Arduino/libraries/Rotary
    Not used: /home/User1/arduino-1.6.5-r5/libraries/Rotary
    ‘PCIE2′ was not declared in this scope

    This report would have more information with
    “Show verbose output during compilation”
    enabled in File > Preferences.”

    Would you be so kind as to give me a hand ironing out those problems?

    Thanks

    73′s

    KI6NRN

    • If you do not use an Arduino Uno you have to change the interrupts. It appears you are using a micro. Look through other posts on this board and find what others have done to make the Micro work with my sketch.

      Rich
      AD7C

      • Dear friends, I am using Arduino Nano V3.0 and got same issue (error: redefinition of ‘Rotary r’). I didnt find in discussion board how to change interrupts. Ive tried many combinations without success (Rotary r = Rotary(x,y). Can you help me please? Thank you very much. 73 de Felipe PY1IA.

        • The error you are getting is because you didn’t correctly include the Rotary library files. Fix that 1st.

          Then… you can review an older post from this board that contains the info about the NANO.

          admin
          on September 30, 2014 at 9:11 am said: Edit
          I don’t have a full sketch but I can tell you the main item you need to adjust is the interrupt. The Nano uses different interrupt pin assignments.
          Your problem is here:
          PCICR |= (1 << PCIE2);
          PCMSK2 |= (1 << PCINT18) | (1 << PCINT19);

          I think you move it to 8 and 9 if I remember correctly.
          Rich
          AD7C

  14. Hallo Rich,

    I try to compile your arduino dds schets.
    I still get a message : Exit status one.
    Wrong compile.
    What do I wrong???
    Libraries are present ( rotary lcd and eprom)
    Gr. Adriaan

  15. I found that when you get the Exit Status 1 error that if you use the earlier Arduino program 1.0.6 the code will compile and load into the Uno or Nano. Using the latest version of the program 6.X.X will result in the error.

  16. Rich,
    I was wondering if you ever built a Superhet you once asked me about. I felt bad I didn’t document the schematic. Well, I’ve since built another receiver. This one uses 3 cheap ceramic resonators as the IF filter, an IF IC, etc. The best thing about this unit is a variable AGC. The NE602 is notorious for swamping out with strong signals. This unit uses an op amp off the volume level (slowed down by a cap) amplified and connected to the in input signal of the NE602 which dampens things. Due to the 2 year process of ripping it apart and rebuilding it a thousand times, no schematic for this one either. But the heart of the circuit is your VFO. I wish I could do better with the front end so that I don’t get those reflection/spurious signals.

    Harold Lacadie

  17. Hi OM:
    I am putting together DuWaynes SNAjr II and was trying to find the your rotary encoder file since this library needed to compile the the sketch. Any help is appreciated thanks. K7RSB Ross Bell

  18. Hello Richard ,
    I’am Nelu YO9BXE and live in Targoviste ROMANIA.
    Your project Arduino DDS VFO-IF is very interesting and it works very well. There’s a small delay from the rotation frequency encode to display but no bother.
    I would like to implement a +/- RIT 10kHz. Can you help me? I do not know how to do this alone. If you have an email address I can send multiple images and movies about this project. My email address is yo9bxe@gmail.com

    Thank for your amability. Best regards , Nelu

  19. Hi Richard,

    I have been working on a DDS 9951 project and ran upon something interesting and would like to ask your opinion please. The DDS 9951 software I wrote works fine except for one thing. I find that the RESET logic does not affect the DDS. Shouldn’t taking the logic level LOW-HIGH-LOW-HIGH cover any possible RESET logic requirement? I’ve tried grounding the pin; I’ve tried giving it pulses of H/L L/H and of course all the 3-pulse combinations. Would your opinion be that it must be hardware since I did not build the module and have no way to verify the RESET circuitry. It just seems that RESET does nothing. To get a RESET (and subsequent output), I have to “jockey” the power supply connection while sending it the software-generated setup and tuning words. Once and a while, I will hit it and the DDS starts. Once started, no manner of RESET logic will stop the DDS (reset it). Strange or what? Thank you sir.

