ZL1CVD DDS VFO = affordable accuracy, stability and the latest technology!

This DDS VFO module is ready to use and makes an ideal external VFO project for older HF transceivers. It is compact, very stable, easy to set up and use.

Ideal as an extremely stable internal VFO replacement for crystal locked or VFO transceivers - Codan, Barrett, Heathkit, Collins,  Drake, Etc.

Can also be fitted to CB's and other 10m/11m rigs as a replacement for crystals, crystal synthesizers & PLL's. Ideal for this purpose as the display can be set up to show the exact frequency.

Of coarse, it can also use it as a frequency generator or reference!

Even supports RIT (Receive Incremental Tuning) allowing you to work DX stations receive on slightly different frequency than they receive. Simply add a button and PTT input.

Also support an IF offset.

You don't need to be a programmer to make changes to the various settings - just a matter of pressing button and turning the encoder - changes are stored in permanent memory. 

Very easy to use as an external VFO alternative for:

• Yaesu: FT-101, FT-102, FT-107, FT-301, FT-901, FT-902, Ftdx400, Ftdx500, Etc

• Kenwood: TS-120, TS-130, TS-180, TS-520, TS-530, TS-820, TS-830, TS-900

A highly accurate and stable replacement for:

• Yaesu: FV-101, FV-102, FV-107, FV-301, FV-401, FV-901

• Kenwood: VFO-120, VFO-180, VFO-230, VFO-240, VFO-520, VFO-820, VFO-900

What you need to do:

1. Mount the DDS VFO into a suitable case

2. Connect the DDS VFO RF output to your transceivers external VFO jack

3. Connect 12V to 13.8V power – usually also available from the external VFO jack

4. Power up the DDS, press and hold the CAL button an enter the provided parameters for your transceiver.

Example: Programing the DDS VFO for the Yaesu FT-101 Series
The optional external VFO for the very popular Yaesu FT-101 series was the FV-101. It had an analogue display from 0-500KHz. The actual output frequency is 8.7MHz to 9.2MHz. This is easy to program into the zl1cvd DDS VFO as follows:

• Press and hold the cal button (soldered on the back of the encoder) for a few seconds until the DDS enters CAL mode

• Set Min Rx DDS Freq to 8.700000

• Set Max RX DDS Freq to 9.200000

• Set RIT offset to whatever you want, its default is 500Hz

• Leave TX offset at 0.000000MHz

• Set IF Offset to -8.700000

• Leave Multiplier at 01

Now the DDS will only display from 0.000000 to 0.500000. The actual output will be 8.7MHz to 9.2MHz.

• Power the DDS from pin 5 of the FT-101 External VFO jack - this is 12V

• Connect DDS output to pin 6 of the FT-101 External VFO jack - this is RF input

• Connect ground to pin 1 and pin 8 of the FT-101 External VFO jack

This new model is even more flexible as you can now set the output level to either 500mV or 1300mV by simply changing a jumper.

Looking for other DDS options?

I also sell just the bare PCB or PCB + microcontroller for those hams who want to build their own. All parts are through-hole types & the PCB is not too crammed - oldies with a magnifying glass (like me) can have a go! See my other eBay listing or ask a question.

You get it all!

When you buy my products, you get everything – firmware, source code, instructions and a very big thank you!

Instructions with circuit and layout details can be found here: ZL1CVD DDS DATA

Customer feedback:

Specifications

• Operating Voltage: 12.0V~13.8V high power, 7.0V to 16V low power

• Operating Current: 125mA+ depending on frequency & output level

• Output Impedance: 50 Ohms

• Output Level : 500mV (low power), 1300mV (high power).

• Frequency Range: 0.5MHz to 40MHz

• Output Stability: Determined by the Chinese DDS module but typically less than +/-5Hz after 1/2 hour warn up.

• Frequency Step: Continuously user adjustable in decades from 1Hz to 10MHz.

• Support 3.3v & 5V DDS Modules: Yes

• Source code provided: Yes

• In Circuit Serial Programming (ICSP): Yes (firmware can be upgraded without removing chip)

• Tuning Speed: Fast, smooth super fine tuning

• Encoder Delay: Not perceivable – turn encoder, display & frequency changes

• Receive Incremental Tuning: Yes (with user defined limits)

• Commercial Grade FR4 PCB: Yes with plated through holes and silk-screen

• Customizable Configuration: Yes, you can change all setting by pressing the CAL button. Setting are saved when you have finished.

• Dimensions (W x H): Controller board only 55mm x 36mm. Controller mounted on display 80mm x 36mm

Terms Of Sale

• This sale is for 1x fully assembled & tested DDS VFO. This includes controller PCB and all its parts, 16x2 LCD with mounting hardware, AD9850 DDS module & rotary encoder on wire with CAL button as pictured.

• Will only ship when payment has been received in full including shipping charges.

• Only payment method accept is PayPal. If payment has not cleared within 4 days of auction closing, eBay will be informed the sale has not been completed & the goods will be re-listed.

Shipping & Customs

• Standard shipping is via NZ Post (air mail) is NOT TRACKED, not insured, no signature required service that takes from 20 to 30 working days.

• Expedited shipping is via EMS (or equivalent) is TRACKED, insured, signature required service which takes 10-15 working days.
• Customs export declaration will be filled out as “Amateur Radio Parts” to the value of the final sale price. It is up to you to deal with any charges from your customs office or any other import duties, sales tax, VAT, etc.