Frequency Stabilization

VHF/UHF WSPR
Frequency Stabilization

N6GN engineered this GPS disciplined frequency reference for selected stations in our West Coast VHF/UHF WSPR Study Group. It provides a 10 MHz reference as well as a GPS disciplined substitute for the master oscillator or local oscillator of various commercial transceivers or transverters. Leo Bodnar Electronics now sells a similar device.

31. N6GN engineered this GPS disciplined frequency reference for selected stations in our West Coast VHF/UHF WSPR Study Group.  It provides a 10 MHz reference as well as a GPS disciplined substitute for the master oscillator or local oscillator of various commercial transceivers or transverters.  The discussion thread can be read here. Leo Bodnar Electronics now sells a similar device.


A typical Elecraft XV144 transverter modification for GPS frequency reference. The 47Ω resistor suppresses the 116 MHz crystal oscillations and Q1 functions to amplify the external 116 MHz reference signal.

32. A typical modification to injection lock the Elecraft XV144 transverter to the GPS10V 116 MHz frequency reference. The 47Ω resistor suppresses the 116 MHz crystal oscillations and Q1 functions to amplify the external 116 MHz reference signal.


The Elecraft XV144's internal local oscillator with crystal oven option had exhibited 3-4 Hz frequency drift during 2 minute WSPR transmissions and long term frequency instability with ambient temperature variation. This frequency instability and drift was eliminated with the GPS10 frequency reference.

33. The Elecraft XV144's internal local oscillator with crystal oven option had exhibited 3-4 Hz frequency drift during 2 minute WSPR transmissions and long term frequency instability with ambient temperature variation. This frequency instability and drift was eliminated with the GPS10 frequency reference.



REFERENCES

  1. Aircraft Scatter (ACS), Larsson I, SM6FHZ
  2. WSPRnet.org
  3. Hepburn's Tropospheric Ducting Forecasts
  4. California Temperature Inversions, Iacobellis et al.
  5. 144 MHz Propagation Study across the Alps
  6. 144 MHz WSPR Operations in Australia

LINKS

  1. 2 Meter WSPR Discussion Group
  2. 144 MHz WSPR Study Photo Album
  3. 144 MHz WSPR Study Spot Database
  4. 144 MHz WSPR Study Videos - KP4MD
  5. 144 MHz WSPR Study Videos - KC6KGE
  6. 144 MHz WSPR Study Videos - N6GN
  7. 2m WSPR (Radio Stability (M1GEO)
  8. Australian 2m WSPR Group
  9. Idiot's Guide to 144 MHz WSPR (VK3BQ)
  10. WSPR Propagation Study Paths Map
  11. Google Earth KML File
  12. Current WSPRnet 144 MHz Spot Reports
  13. WSPR Spot Report Analysis Spreadsheet with Charts

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