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I have built many radio kits over the years and to date this one is the best. I ordered the kit plus optional case (with laser etched front and rear panels) and GPS module.
The QMX+ is a twelve band (160mtr through to 6mtr) 5W max CW/digital modes transceiver. However, the latest firmware beta download now includes lower sideband and upper sideband transmit and receive.
The kit came with all bagged hardware, through hole components, toroids + enamelled wire, main six layer pcb with SMDs pre-installed, display pcb and front connectors pcb.
I had already downloaded and read through the assembly manual and it reminded me of the excellent ‘Heathkit’ instruction manuals. I had also downloaded the QMX operating manual.
Construction was done over several days and required a steady hand, reasonable eyesight, having a magnifier was a bonus, and good soldering skills. I followed the instructions to the letter. It’s certainly not a good idea to rush as mistakes will arise (I speak from previous experience). The most tedious part of the build was winding the 18 toroidal inductors (bandpass/lowpass filters) plus 2 binocular transformers (output and swr) and scraping off enamel. Also, I found the display pcb and front connectors pcb assemblies a bit fiddly. There are various DVM tests to do throughout the build.
After carefully checking my handywork several times and assembling the unit and inserting the RTC battery (2032 button cell) it was time to apply power (the transceiver can be powered from 9 volts or 12 volts) 12 volts in my case (chosen when winding the binocular transformer) and the display lit up. However, the unit required the firmware to be downloaded and installed before it would do anything. Following the instructions this was an easy operation. The QMX has a bootloader pre-installed and when connected to a pc (mac in my case) and switched on (a long press on VOL rotary encoder) it appears as a usb flash drive. I downloaded the firmware file from the QRP Labs website and dragged it across to the QMX flash drive shown on my computer. The QMX rebooted and all was well. On connecting an antenna, signals were heard on all bands. The GPS module also worked
I had the QMX+ connected to my terminated folded dipole to start with and did not have any joy with FT8 contacts. I then changed to my half wave end fed antenna and had several FT8 contacts on the 40mtr band with 3Watts.
I have the QMX+ connected to my Macbook Air running WSJT X, JT Bridge and Aether (logging software). So far all are working well. I will update the QMX firmware that will include ssb soon. However a suitable microphone will need to sought.
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