NEW KIT: Receiver module, $25 including BPF

See - It's been a long time in preparation, but is finally ready! A receiver module to complement the QRP Labs transmitter and signal generator kits. It can be used as an SDR front end, or for WSPR reception, or in your own projects! This is a high performance receiver module with the following features:

  • Socket for QRP Labs Band Pass Filter, your choice of any band from 160m to 10m
  • Includes transmit/Receive switch 
  • High performance double-balanced Quadrature Sampling Detector (a.k.a. Tayloe Detector)
  • Low Noise LM4562 op-amps used throughout
  • Instrumentation difference amplifiers for excellent common mode noise performance
  • I-Q audio output (3.5mm jack) for driving stereo sound cards and SDR software or WSPR software
  • Tutorial provided showing how to configure WSPR in I-Q mode
  • 600:600-ohm audio galvanic isolation transformers to prevent ground loop hum
  • Requires Local Oscillator (LO) frequency at 4x the receive frequency
  • LO can be generated by QRP Labs Ultimate3S TX, VFO/SigGen or ProgRock kits
  • 80 x 37mm PCB, can fit behind the Ultimate3S TX, VFO/SigGen kits that are the same size
  • Optional SMA connector for RF input (not supplied in the kit)

NEW KIT: Polyphase network module, $11

The receiver kit (above) outputs I-Q audio that needs a PC with stereo input soundcard to demodulate. An external stereo input USB soundcard could be used but they can be expensive. So this is an optional plug-in kit that complements the new receiver module kit. It can be used to demodulate SSB (cancel the unwanted sideband) when your soundcard is mono input (many laptops and some PCs have mono input soundcards). Alternatively you may wish to construct a standalone receiver project of your own - then this polyphase network can be used to drive an audio amp, for example. LSB or USB demodulation is selectable. See for more details.

This photograph shows the polyphase network board plugged into the receiver module board, and a 30m BPF also plugged into the receiver board.

NEW KIT: 50-ohm 20W QRP Dummy Load, $8.50

See . A nice shack accessory for testing QRP transmitters etc. This dummy load kit contains two identical PCBs, and 20x 1K 1W resistors which are sandwiched between the PCBs. It has a BNC output connector. The kit also includes a simple RF detector. You can connect a DVM to the detector to get some idea of power output. An example calibration curve is provided.

QRP Labs High Altitude Ballooning

Since the July newsletter, Dave VE3KCL continued launching more balloons:

  • S-14, 11th July, landed in the Atlantic in bad weather (1 day)
  • S-15, 19th July, crossed the Atlantic and flew around Southern Europe (9 days)
  • S-16, 2nd August, landed in the Atlantic in bad weather (2 days)

Dave was on holiday at the time but didn't let that stop his ballooning activities! In fact some of the balloons were launched at sunrise from a boat on the lake! This is a new twist to the balloon story! The boat was steered at a direction and speed to match the wind, so that balloon launching was (theoretically) easier. 

The Stella1 balloon was launched from Germany by Daniel DL6OW (and friends) on 30th July, with an Ultimate3S transmitter on board. It flew for 7 hours, reaching 8700m altitude and covering 181km. The flight was short due to a balloon burst. Nevertheless it was a great first flight by DL6OW and I am sure we will see more from Daniel and his friends in the near future! See for more details. Daniel is the guy in the middle of this team photo!

Ralph W0RPK kindly provided a set of data he has been collecting on circumnavigation (round the world) flights by amateur balloons. To date there have been only 10 circumnavigation flights, the 10th being Dave VE3KCL's QRP Labs S-11 flight. These flights are operated by people such as Dave VE3KCL whose perseverance and determination eventually allowed them to pull off this ultimate challenge of high altitude ballooning! Now these achievements are all collected together, thanks to Ralph W0RPK's support, and available on this new page at QRP Labs, The Circumnavigators

Meanwhile, not a balloon, but related... Bob ZL1RS' OceanFloater buoy with QRP Labs Ultimate3S kit onboard, is still going strong in the South Pacific, after 98 days at sea! See 

Randy N4TVC STEM Camp PaGG

Every summer, Randy hosts a STEM (Science Technology Engineering and Mathematics) summer camp for all 6 of his Grandchildren. They have a construction project and also some DEstruction projects where various electronic things are educationally dismantled. This summer, Randy decided that the construction project would be the QRP Labs Clock kit!

So, six Grandchildren built six clock kits. The clock kit is supplied with a 16 x 2 LCD as the display, but is also compatible with other LCDs using the standard Hitachi display chip. So the projects used a 4-line display so that they could display additional information such as from the GPS receiver. The clock kit allows flexible configuration of the information on the display. 

What a great idea! Here are some photographs of the summer camp activities! 


73 de QRP Labs!