Craig, AAØZZ - Radios and Workbench                                               My ham station in 1966 (age 16)   -  Grand Rapids, MN

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Also see my personal (non-ham) home page at


AAØZZ Phasing Rig (In Progress)     2022-03-28

  Here's the current version of the 40M rig with 5 plug-in boards and a base board.  It will eventually have side, top and front panels.


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  Here's a rundown of the various plug-in boards.

   1) Signal Generator Schematic (JPG)

The Signal Generator has 2 PIC microprocessors.  The 28-pin 18F2520 controls the Si570 RF source, the LCD, and the rotary encoder.  The small 8-pin PIC (12F1822) has a stripped-down version of my EZKeyer to generate the DITs and DAHs for keying the CW transmitter.   This version has only one pushbutton to control the keyer's menu, change speed, and to send one canned message.   

The Signal Generator will be the "front" board so it also has the volume control for the receiver. 

The Signal Generator board has had 15 PCB revisions.  

NOTE: I wrote every line of code for the entire project in PIC assembler code. NO LIBRARIES!   

   2a) Phasing Receiver Schematic (Left Side) (JPG).   

   2b) Phasing Receiver Schematic (Right Side) (JPG)

The receiver uses a Quadrature Sampling Detector (QSD) front-end, an audio phasing section (for single-sided reception) which is a take-off from Rick Campbell's (KK7B) R2Pro, an audio bandpass filter, and then an audio amplifier.  

The Receiver board has had 35 PCB revisions !  I'm glad they are so inexpensive!

   3) 28W CW Transmitter Schematic (JPG)

This version of the transmitter is CW only but the front-end is Class AB so it will be used later for SSB/digital.  The final amplifier has two RD16HHF1 MOSFETs  in push-pull configuration and produces 28w.    

The transmitter board has had 22 PCB revisions.  

   4) High Power T/R Switch (JPG)

This T/R switch is an overkill for a 28w transmitter but it's done in preparation for higher power.  A simple PIC (12F1822) generates the 2 MHz pulses for the charge pump which develops 150 v (loaded) for back-biasing the PIN diodes.   This T/R switch can easily handle 100w.   

The T/R board has had 8 PCB revisions.  

  5) Filter Board Schematic (JPG)

Filter shows components for 40M and 20M but the current rig only runs 40M.  The 20M input bandpass filter will be changed to an Low Noise Amplifier (LNA).  

(Scroll down to see LPF)

   6) Board-to-board Connectors (JPG)

   7) Base board showing Connectors (JPG)

   8) Receiver board showing Connectors (JPG)

   9) Signal Generator board showing Connectors (JPG)


As of 3/28/2022 I have "frozen" this version since it works well enough to make contacts on 40M.  I'm having a ball, having many extended conversations with folks all around the US and also some short DX contacts into Europe. 

I'm now working on a 20M version with new set of plug-in boards on a new base board.   Moving to 20M entails modifying the software in the Signal Generator (easy peasy) and a new plug-in filter board.   This time the filter will be a LNA filter. 




40M Direct Conversion Transceiver

Dimensions: 4" x 2.5"


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MiniDC with no cover(JPG)

MiniDC with no case, LCD, knobs (JPG)

Signal Generator Schematic (JPG)

Receiver Schematic (JPG)

Transmitter Schematic (JPG)

"Boneyard" of forgotten MiniDC favorites(JPG)


AAØZZ Project Enclosures


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          4" wide, 2.5" deep, 0.75" high (BLACK)

          4.5" wide, 4" deep, 1.5" high (BLUE)

     5.5" wide, 5" deep, 2" high (RED)

            6.5" wide, 6" deep, 2" high (PURPLE)

Enclosure Assembly Manual (PDF)

Sorry, no longer available from Four States QRP Group


The AAØZZ ZZRX-40 Receiver

    A very simple 40 Meter receiver using very few parts    

    My QST Article - July 2016    

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ZZRX-40 Article (PDF format)



