It has been over a year since the last QRP Labs newsletter which is very remiss of me indeed. It's been a very difficult period. Covid19 pandemic lockdown and all the family and staff challenges that brings. The huge influx of orders following the launch of the QCX-mini kit in December. Component shortages (see Wikipedia: 2020-2021 global chip shortage). Design and production issues. You name it, it happened... at times it was very hard to keep up with support, admin and running the growing business, let alone dream of finding a bit of time for R&D work. 

Anyway here's a roundup of the news, new products and forthcoming products. Many of you will already be aware of the new products but for those of you that are't on the QRP Labs group etc., this may be of interest. 

1. New product: QCX-mini CW transceiver
2. QCX-mini and QCX+ are also available as assembled, calibrated, tested radios!
3. QCX-series sales pass 15,000
4. QCX-series firmware versions T1.06, to T1.07a
5. QCX-series on 160m and other bands
6. Optimizing and tuning up your QCX-series transceiver
7. QCX-series rigs now compatible with QRP Works' SideKar Extreme
8. New product: QLG2 GNSS/GPRS Receiver (currently unavailable)
9. New product: QLG2-SE GNSS/GPRS Receiver
10. U4B balloon tracker in manufacturing phase
11. Social media, Feedback, unsubscribing

1. New product: QCX-mini CW Transceiver

In May 2020 QRP Labs replaced the amazingly popular QCX kit with the new QCX+. The QCX+ has the same circuit, and the same firmware and operating features as the original QCX, but a new physical layout and many exciting improvements including a sturdy professional black anodized extruded aluminium enclosure. QCX+ has been tremendously popular.

Nevertheless there were some people who complained that QCX+ is larger, and less suitable for portable operations such as SOTA. There were suggestions to manufacture another batch of the original QCX  whose form factor with the display and controls facing upwards, is also nicer for portable operations. But I like to go forward not backward (psychological defect, whatever) so I didn't want to make more QCX. Accordingly the QCX-mini project was born!

QCX-mini is again the same schematic, same firmware, same operation and performance, as QCX and QCX+. But in a new physical layout with a much more compact structure that fits into a much smaller enclosure (optional) sized just 92 x 63 x 25mm (3.7 x 2.5 x 1.0 inches) and weighing only 200 grams (7 ounces). The radio makes substantial use of SMD components to reduce size, however these are all factory pre-mounted so, as for other QRP Labs kits, there is no SMD soldering to do. QCX-mini features the same six connectors as QCX+ namely DC Power in, RF (BNC) and four 3.5mm stereo jacks: audio out, paddle/GPS, CAT control port and PTT/+5V. QCX-mini is also the same price ($55) though the enclosure is cheaper ($20) and due to the smaller size and lower weight, the shipping cost is also lower. 

A new feature of QCX-mini is the lower power consumption, optimized for portable operations. Compared to the original QCX and QCX+, the QCX-mini design has almost halved the power consumption in receive mode, measuring as low as 58mA. This is achieved in two ways:

1) Replacement of LM4562 op-amps IC6-10 with lower current op-amps (OPA2272). IC5 which is critical to the overall performance of the receiver, remains  a current-hungry LM4562. 

2) Use of a yellow/green backlit LCD module instead of the usual blue one; these displays are sunlight readable and readable even with the backlight switched off. Switching off the backlight saves around 15mA of current consumption. Even when on, the backlight is run at half the current of the QCX+ backlight. The backlight can be switched on/off from a menu option or triple-clicking the left button. 

QCX-mini is compatible with the TCXO option ($8.25) which is very useful for those wishing to operate WSPR. The QCX-mini kit is compatible with the 50W PA kit, and the QLG2-SE GPS kit, just the same as the original QCX. The development of the QCX-mini was public knowledge and I published several development updates on the QCX-mini web page which are themselves pretty interesting, including photos of sunlight and sunglasses testing of the display, and a long study of resolving microphony issues. The web page also contains some interesting comparison tables between the three members of the QCX-family on size, weight and current consumption. 

QCX-mini also includes a small, unpopulated PCB (requires 0603 SMD components sourcing and installation) that can be used to convert the radio to a uSDX SSB transceiver - this is a non-QRP Labs project supported by the uSDX group - but to make it convenient, every QCX-mini includes this small PCB that you can use if you wish. 

