Projects:

Adding an I/Q output to the Elecraft KX2

A mini writeup of an ill-conceived little project, adding a homemade option board to the Elecraft KX2 transceiver.

Last upd: 2017-02-13

Status: New - added 2017-02-13

Power and SWR Meter - Rev II

An update to the original Power and SWR Meter project.

TFT Graphics and Touch display

or alternately, a 20x4 LCD, like previous project

Last upd: 2020-06-21

• Revision 1.03 of the TFT version. Maintenance update to accommodate changes in the ADC library.

• Revision 1.02 of the TFT version. Bugfix, ADC had a kink around 1.67V. Added power level floor settings up to 10 mW

• Revision 1.01 of the TFT version. A minor adjustment to keep it compatible with rev 1.36 of Teensyduino (updated ADC library)

• Detailed instructions added for compilation of source code. Also added some info and pictures describing a slightly improved version of the Tandem Match Coupler and AD8307 bridge.

• Revision 1.00 of the TFT version. Floor function added for the displayed power level, user settable at 1mW, 0.01mW, 1uW or no floor.

• Revision 0.99 of the TFT version. Bugfix of Reverse Calibration feature.

• Revision 0.98 of the TFT version. Added features

• Revision 0.98 of the LCD version. Encoder bugfix

• Revision 0.96 of the TFT version. Minor cleanup

• Revision 0.97 of the LCD version. Minor cleanup

• Revision 0.96 of the LCD version. Fixes a pin assignment discrepancy for the Enact switch.

• 2016-09-05 Firmware version 0.95 uploaded, some minor improvements.

• Project added 2016-06-12

Machine recognition of hand-sent morse code

Two easy to build microcontroller projects.

• • • • Take One, an Arduino Uno sketch

      • Take Two, Fast Fourier Transform and Colour Graphics

Last upd: 2016-03-20

To automatically tune a Magnetic Loop Antenna

• • • • Enter the Magnetic Loop Controller

      • Diagrams

      • Option: Automatic Tuning for best SWR

      • Firmware

      • Functionality and features

      • Configuration Menus

      • Operation of the Magnetic Loop Controller

      • Backlash compensation

      • Variable Capacitor Tuning Rate

      • Suggested first tests

      • Some notes about the LCD

      • USB commands

      • Youtube Video of the Controller

      • Epilog: To build a 24 foot Magnetic Loop

Last upd: 2020-06-21

• Firmware version 4.10.

  • Maintenance update to accommodate changes in HardwareSerial and ADC library.

• Firmware version 4.09.

  • Bugfix for DRV8825 / A4988 stepper motor driver option. Had glitches when switching between full and fractional step modes.

• New "BOM and Building Instructions" added for Rev3 / Rev4 printed circuit boards, which utilize the DRV8825 or A4988 Stepper Drivers

• Firmware version 4.08.

  • Update to stay compatible with latest version of Arduino/Teensyduino.

  • Added two transceivers, Yaesu FT920 and Kenwood TS870 (neither has been tested yet)

• Firmware version 4.05:

  • Added SWR Alarm output signal on pin/pad 33.

  • Backlash Compensation Select function changed to Backlash Compensation Adjust with an user (Menu) adjustable range of 0-400 steps

  • Bugfix: Some displays garbled when using the precompiled hex files with version 4.04

  • Bugfix: Endstop Option 2 had bugged logic around handling of upper endstop signal

• Firmware version 4.04:

  • Pushbutton function rewritten, now no false readings.

  • Kenwood TS2000 "TX;" issue addressed.

  • Improvement for endstop features 2 and 3.

  • Switch-in/switch-out capacitor feature improvement.

• Updated "Operation Instructions and Notes".

• Updated "BOM and Building Instructions" , adding a detailed description of the Dual Antenna Changeover feature.

• Firmware version 4.03. Main additions:

  • Pushbutton debounce improvement

  • Added USB commands for remote tune

  • Screensaver disable feature added

  • Further LCD handling improvements

  • USB commands made case insensitive and ';' added as USB command terminator.

• Firmware version 4.01 Improved handling of certain OLED displays.

• Firmware version 4.00. Main additions:

  • Triple Antenna change-over feature

  • Transceiver Profiles and tune power level management

  • Yaesu FT-1000 Mk-V, Kenwood TS-440/450

• Firmware version 3.07. Added Yaesu FT-990, minor bug fixes.

• Firmware version 3.06. Further Kenwood / Flex bug fixes.

• Firmware version 3.05. Kenwood / Flex bug fixes.

• Firmware version 3.04. ICOM bug fixes.

• Firmware version 3.03 - capability to handle 3 additional transceivers added

• Project added 2014-04-30

Power and SWR Meter with dual bargraphs, using 2x AD8307

microwatts to kilowatts, accurate SWR at 1mW.