ZZRX-40 PCB                                                     ZZRX-40 PCB in Case                                                   ZZRX-40 Complete

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ZZRX-40 Assembly Manual (PDF format)

Schematic - ZZRX-40 Receiver (JPG format)

Theory Of Operation - Direct Conversion Receivers Including ZZRX-40 (PowerPoint .PPTX format)


Sorry, kits are no longer available



A Simple CW Keyer With Advanced Features    


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Kits are available from Four States QRP Group (


The AAØZZ Si570 Daughtercard and Control Board

    A Programmable PLL (Si570) VFO for Amateur Radio Applications    

    My QEX Article - July / August 2011    


(Click on picture to open article - in PDF format)

AA0ZZ Si570 PPLL-VFO Article (input to QEX) - (PDF format)



Daughtercard                    Control Board with Daughtercard                         Daughtercard in PIC-EL

Daughtercard User Manual (PDF format)

Daughtercard Schematic (JPG format)

Daughtercard Parts List (PDF format)

Control Board User Manual (PDF format)

Control Board Schematic (JPG format)

Control Board Parts List (PDF format)

Block Diagram - AA0ZZ Si570 in CW or SSB Receiver (JPG format)

Block Diagram - AA0ZZ Si570 in CW Transmitter (JPG format)

Block Diagram - AA0ZZ Si570 in SSB Transmitter (JPG format)

Schematic - AA0ZZ Si570 in CW Transmitter (JPG format)

Schematic - AA0ZZ Si570 and QSD using PC for audio (like SoftRock) (JPG format)

Schematic - AA0ZZ Si570 and QSD using KK7B MicroR2 LNA and Audio (JPG format)

PEgen570 v7.7A PIC Source Code (ASM format)

PEgen570 v7.7A PIC HEX code (Save as .TXT, Rename as .HEX)


Si570 User Pages

    W6JL - Don Huff (updated 8/4/2011)


Sorry, kits are no longer available.


See my YAHOO Group: PPLL-VFO  for Support / Discussion / Files / Pictures / Documentation



    PIC Microcontroller Programmer and Development Board    

   Now with a USB Interface!   


Feb 2010 QST

(Click on pictures to open)


See my YAHOO Group: PIC-EL  for Support / Discussion / Files / Pictures / Documentation


Elmer 160 Lessons by John McDonough, WB8RCR

    Learn about programming PICs using the PIC-EL Board    

   Lesson Download Page   

Microchip PICKit2 Application (for PIC-EL III)

    Use with Elmer 160 Lessons    

   Microchip PICKit2 App   


   IQPro and LNA/LPF kits

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            IQPro                                            LNA/LPF (for IQPro)                     


My Recent Articles

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       IQPro in May/June 2006 QEX magazine             



     PIC-EL in May and June 2007 QST magazines           


               Part-1                                           Part-2                        


Older Ham Radio Projects


A 0 - 30 MHz VFO Using an AD9854 Direct Digital Synthesizer

By Craig Johnson, AAØZZ

See my article about the IQPro in May/June 2006 QEX magazine above

What is a DDS VFO? Very briefly, in simple terms, a Variable Frequency Oscillator (VFO) is an electronic
mechanism that creates a sine wave at a desired frequency. This VFO is designed to be used as
a "tuner" for a radio transmitter or receiver. VFOs are often constructed using variable
capacitors or coils that are moved to change the frequency but this VFO uses a newer technology, a
very tiny Direct Digital Synthesis (DDS) chip, controlled by a small computer (microcontroller),
to create the sine wave at the desired frequency.

IQPro Features   (Updated 10/21/2005)

1) The IQPro is a 3" x 6" board, split into two halves. The "control" half contains the two PICs and headers for the pushbuttons, LCD, LEDs, and band-switching. The "RF" half contains the AD9854 DDS and the amplifiers. The intent is to allow the builder to put the RF portion into an "RF-tight" box. This split also opens up the possibility of driving the "RF board" directly from a PC (serial or parallel port) or from another control board.

