SdrDx Docs -> tuning4m
         Previous <—> Next                  HomeContentsIndex                  Guide                 BETA DOCUMENTATION

Beta Address: http://blish.org/sdrdxdoc/tuning4m.html

5.14.3 - Demodulator Mode Selection

You can do this using AM, FM, SAM, USB, LSB, ( FSL, FSU, WFM), CWU and CWL, or you can use the  A,  F,  S,  U,  L,  C, and  W keys, respectively, except for the parenthesized modes.

5.14.4 - Demodulator Bandwidth Control

Each demodulator mode recalls its upper and lower bandwidth settings, which you can adjust by pressing ^ ↑, ^ ↓, ^ → and ^ ←, or by using the left or right mouse button when pointing at the demodulator edge on the spectrum display.

5.14.5 - Demodulator Carrier Offsets

For FSL, FSU, CWL and CWL, the desired signal is not properly tuned at its carrier frequency. Instead, you need to be tuned off-side; for instance, if you want a 1 KHz tone, in CW, then you need to be tuned 1 KHz above or below the CW signal, depending on which mode you are in.

You can set standard carrier offsets with Right-click FSL, Right-click FSH, Right-click CWL and Right-click CWU such that direct frequency entry using  RETURN lands you right on the correct frequency.

For instance, there are CW beacons on 14,100.000 MHz. Use Right-click CWU and set the offset to  1000 

While you're at it, set a center offset to avoid the I/Q spike many SDRs produce: Right-click CTR and set the center offset to  10000 

Now press  RETURN, type  14100c , and bingo, you're right where you need to be, 1 KHz offset from the CW signal, and about 10 KHz away from the SDR's center frequency.

Another example, WLO RTTY on 8,473.000 KHz:

Use Right-click FSL and set the offset to  1400 

Now press  RETURN, type  8473j , and again you're right where you need to be, 1.4 KHz offset from the RTTY signal, and about 10 KHz away from the SDR's center frequency.



toc    index    guide    changes    keyboard    , previous    . next
Please consider supporting my SdrDx development efforts via a small donation.

Google
Placeholder
         Previous <—> Next                  HomeContentsIndex                  Guide                 BETA DOCUMENTATION