QRP Labs QDX 20 meters Transceiver

The board is in a 3D printed case(not pretty but works)

Includes power cable, USB cable and 3D printed stand(not pretty but works)


This is a used piece of equipment. Which means it has been tested and working. If the item was not working it would be marked for Parts or Repair


Ships via USPS Ground Advantage 


I have my items packed and sealed when they are listed.  That means that they have been weighted and ready to go out. If you have questions or requests please ask before you make the purchase.  


International sales welcomed and ship through the eBay Global Shipping Center.


Shipping times will vary if going out of the country. Specified delivery times listed on the ad is to US addresses and will also vary. The eBay Global shipping center is included in that and not the final destination outside of the US.


The information listed below was found online and does not reflect what is included in the sale.  It is for reference use:

The "QDX" (QRP Labs Digital Xcvr): a feature-packed, high performance, five-band (80, 60, 40, 30 and 20m) or six high-HF band (20, 17, 15, 12, 11 and 10m) 5W Digi-modes transceiver kit, including embedded SDR receiver, 24-bit 48 ksps USB sound card, CAT control, synthesized VFO with TCXO reference. QDX transmits a SINGLE SIGNAL, it is not an SSB modulator with associated unwanted sideband and residual carrier, or intermodulation due to amplifier non-linearity. QDX outputs a pure single signal. 

QDX is available either as a KIT or as an Assembled/Tested/Adjusted transceiver: QDX is suitable only for single tone FSK modes, which covers the majority of digital modes in use today. This includes everything in WSJT-X (except MSK144), JS8Call, some fldigi modes e.g. RTTY, Olivia and more. QDX is not suitable for on/off keyed modes such as CW because it does not have click-reducing RF envelope shaping; furthermore it is not suitable for phase shift keyed modes such as PSK31 or modes involving multiple concurrent tones such as WinLink,

Many thanks to Ross VK1UN for his extensive and tireless assistance designing and testing filters for the high bands version of QDX (20, 17, 15, 12, 11 and 10m version). 

The Optional enclosure is black anodized extruded aluminium, very sturdy and elegant. The enclosure size is 89 x 63 x 25mm without protrusions. The front and rear panels are drilled and cut to match the QDX PCB with laser-etched lettering. The enclosure includes four self-adhesive feet. 

List of features: 

  • Five bands version 80, 60, 40, 30 and 20m or six high-bands version 20, 17, 15, 12, 11 and 10m
  • 5W output at 9V supply (can be built for 4-5W at 12V supply) - note lower power at higher bands e,g. 10m, approx 3.5-4W
  • Single signal transmission (zero unwanted sideband, zero residual carrier, zero intermodulation distortion)
  • Solid-state band switching and transmit/receive switching under CAT control
  • High performance embedded SDR SSB receiver with 60-70dB of unwanted sideband cancellation
  • Built-in 24-bit 48ksps USB sound card
  • Built-in USB Virtual COM Serial port for CAT control
  • Si5351A Synthesized VFO with 25MHz TCXO as standard
  • Easy to build single-board design, Professional quality double-sided, through-hole plated, silk-screen printed PCBs
  • All SMD components factory assembled
  • Connectors: 2.1mm power barrel connector, USB B (for audio and CAT control), BNC RF input/output
  • Built-in test signal generator and testing tools
  • Receive current 100mA, Transmit current 1.0-1.1A for 5W output with 9V supply (around 0.7A for 5W with 13V supply).
  • I-Q output mode if you wish to use a PC SDR program for demodulation rather than the internal SDR
  • QFU firmware update for lifetime free firmware udpates, easy installation on any PC without drivers, software or hardware e.g. programmer
  • Optional aluminium extruded cut/drilled/laser-etched black anodized enclosure (88.6 x 63 x 25 mm)

QDX works well on 60m, as documented by John AE5X at https://ae5x.blogspot.com/2021/11/spectrum-analysis-qdx-on-60m.html. Outside the range 3.4-14.5MHz, QDX can be used as a receiver, with some loss of sensitivity. Firmware versions 1.06 onward can operate on any amateur band from 2200m to 4m, but hardware changes will be needed (correct filters etc). 

NOTE: Due to the global semiconductor shortage, the price of many ICs has increased dramatically, and there have also been (less drastic) price increases in other parts of the production. Accordingly it has been necessary to pass on some of these costs to the price of the QDX, this is why it is now $69 when the original price was $60 for the first batch. The first batch was produced in Jan 2020, a whole world away. 


PC Software

Standard digi modes software like WSJT-X and JS8Call works fine with QDX, because QDX acts as a USB Sound card (for Audio) and a Virtual COM port (for CAT control).

There are three types of USB devices in QDX: USB Audio, USB Virtual COM port, and USB mass storage (like a USB Flash memory stick) for firmware update. Drivers for all of these types of audio device are already present on your PC if you are using Mac, Linux, MS Windows 10 or MS Windows 11. If you are using older versions of Windows, then you need to install a driver for the Virtual COM port (audio and USB Flash drivers are already present even on older Windows), the details are in the QDX manual.