On this site you can find additional information on projects of mine that have been published in QST Magazine and elsewhere including firmware downloads for those requiring it.
Contact me via e-mail if you have any questions.
All circuit boards are F4, double sided, mil spec with silkscreen and solder mask and plated through holes.
Check download sections for firmware and other information .
A button can be found within each section to link to the related files.
Listed above is "Termite" a simple USB serial program to control various Arduino projects on this site. Click button to download.
Second is "Zadig", install the driver for the RTL dongle used in the SDR projects when using SDR# or HDSDR. Click button to download.
COMING SOON, A NEW 40 METER QRP TRANSCEIVER. SOON TO BE PUBLISHED IN QST. SEND ME AN E-MAIL WITH QUESTIONS.
Here is an article on how ro build a simple variable inductor for pennies. This will tune your shortened antennas for portable or emergency use. Antenna wire length details are included.
6 OR 10 METER FM SDR TRANSCEIVER
An RTL dongle provides the receive function and the design utilizes inexpensive pre-assembled modules and amplifiers.
THIS DESIGN WAS FEATURED IN THE MARCH 2019 ISSUE OF QST MAGAZINE
AND AWARDED "BEST ARTICLE".
This transceiver uses an Arduino NANO and eBay DDS AD9850 module to generate FM digital modulation without mixing on six or 10 meter band. It will operate simplex or duplex mode and supports tone. All parts are through hole and the pre-assembled module and micro just plug onto the board.
CIRCUIT BOARDS ARE AVAILABLE, $25 for board, shipping included
Non USA address add $14
1 kHz to 1.7 GHz SDR Receiver
This simple SDR up-converter/receiver will provide excellent performance over an extreme frequency range. Free HDSDR software allows you to control all demodulation specs and works on all modes
Assembled receiver for use with any computer or tablet
The design utilizes well designed front end filtering for rejection of commercial FM interference for outstanding performance. Receives CW, USB, LSB, NBFM, WBFM, AM
THIS DESIGN WAS FEATURED IN THE JANUARY 2016 ISSUE OF QST MAGAZINE AND AWARDED "BEST ARTICLE".
This board may be used to add a panadapter function to existing receivers. Just tap into the IF section.
The required SDR Dongle
This inexpensive dongle is used as the receiver function along with the free SDR software. All that is required for assembly is a few through hole parts.
CIRCUIT BOARDS AND KITS ARE AVAILABLE, $24.75for the board, $55 for the kit, and $80 Assemble and tested.
(Note, Kits and Assembled include all parts that mount on the board but no RTL dongle) Shipping included in prices
Non-USA address add $14
This analog audio notch filter and clipper also has an audio amplifier so it can function as a complete audio system for a home made receiver or can be installed with any older receiver lacking this function.
External controls allow you to set the notch frequency required across the entire audio spectrum, and set the level of clipping as necessary to limit noise bursts such as from distant lightning strikes. The notch, clipper and audio amplifier work independently or together as desired.
THIS DESIGN WAS FEATURED IN THE AUGUST 2015 ISSUE OF QST MAGAZINE
AND AWARDED "BEST ARTICLE".
FRONT VIEW WITH ADDED NOTCH FILTER
This receiver is now published in MAY 2020 issue of QST
HF CW/SSB RECEIVER
WITH ADJUSTABLE BANDWIDTH CRYSTAL FILTER, DIGITAL DISPLAY, DDS FREQUENCY CONTROL AND RF AND AF GAIN CONTROLS.
STEPS AVAILABLE: 1 HZ, 10 HZ, 100 HZ, 1 KHZ, 10 KHZ AND 100 KHZ
for ease of tuning
CIRCUIT BOARDS ARE NOW AVAILABLE
SINGLE BOARD HF RECEIVER
IN A SIMPLE HOME MADE CABINET
SEE NEW FILES AND PICTURES ADDED AND FILES TO MAKE 3D PRINTED ENCLOSURE DESIGNED BY KK6US
Note:Although built here for the 40 meter band, Changed values in the bandpass filter section allows operation on 160 to 10 Meter HF bands as well. Software covers all HF bands as written. USB not supported on bands below 40 meters. LSB not supported above 40 meters.
NEW SOFTWARE IS AVAILABLE NOW TO ALLOW USE ON USB FOR RECEIVING DIGITAL MODES ON 40 METERS. CW ALSO STILL SUPPORTED. NO HARDWARE MODIFICATIONS ARE REQUIRED.
Also now available in download section, is a circuit for adding AGC function and S-meter to the receiver.
NOTE: NEW SOFTWARE IS AVAILABLE FOR DOWNLOAD TO FIX RELAYS NOT LATCHING . GO TO RELATED FILES
HIGH FREQUENCY CW AND SSB SDR TRANSMITTER
This transmitter is a more complex project and is not recommended for the beginner builder. It operates on 160 to 10 meters QRP and has great stability due to DDS control via a Texas Instruments Microprocessor
This design was in the August 2017 QST
REAR PANEL VIEW
The design consists of three main boards. One generates all frequencies necessary and based on the tune frequency selected, switches the proper filtering in line. A second board generates the SSB signal, filters it and mixes the frequencies to the transmit frequency output. A third board filters and amplifies the signal.
You can use two boards (A & B) for an analog SSB/CW transceiver if desired and supply the local oscillator and BFO frequencies from elsewhere or modify the software to add local tuning.
FRONT PANEL VIEW
Combine this transmitter with the SDR receiver shown on this page and you will have a complete SDR transceiver. Use with any computer or tablet for control and display
A SET OF THE THREE MAIN BOARDS IS AVAILABLE. $30, shipping included
Non USA address add $14
This receiver/transceiver was featured in two issues of Ham Radio Magazine, July 1983 and November 1984
Here is a link to copies of the articles. This is included here for reference only. I have no boards for this and the design contains some obsolete components but several of the circuit designs are still useful today. I still use this transceiver at times The amplifier is not included in the documentation.