2) The entire board runs on 5v (12v optional). Has a 3.3v regulator (no heat sink) for the AD9854.

3) No MMIC amplifiers. Instead it has three options for boosting the AD9854's I and Q outputs up to +7 dBm or higher. (Parts are supplied for all three options.)

Option 1: Toroids only. 12v power not needed. I and Q outputs of +7 dBm.

Option 2: Transistor amplifiers only. 12v power is needed. I and Q outputs of +7 dBm.

Option 3: Toroids AND transistor amplifiers. 12v power is needed. I and Q outputs of approximately +17 dBm.

4) No pushbuttons on the board (except a reset button). Instead it has a header to support a 24 pushbutton array (4 rows x 6 columns) which is ready for easy customization and movement to the front panel. The kit includes a PC board for mounting the pushbuttons but it is not required.

5) 12 pushbuttons (3 columns x 4 rows) form a telephone-like keypad for direct frequency entry.

6) 12 additional pushbuttons for UP/DN MHz, UP/DN Band, VFO-A/VFO-B Toggle, VFO-A = VFO-B, Fast-tuning toggle, Mode cycle (LSB, USB, CW-, CW+), Split toggle, Tone set, Backlight toggle, and Calibrate toggle.

7) No LEDs on the board. Instead there is a header to support 9 LEDs to be mounted on the front panel.

8) Nearly all through-hole parts. Exceptions are the AD9854, the 125-MHz clock, and one MOSFET for enabling the LCD backlight.

9) Two 16F877 PICs, an Interface PIC and a Driver PIC. The Interface PIC handles the encoder, the pushbuttons, the LEDs, and the band-switching. The Driver PIC handles the AD9854 and the LCD. The two PICs "communicate" with messages.

10) Output signals are sent to a header when the VFO frequency changes to a different frequency band. These signals can set/reset latching relays on an external board (not supplied) to engage band-specific receiver pre-amps or transmitter output filters (for harmonic suppression).

11) A mode-cycle pushbutton operates a latching relay which reverses the I and Q signals. If the mode is LSB or CW- the relay is latched in the "normal" position. If the mode is USB or CW+, the relay is latched in the "reverse" direction.

12) Sidetone. The frequency is shifted (plus or minus) by a selected amount when running in CW and Receive mode. The amount of offset (tone) is adjusted by pushing a pushbutton and then turning the encoder. The tone value is saved in EEPROM so it is not lost by power-down. The offset value is SUBTRACTED from the base (transmit) frequency if in CW- mode and ADDED to the base (transmit) frequency if in CW+ mode. This allows you to listen to CW signals on either sideband.

13) LCD (16 x 2) with backlight toggled on/off via pushbutton.

14) 12v to 5v switching power supply kit included (about 1" square"). It is meant to be mounted at some convenient location in the case.

15) The manual has MANY design details including the theory of operation, reasons for design decisions, block diagrams, SPICE modeling of the amplifier, schematic, and a complete parts list (almost all DigiKey part numbers).

16) FULL SOURCE CODE FOR THE TWO PICs IS SUPPLIED! This allows the builder to completely understand how it works and to modify the operation to suit individual preferences.

Kit Options:

Three options are being offered:

    1) Full kit - $CALL

    2) Bare board set (no parts - boards only) - $25 plus $2.50 s/h ($5 via Priority Mail)

    2) Pre-programmed PICs (pair) - $25 plus $2.50 s/h ($5 via Priority Mail)

Please note that full kit includes the PC boards, printed manual, parts for the boards including pre-programed PIC's, pre-mounted AD9854 chip, and a very high quality Clarostat optical (not mechanical) encoder.

Contact me. I still have all of the "key components" available. See details at the top of this web page.

