• FORUM
  • LOGIN
  • ADVERTISE

DDS VFO with AD9850 / AD9851 and PIC16F877A

Discuss and share your experience on homebrewing

DDS VFO with AD9850 / AD9851 and PIC16F877A

Postby vu3wij » Sun Mar 04, 2007 11:04 pm

Hi
I Have successfully completed a DDS with the following facilities. It uses Mcrocontroller PIC16F877A and AD 9850/9851 DDS chip. The main facility in this DDS VFO is any settings including chip type and DDS clock can be changed even after programming the Microcontroller CHIP.

1) DUAL VFO, that is VFO A, VFO B and A=B facilities.

2) UP to 50 RX frequency storage on MEMORY.

3) The Software allows 2 modes of operation,

a) VFO MODE, where the encoder is used to adjust the frequency.

While in this mode, VFO A or B is displayed on the top line of the LCD.

b) MEMORY MODE, where the encoder is used to select a previously saved frequency. While in this mode, MEM is displayed on the top line of the LCD.

4) KEYPAD Frequency entry and additional 7 Press buttons for other functions.

The remaining Functions included in the KEYPAD itself.

5) UP/DOWN fast search in three different steps using KEYPAD which is user selective.

6) SCAN and quick UP/DOWN search in three different steps with auto Repeat on PTT.

7) Frequencies are entered in MHz, the * is used to enter a decimal point,

and the # is used to ENTER the completed frequency.

If the first digit entered is the #, the number entered will be negative.

8) S- Meter reading from S0 to S9+40db in logarithmic db range.

9) Variable rate tuning to use the cheep mechanical encoder.

10) Step size can be changed from 1Hz to MHz range.

11) RIT facility.

12) VFO copy to MEMORY and from MEMORY to any VFO (A/B) facility.

13) AM/LSB/USB/CW modes Operation with PIC pin outputs for switching.

14) Allows -Ve and +Ve IF OFFESTS. Offset frequency = any value from min RX frequency to Max 999MHz

15) 10 RX BANDPASS filter selection for RX coverage from 1.5MHz to 30MHz. Usefull to set up an All band RX.

16) BAND PASS filter switching selectivity 1Hz and 1ms switching speed, which allows cross band Operation.

17) CW OFFSET adds to TX Frequency when transmitting thus avoids modulated CW.

18) Save to MEMORY and Copy from MEMORY functions.

19) Scan VFO frequency and Scan MEMORY facility

20) Time out function for ignoring any wrong entry in system settings.

21) Auto repeat function for respective keys.

22) Display Multiplier Option to use with VHF rigs

23) Menu screen allows user to change any settings in the setup screen.

24) All settings can be changed in the SETUP screen at any time even when the DDS is in working mode including DDS chip type and Reference Clock.

25) LBS/USB/CW Crystal switching (USB is treated as CW).

26) CW OFFSET adds to TX Frequency when transmitting thus avoids modulated CW.

Image


Image

Image
{{photo by Dragan Jemelka}}

Image
{{photo by Dragan Jemelka}}

Image
This is the NEW VERSION of my DDS. It will support both 16x2 line as well as 20x4 line LCD.

The circuit and other details can be downloaded from the bottom attachement.

https://sites.google.com/site/pbshaji/ for more details.

Interested homebrewers may Email me for other details, PCB and programmed PIC and more info.

DDS PCB ( Double sided PTH, FR4 grade, SMOBC,HAL,BBT, size = 7.5cm*15cm ) + KEYPAD PCB + PIC16F877A programmed = Rs.600/- (15USD)
KEYPAD Pcb is 6.5cm*13cm glass epoxy.
Each PCB set carries all the circuits and operating instructions.

DDS Case is 17cm(W) * 7.5cm (H) * 14cm (B), MS, 1mm thick, powder coated with sticker.

I can send the PCB anywhere in the world using Registered INDIA POST.

ASM code or HEX file is not provided because of its misuse for commercial purposes.
So, please don't request it.


