Thursday, January 6, 2011

Receiving 137kHz with the IC706

For WSPR at 137kHz to filter out the DCF39 signal at 0.1388kHz
I make use of the CW 500Hz filter in my IC706.
Receiving(only) with the IC706 in position CW-narrow using the 500Hz CW filter is possible
settings: IC706 Dial:   0.137500  mode CW-R  (for USB this must be 0.13600 to bring the audio in the center of USB filter)
WSPR: Advanced : Rx BFO (Hz) 570 (in my case) to adjust the audio at the correct frequency in the band.  (1500 by default for USB mode) 
WSPR Dial: 0.137000  Brings the displayed frequency ruler  400-600  meaning 0.137400---0.137600  
Tx  0.137500  (no TX Txfr =0)
  Decoding is good  decoding traces as low as -31db

But   i have a problem that i could not fix yet:
The reported frequency is consequent 72Hz to high for all signs.The trace position and frequency at the screen are correct.

F.i. PA0A = 0.137450 correct on the screen and also this is his correct TX frequency.  But it is reported as 0.137522kHz
I change WSPR dial  then the ruler  will display  him on the wrong freq.   If i change WSPR  Rx BFO to 500 f.i. then the position of the trace  shifts to the wrong place  and frequency.
  And the reported frequency stays wrong +72Hz.
All other bands report the frequency as displayed on the screen.
Only  137 is wrong.  

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