  20. Hello Dear Sir
    I made your DDS project as RF signal generator and it work very well . I want use DDS Arduino for a Ham TRX radio and I need more PIN so I use Arduino Mega 2560 but rotary doesn’t work .I know problem is on interrupt but I can solve problem .can you send a rotary code for Arduino mega 2560 .
    Best regards ,Hamid EP4HR

  21. Sorry Rich because before I see other comment I ask you for Mega2560 .
    Nikki answer this question and I change code according Nikki comment and now I work DDS VFO
    By Mega 2560 .
    Nikki comment is here :
    On the Mega2560 use the attachInterrupt() function in the setup() part of the program. The lines that reference PCICR , PCIE2, PCMSK2, PCINT18 and PCINT19 as well as the sei(() function in setup() can be commented out or deleted. This amounts to 3 lines towards the top of the setup() function. The new code uses attachInterrupt() for INT_0 & INT_1 like this:
    attachInterrupt(0,MyIsr,CHANGE);
    attachInterrupt(1,MyIsr,CHANGE);

    Next you simply want to change the name of the ISR service routine (called ISR) from ISR(PCINT2_vect) to void MyIsr(void).
    Best regards Hamid ,EP4HR

  22. Hi, my DDS 9850 works well, however the output freq is a little to high.
    Must I increase ore decrease the 125 MHz clock on 9850 in the Arduino code to get the output right ??
    Tnx in advance

    Greetings KeesJan

  23. Hello
    I made your DDS project running a xtal controlled transmitterr and it work very well.
    However the DDS output freq is a little to high.
    Do I have to change the 125MHZ freq or the other number up or down to adjust the DDS freq.

    int32_t freq = frequency * 4294967295/125000000; // note 125 MHz clock on 9850

    Please let me know
    Tnx in advance / Greetings KeesJan – Pe1PIC

    • Change “4294967295″ slightly higher or lower to help calibrate the output of your DDS. Be sure to let your DDS run and warm up for at least 20-30 minutes before calibration.

      Rich
      AD7C

  24. Hello I am using Arduino genuino/uno.
    I tried to load program many times but fail. one times goes good and working fine.
    Now I have tried again to load program ad return the following error.
    Arduino Ide version 1.8.0
    Error is the following:
    Arduino:1.8.0 (Windows 7), Scheda:”Arduino/Genuino Uno”

    exit status 1
    redefinition of ‘Rotary r’

    Questo report potrebbe essere più ricco di informazioni abilitando l’opzione
    “Mostra un output dettagliato durante la compilazione”
    in “File -> Impostazioni”

    Can you help me please
    many thanks

    regards

    Salvatore

    • You did not load the rotary library. You must import the rotary library into the sketch and then it will compile correctly.

      Rich
      AD7C

  25. Hi Rich,

    I am planning to build a version of your DDS VFO for an old TS-820S. Have you or anyone else been able to add RIT to the VFO? I’m primary a CW op so RIT is important for me.

    73 Bill NZ0T

    • RIT is completely possible but I don’t know of anyone who has implemented it. It shouldn’t be that hard. You can just use the IF version of my code and rather than have a large IF offset you can have just 1 or 2khz adjustable offset.
      Rich
      AD7C

  26. Rich, I’m trying to add the capability to control RIT via an analog voltage. I’d like to vary the output frequency + and – 1000Hz when the voltage on the analog pin going from 0 to +5V. I’m a novice with the Arduino. I’ve been told that I need to map the voltage on the pin using something like this:

    int rit = map(analogRead(PIN), 0, 1023, -1000, 1000);

    Any help is appreciated. Thanks. – Curt, K8AI

  27. Hi Rich,

    I checked your code for AD9851 (your updated version) on 328p. Any changes on the interruption routine?