More details about QCX-mini:
Order your QCX-mini: 
YouTube video introducing the QCX-mini: 

Rev 1 PCBs (pictured) in the first batch had a rather delicate AMS1117 voltage regulator prone to failure, and several people also experienced defective supplied op-amp. In all subsequent batches (rev 2 PCBs), the voltage regulator was changed to 78M05 which is practically indestructible. Furthermore all QCX-mini boards with their assembled SMD parts are put through a test procedure involving 21 separate automated tests, in a custom-made test jig containing 55 pogo pin connections to the board under test. This is a fascinating test jig that you can see explained in detail in this YouTube video: 

2. QCX-mini and QCX+ are also available as assembled, calibrated, tested radios!

Yes, if you think the small size of the QCX-mini is more of a challenge than you'd like, if you are not as capable of soldering as you once were, or if you simply are short of time - why not purchase your CW transceiver ready-assembled! These are assembled by the QRP Labs team, then tested, adjusted (optimizing the power output, LCD contrast, BPF filter peaking, unwanted sideband cancellation) and calibrated (reference and system oscillators using GPS). Assembled transceivers come with a calibration and test script certificate showing the oscillator calibration values (reference and system oscillators), serial number of the radio, and measured power output at 12V and 13.8V supply. 

Assembled kit orders include installation of the optional TCXO module and installation of the radio in the optional aluminium enclosure, if you add these options to your order. The assembly fee is $45. At time of writing, we have several assembled QCX-mini and QCX+ radios ready to ship, but most assembled radio orders are made-to-order; the waiting list is currently short and typically at the moment your order should be shipped in less than a week. 

You can order an assembled QCX-mini or QCX+ here in the QRP Labs shop: 

3. QCX-series sales pass 15,000

It's not much more than a year ago that sales passed 10,000... and here we are, with the evolution of the QCX-series from the original "Classic QCX" to its current QCX+ and QCX-mini models, passing 15,000. At time of writing, 15,241 QCX-series kits have been sold. The high performance of the QCX-series design, feature-rich functionality, and low cost continue to make it very attractive to new and experienced CW operators alike. 

4. QCX-series firmware versions T1.06, to T1.07a

Firmware version T1.06 was released on 30-Oct-2020
Firmware version T1.06a was released on 12-Nov-2020
Firmware version T1.07 was released on 02-Dec-2020
Firmware version T1.07a was released on 07-Dec-2020

These versions can be downloaded from the files section of the QRP labs discussion group on, or a programmed chip can be purchased from the QRP Labs shop

The full description of the firmware changes is at but in summary:

  • Many changes in these firmware updates were related to improvements to the CAT control functionality. 
  • Morse prosgings AR, KN and SK/VA were added to the CW decoder and message memories; SK vs VA is a controversial and contested topic, so there is a new menu 5.7 which allows you to configure your preference! 
  • New menu 7.11 and left button triple-click for switching on/off the backlight of the display in the QCX-mini
  • Support for 160m operation
  • Sidetone volume now beeps to show you the new volume, when you change it in the menu
  • Improved 6m operation, and enabled experimental 160m version
  • Added FSKCW (QRSS) beacon capability 

To re-iterate: all QCX firmware versions are compatible with all PCB revisions of all QCX-series radio transceivers. Some firmware features may only apply to certain radios - for example, backlight control only applies to the QCX-mini, and CAT control features only apply to QCX-mini and QCX+ and newer QCX Classic PCB revisions unless you have added the necessary 3 components to your QCX Classic

5. QCX-series on 160m and other bands

Firmware version 1.06 (released 30-Oct-2020) and above, are capable of operation on 160m band. This is experimental. To use a QCX-series radio on 160m you need to use a 12MHz reference crystal for the Si5351A (and you cannot use the 25MHz TCXO option). You would also need to change the values of circuits in the Band Pass Filter (T1 long winding), Class-E resonant circuit (L4/C30) and the Low Pass Filter. On request, we are happy to supply a 160m filter with your QCX+ or QCX-mini order in place of the normal LPF; simply order an 80m radio and make a note in the customer-notes section of the order form. 

QCX-series radios can also be built for 15m, 12m, 10m and 6m bands though these are not, at first glance, available for order in the shop. The QCX firmware supports operation on these bands. As the frequency goes up, the transmitter power output is expected to decrease and so is the receiver sensitivity. Most probably on 6m and 10m a receiver pre-amplifier would be desirable. Several people have reported successful operation on these higher bands. Again, if you want us to supply you with LPF components for any of these bands, order the 17m radio and make a note on the order form, and we will substitute the 17m LPF with the one you request. Modification of the T1 windings and L4 is quite easy, just build the kit as per 17m but experimentally reduce the number of turns on L4 and T1's long winding.  