Pictures, Block Diagrams and Schematics:

    IQPro running

    IQPro main board

    Block Diagram of IQPro

    Block Diagram of IQPro in Receiver

    Block Diagram of IQPro in CW Transmitter

    Block Diagram of IQPro in SSB Transmitter

    IQPro Schematic (page 1 of 2)

    IQPro Schematic (page 2 of 2)

    IQPro Operations Manual (PDF format)

    IQPro PIC microcode source code

Hint: Save the schematics on your hard drive and then open them with a picture viewer to see details.

Multi-band LNA/LPF Board for IQPro (NEW!)

    WHAT IS IT? Multi-band LNA-LPF Explained

    Multi-band LNA-LPF Schematic

    Multi-band LNA-LPF Board Picture

    Multi-band LNA-LPF Parts List (Excel Format)

IQPro Performance Reports / Measurements

    IQPro Phase Noise Measurements (Rev-1 8/5/2006) - by Gary Johnson, WB9JPS

    Wes Hayward, W7ZOI, comments regarding WB9JPS analysis of IQPro

IQ-VFO and IQPro User Pages

    WB9JPS - Gary Johnson (8/7/2006)

    W6JL - Don Huff (updated 8/16/2008)

    K5EMI - Bill Stewart (5/27/2007)

    KA8RIZ - Steve Geary (3/25/2007)

    KD5BYB - Ben Hall (2/24/2007)

    G3UGR - Clem Tabor (3/4/2007)

    AB7O - Wayne Thurston (6/12/2007)

    AA3SJ - Ed Kessler (link to Ed's page 3/24/2007)

    WB9JPS - Gary Johnson (link to Gary's page 11/12/2007)

    K8AC - Floyd Sense (link to Floyd's page 1/3/2008)

    W3PM - Gene Marcus (8/19/2008)

    DL1SE - Juergen Zink (9/4/2009)


See my YAHOO Group: DDS-VFO  for Support / Discussion / Files / Pictures / Documentation

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Start of "Retired" kits/projects


A 0-30 MHz VFO Using an AD9854 Direct Digital Synthesizer

Designed by Craig, AAØZZ and Bruce, AAØED

See my YAHOO Group: DDS-VFO  for Support / Discussion / Files / Pictures / Documentation

Complete Manual: Manual Ver 1.0f  (in PDF format)  Updated 01/31/05

Schematic: Page 1 of 2   (drawn with CircuitMaker)

                    Page 2 of 2

PIC16F877 Symbolics v5.19b     HEX    (Main Control)

PIC16F628 Symbolics v1.1c     HEX    (Encoder)

Parts List (updated 11/13/2004 - with prices)

Perfect quadrature output!   (0 - 30 MHz)

Performance Analysis  (PDF) New 01/31/05

Don Huff, W6JL, uses a HFVFO prototype with R2Pro

PowerPoint slides from my FDIM Presentation on May 15, 2003

Sorry, but the IQ-VFO kits are sold out and no longer available from AmQRP.

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HFVFO board - top

HFVFO board - bottom

HFVFO board - AD9854

HFVFO board - running

PIC-EL Version 2

(This is old - For reference only. See Version 3 info above.)

A PIC Prgramming/Demonstration board for the


By Craig Johnson, AAØZZ

See my article about the PIC-EL in May, June 2007 QST magazines above

(See details on how this project originated below)

   Download Page   

PIC-EL II Features:

  PIC Programmer for 18-pin PICs via PC Serial Port

  Test your PIC program with these hardware components:

        - 2x16 line LCD (with backlight)

        - Rotary encoder

        - Three general purpose pushbuttons

        - Three LEDs

        - Speaker with driver

        - Stereo jack for paddle input

        - Stereo jack with transistor driver to key a transmitter

        - Transistor conditioner for converting low-level signals for PIC input (counter) detection

  16F628 PIC - preprogrammed with PIC-EL diagnostics - included   (source code available)

  Use with PIC Programming lessons -

  Adapter kit for programming 40-pin PICs (16F877) also available.   (NOTE: The PIC in the adapter does NOT operate the PIC-EL hardware.)

