I've build the original QRP-labs U3S from stock. Means the supplied crystal on the PLL-based synthesiser-board.

This configuration is basically working up to 20m with a lot amount of drift, but you will get many decodes on wsprnet.org. On 6m you can also get spots - once a day :-/

Details
Kategorie: WSPR

I've finished my second U3s.

Details
Kategorie: WSPR

Check out my new KiwiSDR running:

 

http://dl2sba.ddns.net:8073

 

Details
Kategorie: SDR

In this post I describe in details, how you can create the calibration factors for k0 ... k3 based on raw data measured with the power sensor.

Details
Kategorie: RF Powermeter

Ich habe das Leistungsmessmodul von Oliver, DG7XO nachgebaut. Es wurde in zwei Versionen in der cqDL vorgestellt. Oliver hat mir freundlicherweise eine Platine geätzt und den AVR programmiert, so dass nur noch Löten und Mechanik angesagt war...

Details
Kategorie: Shack

Test setup

MA1

I made some measurements using my miniVNApro with a simple test fixture fittig the QRP labs lowpass filters.

Details
Kategorie: WSPR

Measurement of the signal quality of QRP-Labs U3s with low-pass filters.Transmitter output is fed into a homemade 40dB power pad. The spectrum is measured using an SIGLENT SSA3021X analyzer.
The bias voltage was about 2.6VDC and the PA voltage was abt. 7VDC.

Details
Kategorie: WSPR

My new U3S is online :-)

U3S 2

Details
Kategorie: WSPR

I've read the PA bias study from Hans and tried to tweak the PA of my U3S for optimum harmonics suppression etc. The spectrum is measured using an SIGLENT SSA3021X analyzer. The power is measured using a 40dB tap and a cheap 20w Dummyload from Diamond: ATT The tap is based on the work of OZ2CPU.

Details
Kategorie: WSPR

  1. RF Powermeter - Firmware 1.8.1
  2. RF Powermeter - Unstable reading - Reloaded
  3. hamware AT-515 Firmware
  4. hamware AT-502 - Neue Firmware
  5. hamware AT-615U Firmware
  6. hamware AT-615B Firmware
  7. hamware AT-502/AT-515/AT-615U Interface
  8. hamware AT-502 Firmware - Erweiterung für 160m und 80m
  9. hamware AT-502 Firmware - Update CI-V Schnittstelle
  10. hamware AT-502 Firmware - IRB P02
  11. hamware AT-502 Firmware - K2+RUMLOG
  12. hamware AT-502 Firmware - Kenwood erweitert
  13. GPSDO - Distribution Amplifier
  14. GPSDO - Commandline interface
  15. GPSDO - Some Measurements
  16. GPSDO - GPS Disciplined Oscillator
  17. RF Powermeter - Uploading HMI file
  18. RF Powermeter - Firmware 1.8.0
  19. RF Powermeter - Firmware 1.7.2
  20. RF Powermeter - Unstable readings
  21. RF Powermeter - Firmware 1.7.1
  22. RF Powermeter - Firmware 1.5.0
  23. RF Powermeter - Adopted Nextion library
  24. RF Powermeter - Precision
  25. SOTA - Flight deck for KX3
  26. SOTA - DM/BW-094 - Kornberg
  27. SOTA - DM/BM-344 - Kleiner Kulm - My first activation is done
  28. SOTA - Working conditions
  29. Switch-mode DC-DC converter
  30. Frog Sounds - Spurious emissions

2014 CW (Morse Telegraphy) was added to the German Nationwide Inventory of Intangible Cultural Heritage.

Regular supporter of wikimedia