SHAJI.P.B VU3WIJ
KOZHIKODE, INDIA
Mobile: +91 9809 866 866 ; +91 9349 449 339
Email: pbshaji@gmail.com ; vu3wij@hamradio.in
URL : http://groups.yahoo.com/group/dds_vfo/
URL : https://sites.google.com/site/pbshaji/
Attachments
DDS_2012.zip
New Version
(233.31 KiB) Downloaded 1532 times
Last edited by vu3wij on Wed May 02, 2012 11:06 pm, edited 19 times in total.
vu3wij
 
Posts: 28
Joined: Wed Jun 18, 2003 12:00 am

Postby mvs sarma » Mon Mar 05, 2007 2:43 pm

Hi VU3WIJ,

Congratulations Shaji.P.B

Looks Pretty GOOD both PCB and the finished product.

A real hard work for the type of finish you Gave.

What are specifications like range coverage-- whether software could be shared - i request , if possible to publish schematic and othe data.

Regards

Sarma
Regards
Sarma
mvs sarma
 
Posts: 637
Joined: Wed Oct 11, 2006 4:57 pm
Location: Hyderabad, India

Postby vu3wij » Mon Mar 05, 2007 11:52 pm

Hi,
Circuit I will send to you by mail. This will help me make Modifications at any time and will help me to provide latest version of software. I will be giving the software FREE along with the PCB.

DDS PCB is Double sided PTH, SMOBC,HAL,BBT, size = 7.5cm*15cm
KEYPAD Pcb is 6.5cm*13cm glass epoxy.
DDS Case is 17cm(W) * 7.5cm (H) * 14cm (B), MS, 1mm thick, powder coated.
The Box and includes, cooling fan, DC input connector, BNC out, PTT line socket, Sticker etc etc
DDS range will be normaly 45% of system clock. So If you give 180MHz clock You will get 80MHz max.

Hope to see you again

73's

SHAJI.P.B VU3WIJ
KOZHIKODE
Email: shaji@hamradioindia.org
vu3wij
 
Posts: 28
Joined: Wed Jun 18, 2003 12:00 am

Postby vu3wjm » Thu Mar 15, 2007 10:32 pm

Congratulations!!

Excellent work SahJi. Would like more details and PCB cost etc. You can drop me a line : lkorahul@yahoo.com.

73

Rahul VU3WJM
vu3wjm
 
Posts: 52
Joined: Fri Sep 19, 2003 12:00 am
Location: Lucknow U.P.

Postby vu3wij » Thu Mar 15, 2007 11:21 pm

Hi Rahul,

I have sent the circuit to you by mail. And here is those details....

I will be giving the software FREE along with the PCB. or if you need only the Programmed PIC, You can send one PIC with return courier charge, and I will program it free of cost and will send it back.

DDS PCB ( Double sided PTH, FR4 grade, SMOBC,HAL,BBT, size = 7.5cm*15cm ) + KEYPAD PCB + PIC16F877A programmed = Rs.500/- (13$US). Charging Only the expense I spend for it!!!!
KEYPAD Pcb is 6.5cm*13cm glass epoxy.
Each PCB set carries all the circuits and operating instructions.

DDS Case is 17cm(W) * 7.5cm (H) * 14cm (B), MS, 1mm thick, powder coated.

Hope to see you again

73's

SHAJI.P.B VU3WIJ
KOZHIKODE
Mob: +91 9349 449 339 or +91 9388 339 449
Last edited by vu3wij on Fri May 04, 2007 5:55 pm, edited 2 times in total.
vu3wij
 
Posts: 28
Joined: Wed Jun 18, 2003 12:00 am

Postby vu3wjm » Fri Mar 16, 2007 12:33 pm

Hi! Shaji,

It seems the mail didnt reach. try sending to all 3 ids, I am very much interested in your design as I am making a TRX clone of Elecraft K2 but using a DDS this will be very helpful to me. Also do drop me your AC details so I can deposit the required ohms. Programming would be no problem just the HEX would be good enough.

TNX & 73

Rahul VU3WJM

IDs:

lkorahul@yahoo.com

vu3wjm@yahoo.com

lkorahul@gmail.com
vu3wjm
 
Posts: 52
Joined: Fri Sep 19, 2003 12:00 am
Location: Lucknow U.P.

Diagram

Postby sp7ewl » Fri Mar 16, 2007 6:50 pm

Could you swnd me a diagram and some more info?
zibi@sp7ewl.com
www.sp7ewl.com
sp7ewl
 
Posts: 1
Joined: Mon Aug 22, 2005 3:14 pm

Postby vu3wjm » Sat Mar 17, 2007 9:27 am

Hi!