Last upd: 2016-05-27

• • • • Some Display Examples

      • 10 bits or 12 bits ADC resolution

      • Microcontroller Firmware

      • Detector Circuit and Tandem Match Coupler

      • Circuit Description (Tandem Match and Detector)

      • The Controller Circuit

      • Meter Displays and Configuration Menus

      • Serial Output (USB virtual serial port)

      • Calibration Considerations

      • Some Measurement Data

(see also updated project: Power and SWR Meter - Rev II)

• A new version (rewrite) of the firmware, using the Arduino environment. Arduino sketch, v. 0.90.

• Firmware v.0.75, yet another bug fix. Thanks ON6ZG

• Firmware v.0.74, another bug fix, courtesy of M0KGV.

• Firmware v.0.73, bug fix.

• Firmware version 0.71, firmware bug cleanup.

• Firmware version 0.70:

• 12 bit ADC option added.

• Some tweaks of USB commands

• New and more stable USB-Serial stack

• Major rewrite of description.

• Project added 2013-09-29

Magnetic transmitting loop antenna excercises

Two magnetic transmitting loop antenna projects:

• • • • 0.5 x 0.5m loop using a manual stepper motor controller for tuning

      • 1 x 1m loop and an automatic microcontroller based stepper motor controller

Last upd: 2014-04-30

• Automatic Controller and firmware now outdated.

• See the more recent project: To automatically tune a Magnetic Loop Antenna

• Rough description of two magloop projects added 2013-07-15, including a manual controller and a fully automatic controller for tuning of magnetic loop transmitting antennas

A very simple to build, menu driven RF Power Meter, based on the AD8307 log amp

(This project is also described in QEX Magazine, May/June 2013 Edition)

• nanowatts to kilowatts, dBm, volts over 50 ohm

• 1, 2.5 or 5 second peak envelope power

• average power and amplitude modulation index

• in-line (using a power tap) or terminated metering

• Examples of displays selectable by Rotary Encoder

• Circuit Description

• Rotary Encoder and Pushbutton control menus

• Computer readable data and USB commands

• The Microcontroller Firmware

• 200W 40dB Power Tap

Last upd: 2014-04-30

• New firmware uploaded.

• V 1.08, modifications/Improvements to USB

• serial handling, in sync with the project: Power and SWR Meter with dual bargraphs, using 2x AD8307

• v 1.07, minor update, better average measurements.

• v 1.06 Added USB (virtual serial) commands

• Project added 2012-06-27

AD8317 based Intelligent Attenuator/Power Meter for 0.2 to 500 MHz

A multipurpose RF lab instrument:

1. RF power meter, 0.2 to 500MHz, input power -50 to +30dBm, 0.1dB resolution.

2. Step Attenuator, 0 - 151.5dB in 0.5dB steps.

3. "Intelligent Attenuator" or "Signal Level Generator" function, automatically adjusting to a preset output power.

Last upd: 2012-04-13

• Bugfixes and new features

• (Bargraph Power Display)

SDR Widget

A group project to develop the ideal sound card/controller for an SDR

• • • • What is it?

      • Performance

      • Pictures of various Hardware Builds:

      • --> SDR Widget evolution

      • --> Audio Widgets (hifi playback)

      • --> An All Band (160 - 10m) HF Transceiver using the SDR-Widget and Mobo 4.3

Last upd: 2011-04-17

• A full fledged sound card with superior performance, and Mobo style SDR control functions. HiFi Audio playback variants also developed. Development continues

Comparison of “conventional”, “DDC based” and “soundcard based” receivers

A rambling mini thesis on SDR performance

Last upd: 2010-07-28

Mobo 4.3 Application Programming Interface (API)

Here is the Mobo 4.3 Firmware API, as well as the complete AT90USB162 / ATmega32U2 sourcecode for download (see bottom of page).

The MoboControl GUI is available for download at the bottom of this page.

Last upd: 2017-01-20

• Uploaded a new version 1.08 of the firmware source code. The new version can be compiled using Atmel Studio 7.

• API and repository for the Mobo 4.3 firmware added on 2011-04-02

Mobo 4.3 Project - The continuing Saga of the SR 6.3 kit - Now becoming a deluxe HF Transceiver

This section includes description of a firmware development project, using the AT90USB162 microcontroller to provide Si570, and TRX control

(automatic BPF + LPF switching, PA bias, SWR measurement and protect, etc...)

• • • • Project Overview

      • Simplified Power/SWR meter head

      • Firmware Project for the Mobo 4.3 (AT90USB162 / ATmega32U2)

      • MoboControl GUI Widget

      • Build history of the Alpha version of the Mobo

Last upd: 2011-04-02

Softrock 6.3 Project - An all band HF Transceiver, based on the Softrock RXTX v6.3 kit

Including the following home brew projects:

• • • • ATmega168 based microcontroller (Si570 and TRX control) + source code;

      • Computer readable Power / SWR meter;

      • 20W HF Power Amplifier using 2 x RD16HHF1; and more

Last upd: 2011-01-16

• Added a picture from Alex, RN6LW, showing his very nice SDR transceiver, including the ATmega168 controller

• Stable since 2009-09

A 4m tall, bottomfed, electrically fullsize halfwave vertical dipole for 20m (tuneable to other bands)

Last upd: 2009-03-01