6. Optimizing and tuning up your QCX-series transceiver

To get the most out of your QCX-series transceiver, including optimizing its power output to at least 5W at a supply voltage somewhere in the range 12-13.8V, and optimizing the unwanted sideband cancellation, there's a new YouTube video which takes you through the whole process. The video is based on the QCX+ but applies equally to any member of the QCX-series transceivers, which all share common schematic, features and firmware. See 

7. QCX-series rigs now compatible with QRP Works' SideKar Extreme 

QCX-series transceivers (running latest firmware) are now compatible with the QRP Works SideKar Extreme. This is a CW aid that includes an 80-character screen which displays decoded CW from the QCX (via CAT control port). It also includes a K1EL WinKeyer, wired/wireless USB keyboard for keyboard-entered Morse and data entry; 20 messages/macros, QSO logger (1000 QSOs) with contest logging features and ADIF export. If you have an older "Classic QCX" without the actual 3.5mm stereo jack CAT serial port, QRP Works even include for free, the necessary CAT Port kit (2 resistors, a diode and 3,5mm jack) to modify your classic QCX for CAT. Remember that you will need the latest QCX firmware to support the CAT port too. 

For all QCX+ and QCX-mini owners, the CAT port is already included as a 3.5mm jack on the rear (QCX+) or side (QCX-mini) panels of the radio. 

See for more details. 

8. New product: QLG2 GNSS/GPRS Receiver (currently unavailable)

The high sensitivity QRP Labs QLG1 GPS receiver was extremely popular, and 8,000 of them were produced over five years. However by the end of 2020 it had to be retired due to higher component prices (due to the global chip shortage and a doubling of lead times for key components. 

Accordingly a new module was designed which we all QLG2 (QRP Labs GPS receiver 2) with the same price, but improved features and performance:

  • Uses the E108-GN01 module which is a multi-satellite constellation GNSS receiver; by default it receives GPS (US) and Beidou (China) satellites, but can be configured also for GLONASS (Russia) or Galileo (Europe) systems - any two systems can be configured and used at a time. 
  • This module has an onboard STM32 microcontroller that implements a USB to Serial interface for reading the GPS serial data on a PC.
  • You can also configure it with jumper wires to act as a USB to 38400 baud serial converter for CAT control of QCX-series CW transceivers
  • Includes high sensitivity magnetic-mount active antenna, with 2m coax and SMA connectors
  • Same three status LEDs (Power, Serial data, 1pps)
  • Optional (jumper configured) outputs at 2.8/3.3V or 5V level converted, for compatibility with different voltage systems. All QRP Labs kits use 5V which is the default configuration
  • Standard QRP Labs 4-pin header output, compatible with any QRP Labs kits (+5V, Gnd, Serial data, 1pps)
  • 80 x 37mm PCB which is the same size as Ultimate3S, Clock and VFO kits 
  • All SMD components are pre-installed by the factory; the only components to be soldered are the SMA connector and USB connector
  • Can be connected to a 16x2 LCD module such as used in QRP Labs kits (and commonly available elsewhere) for display of time and satellite parameters

The new QLG2 also features a new firmware update procedure developed by QRP Labs, which you will be seeing a lot more of in future kits. It's called QFU (QRP Labs Firmware Update). In firmware update mode, the device (in this case QLG2) appears to a host PC as a USB Flash drive; installation of a new firmware file is simply a matter of downloading the new firmware file from the QRP Labs website and copying it to the apparent USB Flash drive, which causes the QLG2 to receive the new file from the host PC and install it. The QFU system features:

  • NO programming hardware (only a standard USB A-B cable).
  • NO programming software (all systems have a file manager or equivalent).
  • NO driver installation (all OS already support it).
  • works on all operating systems (all versions of Linux, Windows and Mac).
  • Powerful 256-bit AES encryption so we will not have any issues with unauthorized copying. 

QLG2 is also the first QRP Labs product on the market using the STM32-series 32-bit ARM microcontroller, a powerful and inexpensive microcontroller that you will also be seeing a lot more of in forthcoming QRP Labs products. 