Got all info now truly a great job.

73

Rahul VU3WJM
vu3wjm
 
Posts: 52
Joined: Fri Sep 19, 2003 12:00 am
Location: Lucknow U.P.

Where can I get the crystal oscillator?.......

Postby sinosh » Wed Mar 28, 2007 3:57 pm

Dear shaji.....
If you can post the address of the vendors who r supplying this crytal oscillator used in the circuit,Then it would be very useful to me and all others,Please write the average cost also...........

regards
sinosh vu3pkq

sinoshpk@gmail.com
sinosh
 
Posts: 18
Joined: Wed Mar 01, 2006 12:33 pm
Location: Chennai

Postby vu3wij » Wed Mar 28, 2007 11:44 pm

Dear Sinosh,

Thanks for the reply. You collect

CO (Standard crystal oscillator), 5V, 14pin DIP size. Freq. variation of 0.1PPM ok.
Don't collect TCXO, VXO, or any such item. A simple Standard oscilator is ok. "BHEL" (www.bel-india.com) or "FOX" (www.foxonline.com/) oscillators are available in market. Many other economical oscillators made by several companies also available in leading electronic shops.
Without giving any specification, and by simply saying "CRYSTAL OSCILLATOR", these we can buy from market. cost starts from say arround Rs.60/-. any one of the following frequency can be used.

66.66MHz (either AD9850 or AD9851)
100MHz (either AD9850 or AD9851)
32MHz (32*6 = 192Mhz, can be used with AD9851)
30MHz (30*6 = 180Mhz, can be used with AD9851)

CO, 5V, 14pin DIP size. Freq. variation of 0.1PPM ok. Hope you understood.

Hope to see you again

73's

SHAJI.P.B VU3WIJ
KOZHIKODE
Mob: 09349 449 339 or 09388 339 449
vu3wij
 
Posts: 28
Joined: Wed Jun 18, 2003 12:00 am

Thank u shaji

Postby sinosh » Thu Mar 29, 2007 3:19 pm

Thank u shaji for the information
Regards sinosh
sinosh
 
Posts: 18
Joined: Wed Mar 01, 2006 12:33 pm
Location: Chennai

Postby vu3vwr » Sun Apr 08, 2007 6:40 pm

how much did the full project cost???

thanks
ragav
Ever experienced the fun of building your own rigs and chasing that DX station with QRPp???
vu3vwr
 
Posts: 51
Joined: Thu May 05, 2005 8:18 pm
Location: Chennai

Postby vu3wij » Mon Apr 09, 2007 2:54 pm

hello,

If you can assemble this VFO, Approx cost without AD9851 is Rs.2000/-

SHAJI.P.B.
VU3WIJ
vu3wij
 
Posts: 28
Joined: Wed Jun 18, 2003 12:00 am

Postby vu3wij » Sat Sep 01, 2007 12:04 am

Hi,

Here is the link to circuit. Please copy and load to your brouser. I am getting a lot of mails for circuit.

http://rapidshare.com/files/428518177/D ... lsNpcb.zip

https://sites.google.com/site/pbshaji/


SHAJI.P.B VU3WIJ
KOZHIKODE, INDIA
Mobile: +91 9809 866 866 ; +91 9349 449 339
Email: pbshaji@gmail.com ; vu3wij@hamradio.in
URL : http://groups.yahoo.com/group/dds_vfo/
URL : https://sites.google.com/site/pbshaji/
Last edited by vu3wij on Sat Apr 23, 2011 3:49 pm, edited 2 times in total.
vu3wij
 
Posts: 28
Joined: Wed Jun 18, 2003 12:00 am

dds vfo

Postby iz1neo » Fri Apr 17, 2009 3:28 am

very good project and very good the simpaty of Shaji
the vfo work very well in conjunction with bitx20 version 3 and both ssb generator is very the first stone for multiband transceiver
many thanks Shaji from Gaetano Italy
iz1neo
 
Posts: 2
Joined: Sun Feb 08, 2009 10:09 pm

Next

Return to Homebrewing

Who is online

Users browsing this forum: No registered users and 0 guests