N3ZI DDS

Yellow RCA Jack Shown not included in 2019 Version
Encoder and switches can be easily remoted
Sold as a kit, but with the DDS Chip soldered to the PCB, no other surface mount components.

Simplified LCD wiring. LCD Can be mounted to DDS PCB or remote

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Order through Paypal Version Standard DDS Kit with BLUE/WHITE LCD $89.00 USD Standard DDS kit with YELLOW/GREEN LCD $89.99 USD Standard DDS Kit NO LCD $80.00 USD Vintage (30 Mem) w/ Blue 16x1 LCD $94.00 USD Your Callsign (required) Sold Out Sold as a kit. Only with the DDS Chip soldered to the PCB. All the other parts are through hole, and the buyer must assemble and solder those LCD Module fully assembled and tested.

Standard Version available with Blue or Yellow LCDs

Vintage Version, 30 Memories 30% Larger Characters

Key Differences between Standard and vintage versions

Feature	Standard Version	Vintage Version
Recommended Application	Homebrew QRP Radios, Xtal controlled radios, and pre SSB radios with wide range VFO.	Collins, Drake, Heathkit SSB radios from the 70's & 80's, with limited range VFO's and Xtal bank. Can be used to add WARC bands to these radios. Most applications require a separate buffer amp.
LCD	16 chars, 2 lines, many others supported.	16x1 Only. 1 line of 16 character LCDs, (14 characters used) no other LCDs supported.
RIT	500Hz default, Set in user setup, saved, but not tunable.	Tunable, resets to 0.0 on band change or power up.
A/B VFO	Yes	No
Memories	11	30
Set Up	Detailed	Easy English Menus
Calibration	Better than 0.1Hz	To 1Hz
Serial Port	Allows Tinkering.	None
Space on LCD for custom	12 Characters	none
Tuning Step	1,10,25,100,1000 + Auto speedup	1,10,100,1000 Hz + 50K for some setup.
Dial Speedup	Yes	No
PCB, Schematic and parts list are the same for both versions, only he LCD and micro are different. You can upgrade any DDS (Oct 2011 or later) to the Vintage radio version, by replacing the Micro and LCD

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Manual w/ Schematic, Standard Version
Manual w/ Schematic, Vintage Version

• Separate 14 pin Aux connector for the following
  • TTL Level Serial communications compatible with USB to TTL converter (Std version only).
  • All switch and encoder signals for simplified remoting of controls
  • Outputs for Reset, Power and ground
  • RIT and , A/B VFO (Std version only)
• Mechanically stackable with supplied LCD module
• No configuration jumpers needed
• Improved brown out tolerance with added supervisory reset chip
• Adjustable contrast control standard.
• Power on self test LED.
• 30 Memories in Vintage Version

1) 1Hz step size.  This was the most requested  improvement, and this chip has it.  Furthermore the LCD will display the frequency with 1 Hz resolution.  I'm going to set the step size to something higher than that, but those of you who demand precision will be able to change the default step size.  The LCD display will show 9 digits of frequency (a sign, 2 megahertz digits, 3  kilohertz digits, and 3 Hz digits.  

2) No (or very little) overclocking.  All these kits will be shipped with 80MHz clock modules.   This along with an improved output filter will allow operation up to 34MHz.

3) Fast RIT and FSK.  This chip has two frequency registers, and there is a direct connection to select between the two.  Switching is instantaneous and phase continuous, you can use it with CW QSK and even FSK (RTTY) is you want.  The push switch on the rotary encoder allows you to set the RIT offset, tuning speed, and calibration.

4) Vastly improved Encoder tuning.  The dial now operates much like an analog VFO dial.  I have an acceleration algorithm that works very nicely, so the push switch for speedup is no longer required.  New debounce and other changes make the action smooth like an optical encoder using an inexpensive mechanical encoder.  There is no lag for the LCD, and no queuing, no glitches,  and catch-up.

5) Phase continuous frequency changes.  The old chip had to be turned off then back on for a frequency change.  So there was a brief but noticeable glitch.  The new chip has phase continuous frequency changes meaning than the instant a new frequency is selected, the output waveform continues smoothly by sloping and the proper rate for the new frequency

• 1Hz user tuning steps
• User settable rate via tuning knob
• 0.3Hz internal step size.
  
• Glitch free, phase continuous tuning.
• Virtually indistinguishable from an analog VFO
• Very fast tuning updates
  
• 100x faster than my previous DDS
• User friendly auto acceleration, with user adjustable parameters.
• Advanced debounce and tuning algorithms make the supplied mechanical encoder feel like optical encoder.
• User tweekable parameters to accommodate other encoders
• Very fast RIT frequency shift
• Better than 1us frequency shift time
  
• Can be used for QSK or FSK/RTTY
• Shift amount settable via tuning dial.
  
• Complete DDS kit
• Just plug it in, turn the dial, and outcomes your VFO signal.
• No computer needed. No Frequency counter required.
• A digital display is part of the DDS FULL Kit, and gives you full frequency readout
• Full precision LCD frequency readout to 1Hz resolution
• Serial LCD also sold with the kit
• Also Works with 3rd party LCDs including backlit LCDs More info
• 80MHz reference included
• Fast easy to use, user calibration, push then knob then zero beat to a reference
• Digital calibration in extremely fine 1ppb steps. (ppb=parts per billion)
• Maximum output frequency of 34MHz
• Microprocessor does not limit upper frequency
• Frequencies up to 39MHz will work, but with increased mirror spur
• DDS SPECIFICATIONS
• Total Harmonic Distortion: -66db dBcf
• Mirror Spur suppression -60 db to 30MHz, -45 db to 34MHz.
• Spurious-Free Dynamic Range (SFDR)
• Wide Band (0 to Nyquist) -60 dBc
• Narrow Band (±200 kHz) -74 dBc
• Performance details
• Main output is a filtered sine wave
• 250mV p-p, when driving 1K load.
• Secondary unfiltered analog output
• Info on Buffer Amp
• Supports IF+VFO, IF-VFO, and VFO-IF radios.
• Expands the frequency coverage of many radios.
• Only 1 surface mount part, 20 Pin TSSOP (AD9834)
• Solder it yourself, it's easier than you think.
• Kitbuilders will do it for $10
• Requires 9 to 15 volt DC supply, approx. 50mA, more if a backlit display is used.
• 10 Memories plus A/B VFO all with their own IF offset setting.
• Separate A/B VFO input signal line.
• Separate RIT memory & control
• IF offsets settable via RS-232 or LCD/Button/Dial
• Easy to set RIT from tuing knob
• Normal range +/-9.999KHz (1Hz steps)
• But can be set up +/-9.999MHz for special applications
• Non volatile memory storage of last operating frequency and all memories/IF's
• Front Panel components can be remoted (LCD, Rotary Encoder, Buttons)
• Top quality commercial PCB with Separate Analog and Digital ground planes for best output purity.
• TTL Level RS-232 serial port available for setup and debug Interface Manual
• Not required for operation
• USB possible using inexpensive 3rd party adaptor.
  (I have tested several adaptors off of ebay, with both windows and Linux, and they all work fine)