More information on the QLG2 is available on the QLG2 page 

Unfortunately after the production of 500 QLG2 and when they were sold out, we cannot produce more QLG2 at this time due to unavailability of the STM32 processor chip (see global chip shortage again). As soon as STM32 chips are available, we will resume production of QLG2. 

9. New product: QLG2-SE GNSS/GPRS Receiver 

QLG2-SE is a "Special Edition" QLG2. As mentioned above, the QLG2 is currently out of production due to the global chip shortage. Yet a need remains for a GPS receiver in the QRP Labs product range, since many of the kits can use GPS for frequency and time discipline. QLG2-SE is designed to fulfil this need while we wait an unknown amount of time for STM32 chips to become available again.

  • Uses the E108-GN01 module which is a multi-satellite constellation GNSS receiver; by default it receives GPS (US) and Beidou (Chinese) satellites, but can be configured also for GLONASS (Russia) or Galileo (European) systems - any two systems can be configured and used at a time. 
  • Includes high sensitivity magnetic-mount active antenna, with 2m coax and SMA connectors
  • Same three LEDs (Power, Serial data, 1pps)
  • Optional (jumper configured) outputs at 2.8/3.3V or 5V level converted, for compatibility with different voltage systems. All QRP Labs kits use 5V which is the default configuration
  • Standard QRP Labs 4-pin header output, compatible with any QRP Labs kits (+5V, Gnd, Serial data, 1pps)
  • 80 x 37mm PCB which is the same size as Ultimate3SClock and VFO kits 
  • All SMD components are pre-installed by the factory; the only components to be soldered are the SMA connector and USB connector
  • Prototyping areas
  • Part of the board may be snapped off to make the module smaller

As you can see, the feature set is basically the same as the QLG2 except for the omission of the USB to Serial converter and LCD module functionality which were provided by the STM32 microcontroller. 

10. U4B balloon tracker in manufacturing phase

Many of you will be aware of the high altitude hobby balloon tracker program that has been underway at QRP Labs for a long time, with a long list of test flights in collaboration with Dave VE3KCL. The tracker was initially called the U3B and was a derivative of the Ultimate3S kit, using the same ATmega328 processor but in a miniaturized, all SMD package. This evolved into the U4B and now uses the STM32-series of 32-bit ARM processors, which offer significantly more processor power, Flash memory and peripheral features than the ATmega328, at little or no higher cost. The photograph below shows a U4B prototype. The upper protruding section has a micro-USB socket for the programming and configuration of the U4B. In preparation for flight, this section is snapped off to reduce size and weight. 

There is a YouTube video explaining the U4B here: though there have been several recent improvements and developments since the video was made. The U4B runs a new QRP Labs operating system called QDOS - QRP Labs Disk Operating System - and with intended pun. U4B has a 128K I2C EEPROM chip which operates under QDOS as a 128K disk drive. You can edit and manage files on this disk, write BASIC programs, store data, etc. U4B now has 19 GPIO ports + I2C bus, these can be used for controlling things, or for reading sensors (9 of the GPIO are also 12-bit ADC capable). QDOS will also be appearing in more QRP Labs products in the future including QSX

The U4B is now in the manufacturing stage and we hope to have a batch of them available for sale soon. 

U4B has also been hit by the global chip shortage. Procurement of STM32 chips for the board was difficult and expensive, the chip price had risen to $12 which is more than 6x the pre-pandemic price. Additionally the SIM28M GPS module used in the test flights is on a long (and unknown) manufacturing lead time due to chip shortages. The last remaining problem to solve is a replacement GPS so that we don't have to wait for the SIM28M. Currently we are testing the E108-GN02 which is the baby brother of the multi-satellite constellation GNSS receiver module used in the new QLG2 and QLG2-SE QRP Labs modules. Initial results look promising and we now need a final flight test. 

Currently at time of writing several QRP Labs test flights are active, you can follow the links below for more details, live tracking map, photographs etc:

U4B-13 launched in Nov-2020, now on its 17th lap (circumnavigation): 
U4B-19 launched in Apr-2021, now on its 7th lap (circumnavigation): 
U4B-13 launched in May-2021, now on its 5th lap (circumnavigation):  

11. Social media, feedback, unsubscribing

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1) QRP Labs discussion group for discussion and support on all QRP Labs products
2) QRP Labs Facebook page 
3) QRP Labs is @qrplabs on Twitter 
4) QRP Labs on YouTube 

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