Selected Projects since 2019
Published Spring 2020
Update 4/2022: RF tolerant PCB designed and built
March 2022 I designed a PCB with optocouplers located close to the IO connectors, board edge connectors and no wires except the Cabling to the combo USB/Enet jack and short lines to the optional Nextion touchscreen or small OLED displays. The power and data lines for those are EMI filtered. Band decoder line inputs to optocouplers are filtered and have isolated power and ground supplied by the radio side. The PCB was sized to slide into a common online sources aluminum box for shielding.
An easy to build and affordable RF wattmeter for HF through microwave bands
Uses an Arduino and standard surplus dual directional couplers. Uses the Arduino C. The detectors are low cost 6GHz modules. There is a companion Python V3.8 app for a PC to remote monitor and command the meter to load a specific calibration set to match yor coupler and frequency characteristics. If you use or can use WSJT-X as thousands of us do, it sends out UDP broadcasts that this remote meter app will listen to and track the radio dial frequency. It will command the meter to load a cal set to match the band in use.
Projects of note not on this website but feel free to inquire for more info:
5.7GHz surplus conversion
PIC 16F877 control for PLL and FT-817 interfacing including sequencing, Tx_Inhibit applied until correct band selected and sequencing delay finished. Can be applied fo most any transverter or amplifier.
10GHz "White box" surplus conversion
Updated recently to replace the drifty telecom brick LO with a modern external PLL (DigiLO) via a surplus x4 multiplier PCB and into an aviation surplus amp module to get the LO to +17dBm. 90mW output. Has a custom PCB to sequence -5V gate bias V, the relays for amp and preamp modules at the dish, the FT-817 IF rig and has an output power analog meter with LED peak power detect and hold LED.
Multiband LO and Remote Antenna Switch
Published Fall 2019
A DigiLO 6GHz PLL is controlled by a Cypress Semiconductor PSoc5LP to manually or automatically select the right LO frequency, output port, and level and control external equipment such selecting a transverter and/or a remote antenna switch.
Includes the remote antenna switch. Programmed in C with a complete menu driven configuration system using a 2 line LCD and rotary encoder with push switch. Featured in the January 2020 QEX magazine.