    Regards,
    David

  28. Rich,
    I am SOOOO close to getting your DDS VFO up and running……
    My trouble is understanding the proper hookup of the rotary encoder.
    The encoder I have has 5 pins: GND, +, SW, DT, and CLK.
    Your schematic shows the encoder with 5 separate connections; 2 go to ground, and the remaining three connect to the Arduino, but, they are not labeled on the encoder side.
    Would you be willing to clarify those pin connections/labels on the encoder so I can hook it up properly? So far, the combinations I have tried are not working….
    So very much appreciated, Rich.
    Your DDS project has received much attention!! Great stuff!
    So excited to get this thing working……
    73
    Pete
    KD2OMV

  29. Hello Richard,
    Thanks for the great and very useful project. I am retired and 70 and been a builder for 55 years. Been Using MElabs Picbasic Pro for a decade+ and have built some cool stuff, but the Arduino Family of boards have allowed me to build things that I could only dream of.. and Beyond. I have built the Projects in QST over the last years and found a need for a DDS Signal Generator as I stumbled onto your project. I had all the parts and wired it just like the Schematic and after a few minutes of troubleshooting I got it loaded and working. I had an Old HP step attenuator in 10db steps and put DDS rf into it and could feed my HF rig direct with a pretty low level clean signal. Something I needed. That’s why hams build stuff. Anyhow… Thanks again for empowering us old timers.
    WA2NAF

  30. Hi Richard ,
    Thank you very much for your free VFO sketch. I made , adapted changed and re-adapeted you VFO dozens times and I’m still wondering about it . No I made a new 6-band transceiver and I use again your VFO.
    Problem is : I do not understand the lines ( no knowless ) – ISR(PCINT2_vect){…..
    My question : how can I use this lines twice 1 x for increment of the step and another for increment of the bands ( 80 to 6 meter ). Ofcoarse I can use A0 to A5 but I need this ports for other use . How do I adapt this code ( just the ISR , not the upper or lower limit ) Can you help me on the way ? 73 Marco , F8VOA , France

  31. Hi, how are you? My name is Norman, I would like to ask you something about your “AD9850 DDS VFO” that you made long ago.

    Replify your circuit and work correctly. I only have a problem, that’s what I think, the AD9850 HC-SR08 module heats up quickly, but, I don’t know if the same thing happened to you. Add a heat sink but the problem persists, you have Any idea what that might be?

    • Check for the correct voltage. Also, if the unit is not a genuine manufacturer part it may be defective. A lot of fake AD9850 chips.
      -Rich

  32. I am very interested in your 31′ long whip antenna. Do you have a more detailed description of this antenna? Like what telescopic mast did you use? what wire did you use? Is this something that can be purchased? What hf bands is the antenna resonant? w/o tuner? I’d love to have something like that in my backyard.

    I have a 17′ tall MFJ-1979 telescopic multiband antenna with a loading coil for 80m and 40m but yours looks a lot more powerful!

    Thanks!

    Henry, KJ6KQW

    • I used a fiberglass telescopic “wind-sock” mast. The brand was JackKite. You can also use an MFJ 33′ version available at most all Ham Radio Outlet’s but it’s a little tall. I found that 31′ works best at least for me.

      With a minimum of 4 radials (north, south, east, west) of the same 31′ length and just the 31′ mast with a wire inside for the radial, the antenna can be brought to resonance on the 40M band. Mine tunes well at 7.150mhz. With an auto-tuner at the base (LDG), I am able to tune the top of 75M all the way through 10M with no issue. Works excellent on 20M, 17M, and 15M. I do not have a loading coal. Just the antenna, radials, tuner. Simple.

      Rich

  33. Hi Rich,

    I design and build my own 40 meter receivers to cover 7000 to 7070 kHz. I recently built a kit I got on eBay that is a superhet design from China. It has significant drift in the vfo. I built your Arduino Uno AD9850 vfo and it works well. I will use it to replace the vfo function in this drifting receiver. My question is when I first power up the AD9850 and the Arduino Uno I have to connect pin A5 to ground through the 1K resistor and leave it permanently to make it work. Also, I have to press the switch on the KY-040 rotary encoder a few times to get the 7.150 10 HZ display. Once I get there I am able to dial in desired frequencies. This does not seem normal. Am I doing something wrong?

    Best regards,
    Willard
    WA4VSR

  34. Dear Sir I am trying to find out The ID or part number for the gold out put connector used on the0 to 55 mhz DDs made in China and sold on EBAY can you help? thank you for your time from Jerry KR4BR 73s.

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