Kit Options:

Full kit: $55     ($63 with ZIF socket)
Bare Board: $20

16F877 Programming Adapter Kit: $18
(Requires ZIF socket on PIC-EL board)

The PIC-EL II kits are no longer available.

Documentation and Schematic:

    Latest PIC-EL II Manual

    PIC-EL II schematic

    PIC-EL II - 16F628 Diagnostic - Source code

    PIC-EL II - 16F628 Diagnostic - Hex code

    PIC-EL II Flyer

    16F877 Adapter Instructions

    PIC-EL II Board vB4 Minor Rework Instructions

Hint: Save the schematic on your hard drive and then open it with a picture viewer to see details.

PIC-EL II Application Software (PIC 16F628)

    1) CW Keyer (K8-PE-V4) Source Code    HEX Code    Documentation

    2) DDS Signal Generator (PICELgen 6.0c) Source Code    HEX Code

    3) Frequency Counter (PECntr 2.7) Source Code    HEX Code    Calculations


See my YAHOO Group: PIC-EL  for Support / Discussion / Files / Pictures / Documentation

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See See: ELMER 160 Home Page

My contribution to the project -- to design the Programmer/Project board. (I called it the PIC-EL Board.)

Here's how it works!  PIC-EL Design Description


- My first conceptual schematic

- My first prototype (Manhattan style) - Getting the first bugs out. At least the programmer works.

- My second prototype - Now it's a signal generator (with my SIGGEN3+ code driving a DDS Daughtercard)

- 2-layer circuit board - The circuit board (created with WinBoard)

- Final Prototype - The final prototype


    - PICELgen v1.4 source code- Signal Generator using PIC-EL and DDS-30 DDS Daughtercard

    - PICELgen v5.2 source code- Signal Generator using PIC-EL and DDS-30/DDS-60 DDS Daughtercard

    - K8-PE-Ver2-Keyer source code- K8 Keyer (16F84) for PIC-EL  (Original by Steven Elliott, K1EL)

    - K8-PE-Ver2-Keyer documentation- Documentation for K8 Keyer (16F84) for PIC-EL

    - K8-PE-Ver4-Keyer source code- K8 Keyer (16F628) for PIC-EL  (Original by Steven Elliott, K1EL)

    - K8-PE-Ver4-Keyer documentation- Documentation for K8 Keyer (16F628) for PIC-EL

PIC-EL (Rev A) Modifications

    - PIC-EL 16F628 Mods - PIC-EL (Rev A) modifications required to use a 16F628 PIC

My presentation at ATLANTICON 2004 (March 27, 2004)

    - The PIC-EL and Beyond - My paper for the Atlanticon Proceedings

    - PowerPoint Slides - My presentation

The PIC-EL Version 1 kits were only available from AmQRP for a short time. (Approximately 800 were sold.)

The "latest version", called the PIC-EL III, is no longer available.

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PIC-EL Schematic

PIC-EL Production 1

2N2-40   (40 Meter transceiver - designed by Jim Kortge, K8IQY)

Design details at Jim Kortge's home page: K8IQY's 2N2 Homepage

Schematic   (drawn with CircuitMaker)

My 2N2-40 Layout   (PowerPoint format - to download and print - actual size)

My 2n2-40 transceiver

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Yes, it works!

SW-30+   (30 Meter transceiver - designed by Dave Benson, K1SWL)

Schematic in PDF format

My MH101 ("manhattan" style) version of the SW 30+    Picture 1   Picture 2

      - Pad layout in PowerPoint format (actual size): MH101 Pad Layout

      - All parts layout: All Parts

My MH101 transceiver

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Yes, it works too!

Biographical sketch (updated 5/2022): AAØZZ Bio

Send me E-Mail at:
(Sorry I had to show the Email address like this. I'm sure you know why.)

Go to my "main" home page at

Last Updated 10-May-2022
- Craig, AAØZZ

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